Property of American Airlines Maintenance · Add oil as necessary. NOTE: Change oil and filter after first 50 hours of operation, then every 250 hours of operation or every six months,

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ffi90T400sLNTIIGROUND POWER UNIT

CHAPTER2

MAINTENANCE

TABLE OF CONTENTSChapter/Section Page

SERVICING. . .2.11. General 1A. Equipment Service Life. 1B. Consumable Supplies Required for Normal Operation & Maintenance 1

2. Lubricating Instructions. . . 2A. Engine Oil Change Schedule . . 2B. Arctic Operation 3

3. Coolant Specifications & Recommendations. 3A.Speci f icat ions. . .3B.Concentrat ion. . .3C. Concentration Testing . . 4D. Coolant Change Recommendations . . . 4

4. Fuel Recommendations/Specifications. . . 45. lnspect ion . .4A. Preventive Maintenance Inspection Schedule . . . . 4B. Initial Inspection and Preparation. . 6C. Returning Unit to Service After Extended Storage . . . . 7D. Engine Fuels . . 7

LIST OF TABLESTable 1. Antifreeze Concentration Protection. . . 4Table 2. Preventive Maintenance Inspection Schedule.Table 3. Engine Fuels.

TROUBLESHOOTING . 2.21. General.2. Troubleshooting Chart . .

A. Use of the Troubleshooting Chart .B. Support Test Equipment Required.C. Component Failure

3. Schematics and \Mring DiagramsLIST OF TABLES

Table 1. Engine Troubleshooting Chart.Table 2. AC Generator Troubleshooting Chart .Table 3. Schematic Diagram Component Key and Description.

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TABLE OF CONTENTS (Gontinued)Chapter/Section Page

TR.UBLESH..TING (contin'".) airr'op tir"tr.tion"'

' ' 2-2

Figure 1. Ground Power Unit Schematic DiagramFigure 2. Ground Power Unit \Mring Diagram

REMOVAL AND INSTALLATION . 2-31. General .2. Torque Values For GeneralAssembly .3. Engine/Generator RemovalA. Canopy Removal .B, Preparation .C. Engine/Generator Removal . . . . .

4. Engine/Generator lnstallationA. Preparation .B. lnstallationC. Engine/generator Attachements

5. Generator Removal/lnstallationA. Generator Removal.B. Generator lnstallation.

6. Cooling SystemA. Radiator removal .B. Radiator installation.

7. Engine Oi l Change.8. Air Cleaner .

LIST OF lllustrationsFigure 1. Bridge Assembly .Figure 2. Engine/Generator Lifting Arrangement .Figure 3. Air Cleaner Filter

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TABLE OF CONTENTS (Gontinued)Chapter/Section Page

ADJUSTMENTSANDTEST. . . . .241. Maintenance/Repair Generator Electrical Drawer Assembly.A. DisassemblyB. Reassembly

2. System Fault Test Procedures.A. Protective System Test ProceduresB. Fault Lamp TestC. Testing Engine Fault Indicators only .

3. Circuit Card Adjustments.A. Automatic Voltage Regulator (AVR) Module .B. AC Overload Module .C. Over/Undervoltage Module .D. Over/Under Frequency Module.

4. Electronic Governor AdjustmentsA. Governors America Corporation (GAC) unit .

LIST OF lllustrationsFigure 1. Electronic Box, PCB Panel .Figure 1A. Electronic Box, Back Panel .Figure 18. Electronic Box, PCB Panel UndersideFigure 2. Fault Push-button Test Panel.Figure 3. Automatic Voltage Regulator (AVR) Module .Figure 4. AC Overload Module .Figure 5. Over/Under Voltage ModuleFigure 6. Over/Under Frequency Module.Figure 7. GAC Electronic Governor ControlFigure 8. Governor Linkage.Figure 9. Governor System Magnetic Pickup.Figure 10. GAC Control Unit Adjustments

CLEANINGANDPAINTING . . . . .2.541. Cleaning . ,42. Painting. ,

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iE90T400sLNI.J.I GROUND POWER UNIT

CHAPTER2

SECTION1

SERVICING1. GENERAL

NOTE: Servicing information in this chapter covers the Engine/Generator system only. Referto the truck chassis manufacturer's documentation in chapter 5 for truck chassisservicing.

A. Equipment Service Ufe: Undernormal operating conditions and with proper preven-tive maintenance, the GPU will provide excellent service for a period of 20,000 to30,000 hours before component overhaul is considered (depending upon local con-ditions).

B Gonsumable Supplies Required For Normal Operation & Scheduled Maintenance:

ComponentApplication

Description TrilectronPart No.

Quantity

Fuel Tank Fuel oil, Jet-A, Diesel (ASTM D975No. 2-D)

60 gal. (227.1 l tr)

Crankcase Lubricating oil 15W-40 C9SG (See nofes I A 2) 10 qts. (9.46 l t r )Lube points Grease. General Puroose as requiredRunnino oear Grease. General Puroose as requiredDoor Hinoes oit, oHio as requiredRadiator Antifreeze Bhylene Glycol (See notes a, b, & c) 5.5 sal. (20.8 l tr)Engine Fuel Filter, Primarywith water seoarator

FS1280 (Cummins) 8C0036 1 ea.

Enqine Fuel Filter. SecondaryFS5052 (Cummins) ECo036 1 ea.Enoine Oil Filter LF3345 (Cummins) ECo038 1 ea.Enoine Air Filter Eement P8288Eg (Donaldson) E85704 1 ea.NOTES: I1. While 15W-40C9SG oil is recommended for most climates, refer to Cummins@Operatiory'Mainte-nance Manual B Series Engine (supplied with this publication) for alternate oil viscosity recommenda-tions for winter and arctic climates.2. Antifreeze concentration level should not exceed recommended levels. To do so can cause coolingsystem failure.

a. A Mixture of 50o/o antifreeze and 50% w ater is required for temperatures above -34o F (-37oC).b. A mixture of 60% antifreeze and 40o/o water is required for environments below -34oF f37oq Thisprovides protection to -65oF (-54oq. NEVER exceed a 600/o antifreeze and 40o/o water mix.c. NB/ER use 100% antifreeze for makeup coolant.


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2. LUBRICATION INSTRUCTIONSTo ensure that the unit is kept in correct operating condition, it must be inspected andmaintained on a regular basis. Proper replacement of fi lters, lubricating oil, etc., atrecommended intervalswil l prevent damageto orfai lureof theunit , and provideoptimumperf ormance. The use of quality engine lubricating oils combined w ith appropriate oil drainand f i lter change intervals is a critical factor in maintaining the engine performance anddurabi l i ty.

A. Engine Oil Change Schedule: Time schedules indicated in Table 2 are based on aver-age operating conditions. lt may be necessary to change oil and air fi lters more fre-quently under severe operating conditions, such as operating in dry, hot, dustyclimates (desert), areas of high humidity (tropical), excessive periods of heavy loador frequent intermittent operations. Check the oil level after every 8-10 hours of op-eration during the break-in period (first 50 hours). Add oil as necessary.

NOTE: Change oil and filter after first 50 hours of operation, then every 250 hours ofoperation or every six months, which ever comes first.

(1) Always clean around oil f i l ler openings before removing caps or plugs.

(2) Do not over-lubricate or overfil l the engine crankcase. Use engine oil level dip-stick to check oil level.

(3) Prevent dust, dirt or water from contaminating lubricants.(4) Do not mix brands, weights or types of oi l when servicing unit .

(5) A high qual i ty SAE 15W-40 heavy duty engine oi l , which meet theAmerican Pe-troleum lnstitute (API) performance classification CUSG, is recommended.

NOTE: CC/CD or CD/SF engine oils can be used in areas where CE oil is not yet available,but the oil change interval must be reduced to one half the interval given in themaintenance schedule.

B Arctic Operation: lf an engine is operated in ambient temperatures consistently be-low -1 OoF 1-2SoC) and there are no provisions to keep the engine warm when it isnot in operation, use a synthetic CC/CE engine oil with adequate low temperatureproperties such as: 5W-20 or 5W-30. The oil supplier must be responsible for meet-ing the performance service specifications.

CAUTIONTHE USE OF A SYNTHETIC BASE OIL DOES NOT JUSTIFY D(TENDED OIL

CHANGE INTERVALS. P(TENDED OIL CHANGE INTERVAIS CAN DE.CREASE

ENGINE UFE DUE TO FACTORS SUCH AS CORROSION, DEPOSITS ANDWEAR

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iE9OT4OOSLNrrr cRouND Trufi&uNtrA SULFATED ASH LIMIT OF 1.85% HAS BEEN PI-ACED ON ALL ENGINE

LUBRICATING OII.S RECOMMENDED FOR USE IN THE CUMMINS ENGINEHIGHER ASH OILS MAY CAUSEVALVE AND/OR PISTON DAMAGE AND LEAD

TO D(CESSIVE OIL CONSUM PTION.NOTE: Additional information regarding lubricating oil availability throughout the world is

available in the " E.M.A. Lubricating Oils Data Book for Heavy Duty Automotive andIndustrial Engine." The data book may be ordered from the Engine ManufacturersAssociat ion, One l l l inois Center, 1 11 East Wacker Drive, Chicago, lL 60601, U.S.A.

3. COOIANT SPECIFICATIONS & RECOMMENDATIONS

A. Specifications: Use low silicate antifreeze which meets ASTM4985 test(GM 60 3 I M spec.) criteria.

B Concentration: Antifreeze must be used in any climate for both freeze and boilingpoint protection. Cummins recommends a 50% concentration level (40 to 60%range) of ethylene glycol propylene glycol in most climates. Antifreeze at 68% con-centration provides the maximum freeze protection and must never be exceed un-der any condition. Antifreeze protection decreases above 68%.


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iE9OT4OOSLNIIJ GRoUND PoWER UNIT

Table 1ANTIFREZE CONCENTRATION PROTECTION

Antifreeze Type Percentage ofAntifreeze

Protection toTemperature

fthylene Glycol 40o/o -10"F G23"C)50% -34"F G37'C)60o/o -65"F G54"C)68o/o 90'F F71"C)

Propylene Glycol 40% s"F G21"C)50% -27"F G33'C)60% -56"F G4g"C)68% -92"F F63'C)

C. Concentration Testing: Antifreeze concentration must be checked using a refrac-tometer (such as Fleetguard Part No.CC2800). "Floating ball" type density testersor hydrometers are NOT accurate enough for use with heavy duty diesel coolingsystems.

D. Coolant Change Recommendations: Trilectron recommends the cooling system bedrained and replaced every 3000 hours or yearly (whichever occurs first) to elimi-nate bui ldup of harmful chemicals.

. Cooling System Capacity: 5.5 U.S. gal. (20.8 liters).

FU EL RECOM M EN DATIONS/SPECI FICATIONSCummins Engine Company Inc., recommends the use of ASTM No. 2 D fuel. The use ofNo.2 Diesel fuel w il l result in optimum engine performance. At operation temperaturesbelow 32oF PoC), acceptable performance can be obtained by using blends of No.2 Dand No.1 D. The use of lighter f uels can reduce fuel economy.

WARNINGDO NOT MtX GASOUNE OR ALCOHOL WITH DTESEL FUEI- TH|S MTXTURE

CAN CAUSE AN D(PLOSION.CAUTION

THE FUEL'S VISCOSITY MUST BE KEPT ABOVE 1.3 CST TO PROVIDE ADE-QUATE FUFI SYSTEM LUBRICATION.

f NSPECTION (See Table 2):

A. Preventive Maintenance lnspection Schedule: A periodic inspection schedule shouldbe established and maintained. A suggested inspection/check schedule is providedbelow. The criteria listed meets the minimum requirements necessary to ensuresafe reliable service under normal operating conditions. lt should be modified as re-quired to meet varying operat ing and environmental condit ions.

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TABLE 2. PREVENTIVE MATNTENANCE INSPECTION SCHEDULELUBRICATION SYSTENT 125

HR250HR

375HR

500HR

625HR

750HR1 . Inspect for leaks.

2. Check oi l level.3. Change oil & filter or 6 months, whichever occurs first-ENGINE COOUNG SYSTEM1. lnspect for leaks.2. Inspect Radiator core for cleanliness3. Condit ion of belts.4. Check Coolant level add coolant as required.5' ch.ng"

"ntift"..t tolution t".h 3000 houri oiy.rrluEE"h;ver occws firsr

AIR INTAKE SYSTEM1. lnspect for leaks.2. Inspect for air restrictions.3. lnspect for corrosion.4. Change air f i l ter element.

1. lnspect fuel lines for leaks, chaffing and excessive bends2. Change fuel f i l ters3. Drain sediment from fuel tank.E(HAUST SYSTEM1 . Inspect for leaks.2. Inspect system for restrictions.3. lnspect clamps for tightness.4. lnspect for corrosion.5. Inspect muffler for security.

1. Inspect oi l l ine to turbocharger for leaks, & chaff ing.2. Inspect for excessive noise.ENGIN E E-ECTRICA L SYSTEM1. Inspect battery electrolyte level covers plates.

Check battery state of charge.3. Inspect battery hold-down.4. Inspect battery terminal for security and corrosion.


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9OT40OSLN

B Initial Inspection and Preparation:

(1) Remove all packaging material from unit.

(2) Inspect exterior of unit for damage that may have occurred during shipment.(3) Open the canopy by unlatching and lifting the rear half until it comes to rest at

a full vertical position. Inspect interior of unit for foreign material.(4) Inspect all w iring connections for security.

(5) Lower and latch the rear half of the canopy.

(6) Lift open the front canopy inspection cover located over the radiator. Removeradiator cap. Check to make certain that the coolant level is one inch belowthe f i l ler neck.

(7) lnspect battery electrolyte level. Service batteries as necessary, using distil ledwater.

(B) Connect battery.

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TABLE 2. PRB/ENTIVE MAINTENANCE INSPECTION SCHEDULE (Continued)CHASSIS & RUNNING GEAR Daily '425

HR250HR

375HR

500HR

625HR

750HR

1. Inspect doors and hinges for defects. Lubricate hinges. X X X X X X2. lnspect unit for loose nuts, bolts and missing hardware. X3. lnspect drawbar for cracks, corrosion and excessive wear. X4. Inspect drawbar latch for proper operation. X5. Inspect axles for security. X X X X X X6. Inspect t ires for wear and inf lat ion X7. Inspect wheel bearings for looseness. X X X X X X8. Repack wheel bearinqs vearlv or every 750 hours. whichever comes first.GEN ERATOFY E.ECTRICA L SYSTEM1 . Inspect generator air inlet screen and air outlet louver forobvious obstructions.

X

2. Inspect all wiring for cuts, excessive bends and chaffing. X3. lnspect generator mount bolts for t ightness. X4. Relays and Contactors:

a. Loose wires and evidence of over-heatino Xb. Contactor for loose wires X5. Generator/Engine Panel. Inspect:

a. Gauoes for proper operation, cracked olass. Xb. Switches for prooer operation Xc. Panel liqhts for proper operation Xd. Printed circuit boards for securitv. Xe. Electronic Governor module for security,loose terminals.

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iE90T40osLNlII GROUND POWER UNIT

CAUTIONBEFOREATTEMPTING TO START UNIT, PERFORM A PRE-OPERATIONAL

|NSPECT| ON (CHAPTER I ).(9) Checkfuel level by turning on the ignition switch (Referto Section 1-2). Ob-

serve fuel gauge. Service as necessary with fuel.

G. Retuming Unit To Service After &tended Storage:

(1) Remove covers and tape from all engine, exhaust and fuel tank openings.

(2) Remove covers and tape from electrical system components.

(3) Drain and refil l radiator with 50/50 mixed solution of water and antifreeze(ethylglycol) or according to a ratio for temperature as described in Para. 3,C.Coolant capacity is 5.5 gallons (20.8 It).

(4) Drain and refil l engine crankcase. Change oil fi lter.

(5) ff isopropyl alcohol (isopropanol) was added to fuel for storage, drain and refillfuel tank with diesel fuel.

D. Engine Fuels (See Table 3): The diesel engine uses #2 diesel, or fuels meetingASTM D975 Standard Specification of Diesel Fuels, or the following lighter fuels:No. 1 Diesel; kerosene; Jet A fuel, or blends of these fuels.

TABLE 3. ENGINE FUELSViscositv ASTM D-445) 1 .3 - 5.8 Centistroke (1,3 to 5.8 mm Per Second at 104oF l4f d.

Cetane Number 40 minimum. In cold weather or prolonged low (ASTM D-445) load (ASTMD-6lg service, use hiqher cetane number.

Sulfur Content(ASTM D-|29 or 1552)

Not to exceed 1% by weight.

Carbon Residue (Ra nsbottomASTM D-524 Dt89)

Not to exceed 0.25% by weight on 10To residue.

Ffash Point IASTM D-93) 125oF 6f C) min. Certain marine reqistries require hiqher flash points.

Densitv ASTM D-287) 30 to 420F Ft b eq A.P.l. at 6ooF ftf C' (.8t6 to .876 Sp. Gr).Cloud PointIASTM D-971

rcoF (lf q below lowest temperature expected to operate.

Active Sulfur-Copper Strip-Corrosion ASTM D-|30)

Not to exceed No. 2 rating after 3 hours at 122oF Feq.

Ash ASTM D-4821 Not to exceed 0.02% bv weioht.

Distillation (ASTM D-86) Curve should be smooth and continuous. Minimum 90% of fuel should evaporateat less than Ash (ASTM D482). Not to exceed 0.02% by weight.


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CHAPTER2

SECTION2

TROUBLESHOOTING1. GENERAL

NOTE: Troubleshooting information in this chapter covers the Engine/Generator sys-tem only. Refer to the truck chassis manufacture/s documentation for truckchassis repair and troubleshooting procedures.

This section contains troubleshooting information to assist in locating and correcting operatingtroubles which may develop in the generator set. Each malfunction for an individualcomponent, unit or system is followed by a list of tests or inspections which will help thetechnician to determine probable causes and conective action to take.The tests/inspections and corrective actions should be performed in the order listed.Troubleshooting is a logical and systematic process of determining and conecting the cause ofa malfunction. The process begins with verification of the malfunction. This may often involvean operational checkout of the GPU. After the trouble has been verified, identify allcomponents in the circuit whose failure could cause the symptoms observed during theoperational checkout. The technician should start by checking those items which are highest inprobability of causing the problem. Inspect and test each component, until the exact cause ofthe problem is determined and corrected.

WARNINGEXERCISE EXTREME CARE TO AVOID CONTACT WITH HIGH VOLTAGELEADS. REMOVE ALL JEWELRY, SUCH AS RINGS, WATCHES, CHAINS.

ETC., THAT COULD COME INTO CONTACT WITH EXPOSED POINTS.FAILURE TO COMPLY MAY RESULT IN SERIOUS INJURY OR DEATH TO

PERSONNEL AND/OR DAMAGE TO THE EQUIPMENT.

WARNINGEAR PROTECTION DEVICES MUST BE WORN WHEN IN THE IMMEDIATEVICINITY OF THIS UNIT DURING OPERATION. REPEATED EXPOSURE TO

HAZARDOUS NOISE CAN CAUSE PERMANENT HEARING LOSS.

WARNINGFUEL, OILS AND OTHER PETROLEUM PRODUCTS CAN READILY BE

ABSORBED THROUGH THE SKIN AND INTO THE BLOOD STREAM. WASHIMMEDIATELY AFTER COMING INTO CONTACT WITH THESE PRODUCTS.


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=.H 90T400SLNlI cRouND PowER uNtr

TROUBLESHOOTING CHARTThis troubleshooting chart (See Table 1) lists information under three headings as follows:. Problem. Cause. Remedy.

A. Use of the Troubleshooting Chart: lf the cause of a trouble is uncommon and cannotbe located using the chart, a good place to start your checks is at the last known sourceof power. Then proceed by checking each component in the circuiUsystem thoroughly.Use the schematics and diagrams. Electrical components in the troubleshooting chart(such as 51, Tl, etc.), are identified by a noun name an a corresponding symbol toidentify the item on schematic diagrams. lt is assumed that wiring and connections indefective circuits have been thoroughly checked before condemning any component(s).

B. Support Test Equipment Required:' Multimeter (Simpson 260 VOM or equivalent)' Tachometero See engine Shop Manualfor tool requirements.

G. Component Failure: Stop the engine immediately should any component fail.Practically all engine failures give some warning to the operator before the componentfails and ruins the engine. Many engines have been saved because alert operatorsheed warning signs such as a sudden drop in oil pressure, unusual noises, etc., andimmediately shutdown the engine.

SCHEMATICS AND WIRING DIAGRAMSThis troubleshooting section incorporates schematics and associated wiring diagrams for useby the technician. They should be used in conjunction with the Troubleshooting Chart (Table1 ). \Mren troubleshooting the dieselengine, the troubleshooting chart (Table 1) should be usedin conjunction with the Engine Troubleshooting and Repair Manual. The engine manualsupplies an in-depth and comprehensive troubleshooting guide with repair instructions. Theschematic and wiring diagram fold outs are found at the end of this section, they are:

. Figure 1 - Ground Power Unit Schematic

. Figure 2 - Ground Power Unit Wiring Diagram

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Table 1. ENGINE TROUBLESHOOTTNG CHARTFault & Condition Probable Cause Test, Check. Remedv

Excessive FuelConsumption.

1. Fuel leak. Checlc/conect the source of theleak.

2. Additional loading fromm alfunctioning accessories.

Check/repair accessories and ve-hicle components.

3. Poor quality fuel. Check that proper fuel is beingused. Check for contaminates.

4. Inadequate intake air orexhaust restriction.

Check/change air intake filter, andremove any restrictions found inthe exhaust.

5. Fuel pump timins. ChecUtime the pump.6. Worn or malfunctioning

iniectors.Check and/or replace injectors.

7. Valves not seatinq. Check/adjust valves.Engine hard to start orwill not start (exhaustsmoke present).

1. Engine cranking speed tooslow.

Check engine cranking RPM. Ref-er to engine will not crank orcranks slowly.

2. Starting aid needed for coldweather or not workingproperly.

Check and repair or replace coldstarting aid, if necessary.

3. Air in the fuel svstem. Bleed the fuel system.4. Fuel supply restricted. Clean or replace prefilters and

screens. Check fuel lines for re-strictions.

5. Intake air system restricted. Check intake svstem.Engine cranks but willnot start (no smoke fromexhaust).

1. No fuel in tank. Add fuel.2. Fuel solenoid not energized

open.Check for loose wires. Verify thatthe solenoid is functioning.

3. Fuelfilter clogged with wateror other contaminates.

Drain fuel - water separator or re-place fuelfilter.

4. Worn or malfunctioninginjector pump.

Loosen high pressure line at twoinjectors and visual check fuel de-livery while cranking the engine.Replace the pump if fuel is not be-inq delivered.

5. Injection pump timingincorrect.

Verify timing; time injection pump ifrequired.

Engine starts but will notkeep running.

1. ldle speed too low. Adjust governor linkage.


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9OT4OOSLN1. ENGINE TROUBLESHOOTING CHART

Fault & Condition Probable Gause Test. Gheck. Remedv

Engine starts but will notkeep running.(continued)

2. Air in the fuel system. Bleed the fuel system and checkfor suction leaks.

3. Fuel filter clogged or fuelwaxinq due to cold weather.

Drain fuel-water separator or re-place filter.

4. Fuel supply restricted. Clean or replace pre-filters andscreens and check for fuel line re-strictions.

5. Fuel contaminated. Verify by operating engine from atemporary supplv tank.

6. lniection pump out of time. ChecUcorrect pump timinq.

Rough idle, warmengine.

1. ldle speed set too low. Adiust qovernor linkaqe.2. Air fuel system. Bleed fuel system and check for

suction leaks.3. lniection timino incorrect. Check/correct ini ection timinq.4. Injector nozzles clogged or

inoperative.Replace injectors.

5. Broken enqine mounts. ChecUreplace mounts.5. Malfunctioning iniector pump.Check/replace pump.

Engine surges at idle. 1. Low fuel level in tank. Fill supply tank.2, ldle speed set too low. Check/adiust oovernor linkaoe.3. Air in the fuel system. Bleed fuel system and check for

suction leaks.4. Restricted fuel supply. Cleadreplace prefilters and

screens and check fuel lines forrestrictions.

5. Malfunctioning or worniniector pump.

Remove pump. Have pump re-calibrated or replace pump.

Fuel or oil leaking fromexhaust manifold.

1. lntake air restriction. Check/replace filter element. Re-view operation for excessive idlino.

2. Injector needle valve stuckooen.

Locate and replace malfunctioninginjector.

3. Obstructed turbochargerdrain line.

ChecUclean line.

4. Turbocharger seals leakingoi l .

ChecUreplace turbocharger.

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Table 1. ENGINE TROUBLESHOOTING GHARTFault & Gondition Probable Cause Test. Check. Remedv

Engine will not reachrated speed whenloaded.

1. Throttle linkage incorrectlyadjusted.

Check throttle linkage adjustmentfor full travel to the high idle stopscrew.

2. Fuel supply restricted. Change the fuelfilter and checkfuel line, pre-filter and screens forrestrictions.

3. Electronic governorincorrectlv adiusted.

Adjust govemor speed screw.

4. Malfunctioning injectionpump.

Replace injection pump.

Low power 1. Lubricatins oil level too hiqh. Drain oil to proper level.2. Throttle linkage adjustment

wrong.Check and adjust throttle for fulltravel of the fuel control lever.

3. Low intake air temperature(below 0"C [32"F]).

Allow engine to warm up to propertemperature before attempting tobrinq it up to RUN speed.

Engine misfiring. 1. Contaminated fuel. Verify by operating from a tempo-rarv suoolv tank.

2. Air in the fuel system. Bleed fuel system and check forsuction leaks.

3. Fuel iniection lines leakino. Inspect and replace broken lines.4. Incorrect valve adjustment. lnspect push rods, springs and ad-

iust valves.5. Injector nozzles clogged or

inooerative.Replace injectors.

6. Injector pump timingincorrect.

ChecUtime injection pump.

Fuel knock. 1. Poor qualitv fuel. Drain tank, fill with conect fuel.2. Air in fuel system. Bleed fuel system and check for

suction leaks.3. Inconect injection pump

timino.Check pump timing.

4. Injection nozzlesmalfunctioninq.

Remove nozzles. Test and repair.

Engine will not crank orcranks too slowly.

1. Battery voltage low. Remove and load test battery. Re-charge battery.


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Table 1. ENGINE TROUBLESHOOTING CHARTFault & Condition Probable Gause Test. Gheck. Remedv

Engine will not crank orcranks too slowly.(Cont 'd)

2. Defective fuse (F2) or circuitbreaker C82.

Check fuse (F2) and circuitbreaker CB2 for open. Replace ifdefective.

3. Starting circuit connectionsloose or corroded.

Check and tighten connections.

4. No voltage to solenoid. Check wiring, perform voltagecheck at solenoid.

5. Solenoid or starting motormalfunctioninq.

Replace starting motor.

6. Starting motor operating butnot cranking the engine.

Remove the starting motor andcheck for broken teeth on the fly-wheel or startino motor sorino.

Alternator not chargingor charging is notsufficient.

1. Loose or corroded batteryconnections.

Clean/tighten battery connections.

2. Alternator belt slippino. Check/replace belt tensioner.3. Alternator pulley loose on

shaft.Tighten pulley.

4. Malfunctioninq alternator. Replace alternator.Engine will not start. Nofault indicators ON.

1. Low battery voltage. Check battery connections.Tighten if necessary. Perform loadtest on battery, recharge if neces-sary.

2. Defective ignition switch (S1).!\4th switch set at ON, check volt-age at switch (424 VDC), re-place if defective.

3. Defective RUN/IDLE switch(s14).

Check switch, replace if defective.

4. Defective starter solenoid. Check starter solenoid, replace ifdefective.

5. Defective starter. Check starter, replace if deter-mined it is defective.

6. Defective fuel solenoid. Check fuel solenoid.7. Defective K7 relay. Check N.C. contacts to open when

enerqized.8. Defective time delay relay K8.Check relay K3 for fused N.O.

contacts. Replace if defective.Engine will not start.Control power ONindicator not il luminated.

1. lgnition circuit breaker (CB3)tripped.

Reset circuit breaker C83.

2. Defective fuse (F2). Check fuse F2, replace if defec-tive.

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9OT4OOSLNI GROUND POWER UN|TTable 1. ENGINE TROUBLESHOOTING CHART

Fault & Condition Probable Cause Test. Check. Remedv

Engine will not start, noreading on fuel gauge.

1. Low fuel. Check fuel gauge. Fill fuel tank ifrequired.

2. Defective fuel level sendingunit.

Check sending unit. 35t10 Aohms full, 250t10 O emotv.

High water temperatureindicator ON.

1. High water temperature. Check water temperature levelqauqe & fluid level in radiator.

2. High water temperatureswitch defective.

Check high water temperatureswitch 53 for short, replace if de-fective.

Overspeed indicatoroN.

1. Overspeed condition,govemor needs adjustment.

Reset overspeed switch and ad-just govemor to 2000 RPM if usingMarathon@ generator or 24OORPM if usinq Kato@ oenerator.

2. Defective overspeed switchcircuit in the electronicqovernor control module.

Perform continuity check on termi-nals 1 and 2. Circuit should beopen below 2800 RPM.

Low oil pressureindicator ON.

1. Low oil pressure. Check oil dip stick. Add oil as re-quired.

2. Low oil pressure switchdefective.

Check low oil level pressure switchfor binding or short. Replace if de-fective.

Engine will not go toRUN speed.

1. Defective RUN/IDLE switch(s14).

Wth 514 in the RUN position,check for continuity. lf switch con-tacts are ooen. replace switch.

2. Defective governor actuator. Check actuator for freedom ofmovement. Check coil for open orshort.

3. Maladjusted or defectivemagnetic pickup (MPU).

a. \Mth engine off, turn MPUclockwise until contact withflywheel is made, then turnCCW one (1) ful l turn.

b. Check MPU for 50-350 ohms.Replace MPU if defective.

Engine shuts off. Faultcondition exists, butfault indicator does notlight. Indicators checkOK with testpushbuttons.Overspeed indicatordoes not light.

1. Open diode CR21 on DiodeLooic Board.

Replace Diode Logic board.

Defective overspeed indicator(DS16).

Replace indicator if defective.


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Table 1. ENGINE TROUBLESHOOTING CHARTFault & Condition

High temperatureindicator does not light.

1. Open diode CR22located ondiode looic board.

Replace diode logic board.

2. Defective high temperatureindicator (DS1


Low oil pressureindicator does not light.

1. Open CR20 on diode logicboard.

Replace diode logic board.

2. Defective low oil pressureindicator (DS14


Fuel level gaugeinoperative.

1. Defective fuel level gauge. Check tor 12|24VDC at gauge.Check fuel level sender. Replacegauge t'f 12|24VDC is availableand sender checks OK.

2. Defective fuel level sender. Check wiring to the sender.Engine will not shut off,fault indicator ON.

1. Defective fault relay K7. Check K7 coil for open. Replace if

2. Defective relay K48. Check coil for open. Check con-

Engine will not shut off.No fault l ightsilluminated, but faultcondition observed.

1. Overspeed condition -Defective contacts onoverspeed switch (S5).

contacts on overspeedswitch. Replace if defective.

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907H e0T400sLNIJ GROUND POWER UNITTable 2. AC GENERATOR TROUBLESHOOTTNG CHART

Fault & Condition Probable Gause Test, Check. RemedvNo AC voftage. Engineat RUN speed, no faultindicators ON,frequency at 400 Hz.

1. Voltmeter selector switch setto OFF.

Set switch to L1, L2 or L3.

2. Defectivevoltmeter. Oheck voltage at meter, if 115VACis obtained, replace meter.

No AC voltage. Engineat RUN speed, no faultindicators ON.

1. Defective RUN/IDLE switch. With ignition switch in ON position,set S14 to RUN. Check S14 wire#303 for 12|24YDC. Check wire#326for 12|24VDC. Replace S14if voltage is on wire #303 and NOTon wire #326.

Automatic Voltage Regulator(AVR) fuse blown or AVRdefective.

Check fuse on AVR. Check24VDC to AVR. Check generatorfield windings. Replace AVR iffuse and generator field checksOK and 24VDC is obtained atAVR.

3. Defective generator exciterfield.

Perform continuity test betweenF1 -F2.

4. Defective power supply. Check condition of transformer T1,terminals 1 thru 9. lf transformerchecks OK. chanqe oower suoolv.

5. Defective supply transformerT1.

Inspect T1 for loose, bumed, orshorted wiring, terminals 1 thru 9.

6. Defective diodes in generatorfield exciter.

Check diodes for open, replace ifdefective.

Low/High AC voltage,no control. Engine atRUN speed,undervoltage indicatoroN.

1. Defective fuse(s). Check fuses F3-F5. F6-F8.2. Defective or maladjusted R32

on the Automatic voltageRegulator (AVR) board.

Adjust R32. Counterclockwise in-creases output. lf no change inoutput, replace AVR.

3. Defective supply transformerT1.

a. Inspect T1 for open, loose orburned wirino.

b. Check fuses F3 - F8.4. Defective volts adjust

potentiometer.Measure R5 for 0 to 1.5K ohms.

5. Defective generator exciterfield diodes.

Check diodes for open.


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Table 2. AC GENERATOR TROUBLESHOONNG CHARTFault & Condition Probable Cause Test. Check. Remedv

Low/High AC voltage,no control. Engine atRUN speed,undervoltage indicatorON. (Continued)

6. Defective sensing relay Klremote sensing assembly.

With unit running, S40 inREMOTE position and K1OFF, measure voltage onterminals 3, 6, & 9 on theremote sense board. Recordreadinqs.

b. Connect AC output to 301(\/4loadbank.

c. Apply load (Kl ON), observevoltmeters on loadbank forvoltaqes on all three ohases.

d. Verify voltages on terminals3,6,9 on the remote senseboard.

(1) lf remote sense is working,meter readings will equalvoltmeter readings onloadbank. Terminals 3=A,6=8, 9=C phase.

(2) lf remote sense is notworking, voltage measured atterminals 3,6,9 will equalmeasurements taken in stepa and voltage observed onloadbank meters will be low.

AC output voltage high.No control. Shuts downon overvoltage.

1. R32 on the AVR boarddefective or adjustedincorrectlv.

Adjust R32. Clockwise decreasesoutput.

2. Defective R5 potentiometer.Check R5 for 0 to 1.5K ohms.3. Defective supply/sensing

transformer T1.Check Tl output for 8 to 9 VAC,terminals 7,8,9. Replace if low.

No AC output voltage atcable connector. ACvoltage at panel meter.

1. Defective Kl output contactorrelay.

Check for 12VDC at coil. lf OK,replace coil.

No AC output voltage atcable connector.

1. Overload indicator ON.Overload condition.

Check GPU for overload. Removeoverload and reset.

2. Overload indicator ON.Defective AC overloadmodule.

lf indicator stays ON with overloadremoved, replace overload mod-ule.

3. Overload indicator ON.Defective relay K5.

Check relay K5. Replace if defec-tive.

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907H gOT4OOSLNLl cnouuo powen uulrTable 2. Ac GENERATOR TROUBLESHOOTTNG CHART

Fault & Condition Probable Cause Test, Gtreck, RemedyOver or Under (O/U)frequency indicator ON.

1. O/U frequency conditionexists. R8 not properlyadiusted.

Adjust frequency adjust potenti-ometer R8 to obtain 400 Hz onmeter.

2. Defective or binding actuator.Check actuator for binds. Replaceif defective.

3. Defective over frequencymodule.

lf indicator stays ON, but fre-quency is correct, replace over/un-der frequency module.

Over voltage indicatoroN.

1. Overvoltage condition.voltage adjust potentiometer(R5) not properlv adiusted.

Adjust R5 to obtain proper voltage.

2. Potentiometer R32 on AVRnot adjusted properly or isdefective.

Adjust R32. lf no change in output,change AVR.

3. Over/Under voltage moduledefective.

Reset AC. lf voltage stabilizes at115 VAC and after 5 to 7 secondsthe overvoltage indicator turnsON, chanqe the module.

4. Defective power supply. Check condition of transformer T1,terminals 1,2,3,4,5,6. l f t rans-former checks good, changepower supply.

5. Defective voltaqe requlator. Replace voltage reoulator.6. Defective supply/sensing

transformer T1.Replace supply/sensing trans-former T1.

7. Defective voltage adjustpotentiometer R5.

Replace voltage adjust potenti-ometer R5.

8. Defective generator exciterfield diodes.

Check diodes.

Under voltage indicatoroN.

1. Undervoltage conditionexists. Voltage adjustmentpotentiometer R5 isincorrectlv adiusted.

Adjust R5 to conect voltage.

2. Over/Under voltage (O/U)module defective.

Reset AC. lf AC voltage stabilizesat 115VAC and after 5 - 7 secondsthe indicator illuminates, changeO/U voltaqe module.


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Table 2. AC GENERATOR TROUBLESHOOTING CHARTFault & Condition Probable Cause Test. Check. Remedv

AC output voltageadjustment rangelimited. Voltage cannotbe adjusted to 11SVACline to neutral or200VAC line to line.

1. Defective voltage adjustootentiometer R5.

Check R5 for opens or intermittentreadings. Replace if defective.

2. Voltage regulatorpotentiom eter incorrectlyadjusted.

Set voltage adjust potentiometerR5 on control panel at mid point.Adjust potentiometer R32 on volt-age regulator board for a readingof 200VAC line to line on the ACoutput voltmeter.

Panel lights andinstrument lights do notlight.

1. Instrument circuit - Opencircuit breaker.

Reset circuit breaker.

2. lndividual panel lights do notliqht - Blown lamp.

Replace lamp.

Individual fault lampdoes not light whenFault Lamp Testpushbutton is pressed.

1. Blown lamp. Replace lamp.2. Defective diode. Check diode for open: CR6 = UA/;

CR8 = OA/; CRS = O/F, CR4 =U/F; CR7 = O/L; CR11 = Hi Tem-perature; CR10 = Overspeed; CR9= Low oil pressure. Replace diodeloqic board.

lndividualfault l ightdoes not light.

1. Defective diode. Check diode for open: CR17 =UA/; CR19 = OA/; CR16 = O/F;CR15 = U/F, CR18 = O/L, CR22=HiTemperature; CR21 = Over-speed: CR20 = Low oil pressure.

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Table 3. Schematic Diagram Gomponent Key And DescriptionItemNo. Nomenclature Location Functional descriotionA1 Automatic Voltage

Reoulator (AVR)Electronic Box Assy Maintains voltage at preset level under

all load conditions.A2 Over/Under Voltage

ModuleElectronic Box Assy Protects aircraft and generator from

over/undervoltaoe conditions.A3 Over/Under Fre-

quencv ModuleElectronic Box Assy Protects Aircraft and Generator from an

over/under frequency condition.A4 Overload Module Electronic Box Assy Protects generator from overload condi-

tion.A5 Power Supply Mod-

uleElectronic Box Assy Provides control voltage for protective

circuit operation and rectifies voltage forgenerator field operation.

A6 Diode Loqic Board Electronic Box Assy Erring diodes for circuit operation.A7 Remote Sense Mod-

uleElectronic Box Assy Allows voltage regulator to sense load

conditions at the end of the cable. Pre-cise voltage regulation is maintained atthe cable end under all load conditions.

A8 Electronic GovernorControl

Electronic Box Assy Provides engine speed control, gain andstabilitv.

A13 Relav Module Bd. Electronic Box Assv Mounts relays K2,K4, K5, K6, K7, K10ACT Govemor Actuator Engine Fuel control actuator. Receives signal

from A8 and moves throttle linkage tocontrol enqine speed.

ALT(G2)

Alternator Engine Battery charging.

8',1 ,2 Battery Frame 12 VDC or 24 VDC source for enginestartino and control.

cBl Circuit Breaker Engine Control Panel Protects governor control unit and har-ness. 10 Amp

cB2 Circuit Breaker Engine Control Panel Instruments and harness protection 5Amo.

cB3 Circuit Breaker Engine Control Panel Engine ignition and hamess protection.15 Amp

cR4-8Diode Diode Logic PC Board Lamp Test Circuit, one point ground tolamos test DS7. 8. 9. 10. & 1 1.

cRg,10,1 1

Diode Diode Logic PC Board Lamp Test Circuit, provides for 1 pointqround to lamos test DS14.15. & 16.

cR15-19

Diode Diode Logic PC Board Generator fault circuit - lsolates A2, A3and A4 durinq lamp test of DS7 to 10.

cR20 Diode Diode Logic PC Board Engine fault circuit - lsolates K7 duringlamp test of DS14.


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Table 3. Schematic Diagram Component Key And Description

ItemNo. Nomenclature Location Functional desc ription

cR21 Diode Diode Logic PC Board Engine fault circuit - lsolates K7 duringlamp test of DS16.

cR22 Diode Diode Logic PC Board Engine fault circuit - lsolates K7 duringlamo test of DS15.

cR29 Diode Diode Logic PC Board Blocking diode. Prevents power backfeed from 56 to A4,5.

cR30 Diode Diode Logic PC Board Blocking diode. Provides isolated groundpath for fault relay K7 during low fuelquantitv fault conditions.

cR31 Diode Diode Logic PC Board Blocking diode. Prevents power backfeed to pin E of output cable when 56 isin the interlock/bvoass oosition.

cR32 Diode Diode Loqic PC Board Steerino diode.cR33 Diode Loqic PC Board Steerino diode.cR34 Diode Diode Logic PC Board Engine fault circuit, isolates low oil switch

from other fault indicators.cR35 Diode Diode Logic PC Board Engine fault circuit. lsolates overspeed

switch from other fault indicators.cR36 Diode Diode Logic PC Board Engine fault circuit. lsolates high tem-

perature circuit from other fault indica-tors.

cR41 Diode Diode Loqic PC Board Arc suporession diode.cT1 Current TransformerContactor Panel Provides current signal (A phase) to

power supply module then to overloadmodule.

cT2 Current TransformerContactor Panel Provides current signal (B phase) topower supply module then to overloadmodule.

cT3 Current TransformerContactor Panel Provides current signal (C phase) topower supply module then to overloadmodule.

cT4 Meter Transformer Contactor Panel Provides current signal for A phase am-meter readinqs.

cT5 Meter Transformer Contactor Panel Provides current signalfor B phase am-meter readinos.

cT6 Meter Transformer Contactor Panel Provides cunent signal for C phase am-meter readinqs.

DS1 Indicator, AC LoadON

Generator Control Panel llluminates when load contactor is ener-gized and generator voltage is applied toload.

DS4 Lamp Enqine Control Panel l l luminates oil pressure qauqd (Mg).

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Table 3. Schematic Diagram Component Key And DescriptionItemNo. Nomenclature Location Functional descriptionDS5 Lamp Ensine Control Panel l l luminates water temp. qauqe (M10).DS7 Indicator, Overload Generator Control Panel llluminates when overload fault has oc-

curred.DS8 Indicator, Overvolt-

aoeGenerator Control Panel llluminates when an overvoltage condi-

tion has occuned.DS9 lndicator, Undervolt-

aqeGenerator Control Panel llluminates when an undervoltage condi-

tion has occuned.DSlO lndicator Underfre-

quencvGenerator Control Panel llluminates when an underfrequency con-

dition has occurred.DS11 Indicator, Overfre-

quencvGenerator Control Panel llluminates when an overfrequency con-

dition has occurred.DS14 Fault lndicator, Low

oilEngine Control Panel ll luminates when a low oilfault condition

has occurred.DS15 Fault lndicator Water

TemperatureEngine Control Panel llluminates when high water temperature

fault condition exists.DS16 Fault Indicator, Over

SpeedEngine Control Panel Engine Panel: l l luminates when an over-

soeed fault condition occurs.DS17 Lamp Canopy, over control

panel.ll luminates control panel.

DS21 Lamp Engine Panel l l luminates when ignition switch S1 isplaced to ON.

DS22 Lamp Canopy roof Low fuel quantitv warnino liqht.DS27 Lamp Canoov roof Anti-collision liqht.DS3OLamp Enqine Control Panel llluminates batterv volt meter.DS31 Lamp Enqine Control Panel ll luminates fuel qauqe (M8).EXC Generator windino Generator Exciter windino of qenerator.F2 Fuse. 20A Contactor Panel Main power/Hamess protection.F3 Fuse 5A Electronic Box Assy. Hamess instrumentation protection (A

phase).

F4 Fuse 5A Electronic Box Assy. Hamess instrumentation protection (Bohase).

F5 Fuse 5A Electronic Box Assy. Hamess instrumentation protection (0ohase).

F6 Fuse 5A Electronic Box Assy. Remote sensino. A phase protection.F7 Fuse 5A Electronic Box Assv. Remote sensinq. B phase protection.F8 Fuse 5A Electronic Box Assv. Remote sensinq, C phase protection.F9 Fuse 5A Electronic Box Assv. Generator fault circuitry protection.Fl0 Fuse 5A Electronic Box Assy. Circuit protection, power supply bd.F11 Fuse 5A Contactor Panel Circuit protection, Kl output contactor

coil.


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Table 3. Schematic Diaqram Componerrt KeV And DescriptionItemNo. Nomenclature Location Functional descriptionFLS Sender, Fuel Level Fuel Tank Fuel Tank level siqnalfor M8.FS Fuel Solenoid Enqine Controls fuel suoolv to iniector Dump.G1 Generator Frame Produces 115/200VAC 400 Hz.G2

(ALT)Alternator Engine Produces 12VDC for battery charging

and control cirucit operation.K1 Output Contactor Contactor Panel Applies or disconnects generator output

power to load.K2 Relav. Hold-in Relav Module Board Hold-in relav for Kl contactor.K4 Relay Relay Module Board Disconnects output contactor from load

during any detected generator fault con-dition.

K5 Relay Relay Module Board Provides discharge path for capacitor onoverload module during Fault Reset func-tion.

K6 Relay Relay Module Board Disconnects voltage regulator (AVR) dur-inq overvoltaqe and overload conditions.

K7 Engine Fault Relay Relay Module Board Provides voltage to fuel solenoid throughN.C. contacts. lnterrupts power to fuelsolenoid when energized by any enginefault detection circuit.

K8 Relay Contactor Panel Low oil pressure fault delay. lnterruptslow oil pressure fault circuit when ener-gized, enables fault circuit in N.C. posi-tion.

K10 Interlock Relay Relay Module Board Provides ground tor l(2 relay when Gen-erator InterlocUBypass switch is placedin the lnterlock oosition.

K42 Relay Contactor Panel Provides power to hourmeter M12 whenenergized. K42 is energized wheneverenoine oil oressure is more than 10 osi.

K45 Ether Start Solenoid Ether Start Assembly \Mren energized, provides ether to injec-tor oumo assemblv.

K48 Solenoid Contactor Panel Provides power to engine mountedstarter solenoid.

K50 Relay Contactor Panel Provides power to low fuel waming lightwhen activated bv low fuel switch S39A.

M1 Meter, Current Generator Control Panel Indicates amount of current being drawnbv load.

M2 Meter, Voltaqe Generator Control Panel Indicates oenerator output voltaoe.M7 Meter, Frequencv Generator Control Panel Frequency of qenerator output.M8 Gauoe. Fuel Level Enqine Control Panel Displavs fuel level in fuel tank.

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90T400s)OT4OOSLNROUND POWER UNIT

Table 3. Schematic Djgglqrn Cqmponent Key And DescriptionItemNo. Nomenclature Location Functional descriptionM9 Gauqe. Oil PressureEnsine Control Panel Displays engine oil pressure.

M10 Gauge, Water Tem-perature.

Engine Control Panel Displays engine coolant temperature.

M11 Voltmeter Engine Control Panel Displays Battery/Altemator voltage whenignition switch in in ON position.

M12 Hourmeter Enqine Control Panel Records engine operatinq time.MPU Magnetic Pickup Engine Govemor System - Provides engine

speed signal to govemor control from en-gine flywheel.

OPS Pressure Sender Engine Engine Oil Pressure Sender signal for oilpressure gauqe (M9)

R5 Potentiometer Electronic Box Assv. Voltage adiust potentiometer 1 .5K,2WR9 Resistor Contactor Panel, on TDI Low oil pressure fault delay relay, current

limiting resistor to set length of time de-lay.

S1 Switch, lgnition Enqine Control Panel Main Power ON/OFF.S2 Switch, Ammeter

Phase SelectorGenerator Control Panel Selects desired phase for cunent moni-

torino.S3 Switch, Volt Phase

SelectorGenerator Control Panel Selects desired phase for voltage moni-

torinq.s4A Load ON Switch,

N.O.Generator Control Panel Load ON switch to control AC output.

s4B Load OFF Switch,N.C.

Generator Control Panel Load OFF switch to controlAC output.

S6 Toggle Switch SPDT Electronic Box Assy. InterlocUBypass select switch for poweroutput control.

s11 Toggle Switch, FaultReset

Generator Control Panel Resets generator fault circuits.

s13 Pushbutton Switch ,Enqine Start

Engine Control Panel Pushbutton switch engages starter mo-tor.

s14 Toggle Switch,IDLE/RUN

Engine Control Panel Govemor/Generating System - Two posi-tion switch, IDLE position = 800 RPM,RUN position = 2400 RPM for generatorooeration.

S16A,B

Switch. Oil PressureEngine Low oil pressure fault circuit. N.C. switchopens on rise of oil pressure to above 6psi. Closes below 10 psi and activateslow oilfault circuit.


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Table 3. Schematic Diaqram Gomponerrt Kev And DescriptionItemNo. Nomenclature Location Functional desc riptions17 Switch, Engine Tem-

peratureEngine Engine fault circuit - N.O. switch closes

when water temperature rises above225F activating the engine high waterfault temperature circuit.

s18 Switch, Panel l iqhts Enoine Control Panel Operates control panel lamp DS17.s21 Fault Lamp Test,

Switch, N.O.Generator Control Panel Press-to-test fault lights.

s32 Switch, PushbuttonN.O.

Side of Electrical DrawerAssemblv

Simulates overload condition.


Side of Electrical DrawerAssembly

Simulates Underfrequency condition.


Side of Electrical DrawerAssembly

Si mulates Overfrequency condition.



Simulates Overvoltage condition.



Simulates Undervoltage condition.

s37 Switch. Pushbutton Side of Control Panel Ether start pushbutton switch.s38 Switch, TemperatureEngine Temperature switch. Opens when warm,

disconnectino ether start svstem.S39A Switch, Fuel Level Fuel Tank Fuel level switch, when level is low, lights

warning light. At lower level, creates faultand shuts-down enoine.

s40 Switch, Toqqle Electronic Box Assv. Local/Remote Sense select switch.SM1 Starter Motor Enoine Enoine mounted starter motor.SS1 Starter Solenoid Enqine Starter Enoine starter mounted control solenoid.T1 Transformer Electronic Box Assy. Transformer, voltage sense and power

suoolv.TB1 Terminal Board, 18

PointElectronic Box Assy. Terminal board, 18 point.

TB1 Terminal Board, 5Point.

Left Side of Engine. Terminal board, 5 point.

TB.2 Terminal Board,4Point

Left Side of Engine. Terminal board, 4 point, generator outputconnections.

TB3 Terminal Board, 18Point

Contactor Panel Terminal board, 18 point

TB6 Terminal Board,22Point

Contactor Panel (on edge)Terminal board, 22 point

TD1 Relay, Time Delay Contactor Panel Time delay relay used to lock out low en-gine oil pressure fault circuit during en-gine start.

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Table 3. Schematic Diagram Gomponent Kev And

Sender, Water Tem- Engine water temperature signal for wa-

Metal Oxide Varistor Mounted on Relay K1 Metal Oxide Varistor (MOV). Protects


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gOT4OOSLNGROUND POWER UNIT


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CHAPTER2

SECTION3

REMOVAL/INSTALLATION1. GENERAL

NOTE: Removal/installation information in this chapter covers the Engine/Generator systemonly. Refer to the truck chassis manufacturer's documentation for truck chassis repairand troubleshooting procedures.

This section contains instructions for removal and installation of ground power unit majorcomponents. All major components can be unbolted and removed from the GPU. Componentboards can be unplugged, and mounting hardware removed.Removal/lnstallation instructions for engine subassemblies i.e., water pump, fuel pumpinjectors etc., can be found in the engine Operation and Maintenance Manual for the engineutilized.

2. TORQUE VALUES FOR GENER^AL ASSEMBLYThe torque chart value (Chapter 5) is provided for reference when performing generalassembly of various components. These values should be used only if torque values are notothenrvise specified for a particular assembly. For an example refer to Chapter 5,Manufacturers'Appendices for engine assembly or other components assemblies which mayrequire special torque specifications.The following conditions must be observed when using the general assembly torque values:. Joints are assumed to be metal and rigid. Do not use these values where gaskets or

compressed material may be damaged by over-torquing.. During disassembly, note bolt head marking and always reassemble the same hardware or

equivalent new hardware in the conect locations.. As a general, when reusing previously removed hardware, apply the minimum values from

the table.. Reduce the Table values by 2oo/o when assembling plated hardware or phosphate coated

hardware.. Reduce Table values by 30% when molykote, white lead, or similar mixtures are used to

lubricate threads.. Reduce the Table values by 35% when torquing jam nuts (thin nuts).. Special use column values in the Table are for capscrews in gray iron castings when threads

length engagement is at least 1.5 times the capscrew diameter.


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it90T400sLNI I IGROUND POWER UNIT

WARNINGBEFORE STARTING ANY INSTALLATION OR REMOVAL PROCEDURES,

TURN THE ENGINE OFF BY PLACING THE IGNITION SWITCH TO THE OFFPOSITION. DISCONNECT BATTERY LEADS FROM THE BATTERY

(NEGATTVE GROUND LEAD DTSCONNECTED BEFORE THE pOStTtVELEAD).

3. ENGINE/GENERATOR REMOVAL

A. Canopy Removal (Refer to il lustrations in Chapter 4):

(1) Open rear canopy half and support canopy by placing a suitable brace of at least46 inches (1168mm) in height under canopy. This will prevent the canopy fromfalling once the canopy retaining rods are removed.

(2) Remove bolt and nut and remove retaining rods.

(3) The canopy pin hinges are of the separating type. Lift the canopy roof off of thesupport brace and slide the entire assembly to the left until hinge assemblyseparates.

(4) Unbolt and remove the front canopy half.

B. Preparation for Engine/Generator Removal:

(1) Drain oil from engine.

(2) Remove remote oil drain hose from engine.

(3) Remove exhaust piping from muffler to exhaust discharge.

(4) Remove exhaust piping from turbocharger to muffler.

(5) Remove mutfler retaining strap.

(6) Remove muffler from mounting bracket.

(7) Remove muffler mounting bracket.

(8) Drain radiator.

(9) Remove radiator hoses.

(10) Remove the 10 bolts holding the fan shroud. Allow shroud to rest on fan bladesand remove later if disired.

(11) Disconnect ether start tubing from the 90 degree elbow at the bottom of thecanister.

(12) Tag and disconnect ether start wiring at the quick disconnect connector locatednear ether start canister.

(13) Tag and disconnect generator output cables from K1 output power contactor.(14) Tag and disconnect wiring from the bottom of TB3 and T86. (see Figure 1)

2-3 January 15, lgggPage 2 Original

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Figure 1. Bridge Assembly(15) Tag and disconnect the wiring from K48 starter contacter.

(16) Clip all wire ties restraining wiring as required to allow free movement of engine.

(17) Disconnect engine ground cable.

(18) Disconnect and cap fuel pressure and return lines.

C. Engine/Generator Removal: (See Figure 2)

CAUTIONWHEN LIFTING THE ENGINE AND GENERATOR, USE A HOIST WITH

LIFTING CAPABILITY OF AT LEAST 3000 LBS (t361 kg).CAUTION

MAKE SURE THE LIFTING CHAINS ARE POSITIONED TO ALLOW THEENGINE/GENERATOR TO BE LIFTED HORIZONTALLY FROM THE UNIT.

(1) Using a lifting hoist and chains, attaching chains to the front engine lifting eyeletand the generator lifting eye bolt.


2 -3Page 3

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IE9OT4OOSLNlJlcRouND PowER UNIT

WARNINGBEFORE REMOVING THE ENGINE/GENERATOR MOUNTING BOLTS,REMOVE ALL SLACK IN THE LIFT CHAINS. APPLY ENOUGH LIFTING

FORCE TO PREVENT THE GENERATOR FROM SHIFTING BACK ONTOTHE FUEL TANK WHEN THE MOUNTING BOLTS ARE LOOSENED.

(2) Remove front and rear mounting bolts securing engine/generator to the frame.Refer to Section 4-3 for illustration.

(3) Lift engine and generator from unit.

CAUTIONDO NOT PLACE ENGINE/GENERATOR DIRECTLY ONTO GROUND OR

FLAT SURFACE. DAMAGE TO ENGINE OIL PAN WILL RESULT. PLACE AN8112INCH (216mm) WOODEN BLOCK UNDER THE FRONT ENGINE MOUNT

BRACKET AND AT LEAST A 3 INCH (76mm) BLOCK ON EACH SIDE OFTHE GENERATOR, BENEATH THE WELDED GENER,ATOR SUPPORT

BRACES.

4. ENGIN E/GEN ERATOR INSTALLATION

CAUTIONUTILIZE TORQUE VALUES FOR GENERAL ASSEMBLY WHEN INSTALLING

ENGINE/GENERATOR MOUNTING BOLTS AND OTHER ATTACHINGHARDWARE.

2-3Page 4


Figure 2. Engine/Generator Lifting Arrangement

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A. Preparation:

(1) lnstaff front engine mount to engine (if previously removed).(2) Attach the two rear engine mounts to fly wheel housing (if previously removed).(3) Instail generator rifting eye bort to stator housing.(4) Attach a suitable hoist to front engine lifting eyelet and to generator lifting eye bolt.

B. Installation:

CAUTIONBEFORE INSTALLING ENGINE/GENERAIOR, tNSPECT EACH SNUBBERWASHER FoR SERVtcEA_BlLtrv. neFu_c-e i'CCRAEkbd on FouND roBE OTHERWISE DEFECTIVE.

(1) Align engine mounts with snubber washers installed on frame.(2) Install engine mounting bolts and torque,

C. En gin e/generator attachments:

(1) Connect fuel pressure and return lines.(2) Connect remote oil drain line to engine oil pan.(3) Connect engine ground cable.

(4) connect wiring to the bottom of rB3 and rB4, remove tags.(5) connect wiring to K4g starter contactor, remove tags.(6) Connect generator output cabtes to K1 output contactor, remove tags.(7) Connect ether start wiring at the quick disconnector, remove tag.(8) Add wire ties to all loose wiring as required.

(9) Connect ether start tubing at the 90 degree elbow at the bottom of the canister.(10) lnstall fan shroud.

(11) lnstall muffler mounting bracket.

(12) Install exhaust piping from the turbo charger to the muffler.(13) Install exhaust piping from the muffler to exhaust discharge.(14) Install muffler retaining strap.

(15) Connect radiator hoses.

(16) Fill radiator with coolant. (see chapter 2, section 1)

5. GE N ERATOR REMOVAL/I NSTALLATIONJanuary 15, 1999 2_gOriginal page 5

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it90T400sLNI ITGROUND POWER UNIT

The generator may only be removed from the engine after the engine/generator has beenremoved from the unit.

A. Generator Removal:

(1) lnstall l ift ing eye bolt (Figure 2.) into generator stator housing and attach lift chainto eye bolt. Remove all slack in chains to prevent the generator from droppingwhen unbolted from engine.

(2) Remove the generator ventilation screen.

(3) Loosen the internal generator fan (2 bolts).

(4) Slide fan assembly back towards generator to gain access to flex coupling.

(5) Remove 8 bolts that secure the flex coupling to the flywheel.

(6) Uncouple the engine and generator by removing the 12 bolts around the generatorcasing.

(7) Remove fan and coupling from generator. Clean and inspect fan, coupling and allattaching hardware for serviceability prior to installing on new generator.

B. Generator lnstallation :

CAUTIONUTILIZE TORQUE VALUES FOR GENERAL ASSEMBLY WHEN INSTALLING

E N G T N E /c E N E RA To R M O U N T,A|oc*rotls A N D O rH E R A fi A C H T N G

(1) Install generator lifting eye bolt into generator stator housing and attach lifting hoist(Refer to Figure 2).

(2) Position the fan around the flex coupling and loosely install the 2 fan bolts.

(3) Using lifting hoist, align the generator to the engine flywheel housing. Attachgenerator to engine using 12 bolts.

(4) Side the fan assembly toward the generator to gain access to the engine flywheeland flex coupling.

(5) Align the holes in the flex coupling plate with the holes in the flywheel and attachwith 8 bolts.

(6) Slide the fan assembly toward the engine and tighten the 2 bolts already installedin the fan assembly.

(7) Install the generator ventilation screen.

(8) Proceedwith engine/generatorinstallation.

6. COOLING SYSTEM

A. Radiator removal (Refer to illustration Chapter 4-3)2-3Page 6


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I

TBRadiator acces(1) Open s door, remove radiator cap.

(2) Open radiator petcock and drain coolant into container.

(3) After coolant has been completely drained from the engine/radiator, close petcock.

(4) Remove canopy shell to gain access to radiator and engine.

(5) Loosen hose clamps and disconnect both hoses (Top and Bottom) from radiator.

CAUTIONTHE RADTATOR tS HELD lN PLACE BY SrX MOUNTING BOLTS (THREE ONEACH SIDE}. SELECT A SUITABLE HOIST TO SUPPORT RADIATOR WHENREMOVING THE MOUNTING BOLTS. BE CAREFUL NOT TO DAMAGE FAN

BLADES OR SHROUD WHEN REMOVING RADIATOR.

(6) Remove the bar at the bottom of the fan shroud.

(7) Remove the ten bolts holding the fan shroud and allow to rest on the fan blades.

(8) Remove the exhaust piping from the muffler to the exhaust discharge.

(9) Remove the overflow bottle.

(10) Remove six bolts, three on each side, and carefully pull the radiator straightupward.

B. Radiator installation (Refer to illustration Chapter 4-3):

(1) Select a suitable hoist to lift radiator.

(2) Carefully position radiator between the two vertical braces.

(3) Secure Radiator into position using six bolts, lock washers and flat washers.

(4) Attach hoses to radiator (Top and Bottom), position and tighten both hose clamps.

(5) Install over flow bottle.

(6) Reposition shroud and refasten using 10 bolts, lock washers and flat washers.

(7) Install exhaust piping from muffler to exhaust discharge.

(8) Install canopy shell.

(9) Ensure radiator petcock is closed. Fill radiator will coolant. (see Chapter 2, Section1)

7. ENGINE OIL CHANGE

A. Change the full-flow (spin-on) filter each time the oil is changed.

NOTE: lf lubricating oil is drained immediately after the unit has been to operatingtemperature, most of the sediment will be in suspension and will drain readily.


2-3Page 7

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r-t90T400sLNTIIGROUND POWER UNIT

(1) Provide a container for catching used oil. Capacity should be greater than 5gal lons.

(2) Remove the drain plug and allow oil to drain completely.

(3) Change the oil fi lter cartridge.

(a) Unscrew the spin-on filter from the filter head; discard the filter.

(b) Apply a light even coat of lubricating oil to the gasket sealing surface of thenew filter prior to installing.

(c) Position the filter to the filter head. Tighten by hand until the seal contacts thefilter head; tighten an additional one half turn.

(4) Clean the drain plug and install securely after engine oil has drained completely.

(5) Remove oil filler cap, or valve cover cap (Refer to engine manual, Chapter 5) andrefill the system with new clean oilwhich meets engine manufacturer'srecommendations (See Chapter 2-1, Table 1).

(6) Installfi l ler cap and check oil level on dipstick. lt should indicate over-full untiltheengine is started and oil is circulated to fill the oilfilter(s).

8. AIR CLEANER

The air cleaner is a replaceable element type. A definite time schedule for changing the filtercartridge cannot be determined because of varying operating and environmental conditions.To change the cartridge, perform the following (see Figure 3):. Unscrew the wingnut.. Remove cover and second wingnut.. Remove and discard cartridge.. Install new cartridge.. Replace wingnut and cover.

2-3Page 8


Figure 3. Air Gleaner Filter

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iHe0T400sLNI . IJGROUND POWER UNIT

CHAPTER2

SECTION4

ADJUSTMENTS AND TEST

1. MAINTENANCE/REPAIR ELECTRONIC BOX ASSEMBLY

A. Disassembly:

The removal of the electronic box under normal situations should never be required.The design allows total access to each component that could require replacement withinthe Electronic Box Assembly.

B. Gaining Access:

There are two levels of access within the electronic box. The primary area for mostcommonly adjusted items is the Back Panel and the PCB Panel, both accessed via stepone (1) below. Then for items that require replacement or adjustment less commonly isthe inside of the Control Panel Face Plate accessed via step two (2) below.(1) Back Panel and PCB Panel Access:

Turn the four (4) thumb scew latches counter-clockwise. Then slowly pull the panelforward until retaining cable is supporting the weight of the panel.To close reverse these steps turning the thumb screws clockwise.

(2). Control Panel Face Plate Access:Remove the six (6) scews that are on the face plate. DO NOT remove the three (3)nuts located on the bottom of the panel (these hold the face plate to the hinge).Pull the control panelface plate forward slowly until the retaining strap supports theweight of the face plate.

2. SYSTEM FAULT TEST PROCEDURESA Test Panelwith 5 test push-buttons (located on the right side of the PCB Panel) is provided tocheck the AC protective circuits and the DC protective circuit if applicable. See Figure 2.. The AC Test push-button switches are:

" UNDER-VOLTS" OVER.VOLTS. UNDER-FREQUENCY. OVER.FREQUENCY" OVERLOAD

CAUTIONDO NOT PERFORM FAULT CIRCUIT CARD TEST WHILE UNIT IS

OPERATING UNDER LOAD.


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==t90T400sLNlJlcRouND PowER uNlr

Figure 1. Electronic Box, PGB Panel.

d-lllflt-FrEtr=ff.' ll *'11 *'oll *'ll

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2-4Page 2


35 PCB PANEL

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Figure 1A. Electronic Box, Back Panel.

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stl R5 s6 s4o

CONTROL PANEL . OPEN, PCB PANEL . CLOSEO, VIBMNG UNDER SIDE PCB PANELPanel Face Plate 071497Re.wmf

Figure f B. Electronic Box, PCB Panel Under Side.

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2-4Page 3

Figure 2. Fault Push-button Test Panel

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A. Protective System Test Procedures(1) AC Overload Test:

* Push and hold the Overload Test switch.* The Overload fault indicator will i l luminate.* The Frequency meter will move to the extreme left.t AC Voltmeter will indicate approximately 10 Volts.

(2) AC Over Frequency Test:* Push and hold the Over Frequency Test switch.

NOTE: Circuit may take up to 5 seconds to actuate.* Frequency and Voltage meters should continue to indicate 4OO Hz and 1 15 VAC

Line-to-Neutral (200 VAC Line-to-Line) respectively.* Over Frequency Fault indicator should il luminate.

(3) AC Under Frequency Test:* Push and hold the Under Frequency Test switch.

NOTE: Circuit may take up to .5 seconds to actuate.* Frequency and Voltage meters should continue to indicate 4OO Hz and 115 VAC

Line-to-Neutral (200 VAC Line-to-Line) respectively.+ The Under Frequency Fault indicator should il luminate.

(4) AC Over Voltage Test:* Push and hold the Over Voltage Test switch.

NOTE: Circuit may take up to 5 seconds to actuate.* Frequency meter will move to the extreme left.* Voltage meter will indicate approximately 10 volts (residual magnetism).* Over Voltage Fault indicator will i l luminate.

(5) AC Under Voltages Test:* Push and hold the Under Voltage Test switch.* Frequency and voltage meters should indicate 4OO Hz and 115 VAC Line-to-

Neutral (200 VAC Line-to-Line) respectively.* the Under Voltage indicator will illuminate at 100VAC after 5-7 second delay.

B. Fault Lamp Test:(1) With Engine Not Operating:

The fault lamps may be tested when the unit is either operating at run speed orwith the engine stopped.(a.) Place the lgnition switch to ON, then place IDLE/RUN switch to RUN position.(b ) Press the Fault Lamp Test switch and observe that allfault indicators illumi-nate red.

- (c.)Release Fault Lamp Test switch; all indicators should turn off.(2) \Mth Engine Operating:

2-4 January 15, 1999Page 4 Original

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Figure 3. Automatic Voltage Regulator (AVR) Module.


2-4Page 5

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Figure 4. AC Overload Module.

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iE90T400sLNI I IGROUND POWER UNIT

(a.) Place the IDLE/RUN switch to the RUN position.(b ) Press the Fault Lamp Test switch and observe that all the fault indicators

illuminate red.(c) Release Fault Lamp Test switch; all indicators should turn off.

C. Testing Engine Fault Indicators Only:o Place lgnition switch to ON. Ensure the IDLE/RUN switch is in the IDLE position.o Press the Fault Lamp Test switch. Only the engine fault indicators will i l luminate.

3. CIRCUIT CARD ADJUSTMENTSAll circuit cards are preset at the factory. In most instances adjustments will not be necessaryafter installation of the circuit card. lf, after installation, fine tuning of the circuit card is neces-sary to obtain optimum performance, follow procedures listed for each circuit card.

NOTE: Units with a line-to-line voltage selector switch will read a normal output voltage to 200VAC. Units with a line-to-neutral voltage selector switch will read a normal outputvoltage of 1 15 VAC. Both line-to-line and line-to-neutral voltages are given the thefollowing instructions.

2-4Page 6


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Figure 5. Over/Under Voltage Module.

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i.H90T400sLNILIGRoUND PoWER UNIT

A. Automatic Voltage Regulator (AVR) modute (See Figure 3):(1) Pull out the Electrical Drawer Assembly to the maintenance position to have

access to the required adjustments (Figure 1).(2) Start unit in accordance with normal start procedures.(3) Place RUN/IDLE switch to the RUN position.(4) The voltage adjustment potentiometer (R5) is located at the rear of the electrical

drawer assembly (Figure 1). Adjust the potentiometer to mid range betweenminimum and maximum settings.

(5) Adjust R32 on the AVR board obtain 200 VAC line-to-line (115 VAC Line-to-Neutral). Counterclockwise rotation (R32) increases voltage.

B. AC Overload Module (See Figure 4\:(1) Start unit in accordance with normal start procedures.(2) Place RUN/IDLE switch to the RUN position and verify 200 VAC Line{o-Line on

the voltmeter (115 VAC Line-to-Neutral).(3) Check test point "A" for 24VDC.

NOTE: Use P1 pin 7 as the test point reference ground for the voltmeter.(4) Place voltmeter at Test Point "B" and measure for 15 VDC t'2 volts.

NOTE: lf 15 VDC t 2 volts is not present, replace circuit card.(5) Place voltmeter at Test Point'C" and adjust R13 to obtain I VDC.(6) R9 and R7 are factory set at fully clockwise, and should be left in that position.(7) Place voltmeter at Test Point "D" and adjust R4 to obtain .85 VDC.(8) Apply a 125% load to unit. Overload fault protection should activate between 3 to 5

minutes.

G. Over/Undervoltage Module (See Figure 5):(1) Start unit in accordance with normal start procedures.(2) Place RUN/IDLE switch to the RUN position and verify 200 VAC Line-to-Line (115

VAC Line-to-Neutral)on the voltmeter.NOTE: Use P1 pin 5 as the test point reference ground for the voltmeter.

(3) Place voltmeter at Test Point (TP) A and measure for 24VDC * 2 VDC.NOTE: lf 24VDC t 2 VDC is not present, Check the power supply module.

(4) Place voltmeter at TPB and measure for 15 VDC t 2 volts.NOTE: lf 15 VDC t 2 volts is not present, Replace circuit card.

(5) Adjust R32 on voltage Regulator circuit card to obtain 155 VAC line-to-line (87.5VAC Line-to-Neutral) indication on instrument panel voltmeter.

(6) Measure voltage atTPZ on the circuit card and record the voltage reading.(7) Place voltmeter at TP3. Adjust R10 to obtain the same voltage as TP2 (step "f').

January 15, 1999 2-4Original Page 7

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Figure 6. Over/Under Frequency Module.

(8) Adjust R32 on the Voltage Regulator Circuit card to obtain 200 VAC line{o-line(1 15 VAC Line-to-Neutral) indication on the GPU voltmeter.

(9) Clear faults by pressing fault reset switch (511).(10) Adjust R32 on the voltage regulator circuit card to obtain 225VAC line-to-line (130

VAC Line-to-Neutral) indication reading on the GPU voltmeter.(11) Measure voltage at TP2.(12) Place voltmeter at TP1. Adjust R9 to obtain the same voltage as TP2 in step (11).

NOTE: Because the over-voltage condition will cause the voltage regulator to shut off, it maybe necessary to press the fault switch 511 during the adjustment procedure.

(13) Adjust R32 on the voltage regulator circuit card to obtain 200 VAC line-to-line (1 15VAC Line-to-Neutral) on the GPU voltmeter.

D. Over/Under Frequency Module (See Figure 6):(1) Start unit in accordance with normal start procedures.

2-4Page 8

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i.F|eoT400sLNLJ-IGROUND pOWER UNIT

(2) Place RUN/IDLE switch to the RUN position and verify 200 VAC line-to-line (115VAC Line-to-Neutral) on the GPU voltmeter and 400 Hz on the GPU frequencymeter. Adjust if necessary.

NOTE: Use P1 pin 5 as the test point reference ground for the voltmeter.(3) Place voltmeter at Test Point "A" and measure for 24 VDC t 2 volts.

NOTE: af 24VDC t 2 volts is not present, check power supply module.(4) Place voltmeter at Test Point 1 (TP1) and adjust R12 to obtain 3 VDC.

(5) Adjust governor control speed adjustment to obtain 380 Hz indication on the GPUfrequency meter.

(6) Place voltmeter at Test Point 3 (TP3) and measure for 2.89 VDC. Adjust R6 ifnecessary to obtain conect measurement.

(7) Adjust governor control speed adjustment to obtain 4OO Hz indication on GPUfrequency meter.

(8) Clear fault by pressing Fault reset switch 511 on the GPU instrument panel.

(9) Adjust governor control speed adjustment to obtain 42O Hz indication on GPUfrequency meter.

(10) Place voltmeter at Test Point 2 (TPz) and measure for 3.11 VDC. Adjust R7 ifnecessary.

(11) Adjust governor control speed adjustment to obtain 4QO Hz.

(12) Clear faults by pressing Fault Reset switch (S11) on the GPU instrument panel.


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-t90T400sLNIIIGROUND POWER UNIT

4. ELECTRONIC GOVERNOR ADJUSTMENTS

WARNINGTO PROTECT AGAINST POSSIBLE PERSONAL INJURY, LOSS OF LIFE, AND/OR

PROPERW DAMAGE WHEN STARTING THE ENGINE, BE PREPARED TO MAKE ANEMERGENCY SHUTDOWN TO PROTECT AGAINST OVERSPEED SHOULD A

COMPONENT OF THE GOVERNOR OR ENGINE SPEED CONTROL SYSTEM FAIL.

A. Governors America Corporation (GAC) unit:(1) Magnetic Pickup: \Mth engine stopped, adjust magnetic pick-up (Figure 9) to

between .020 inches (0.45 mm) from flywheel ring teeth, Usually, backing out thespeed sensor 3/4 turn after touching the ring gear teeth will achieve a satisfactoryair gap. The magnetic pickup voltage should be at least 1 VAC RMS duringcranking.

(2) Electronic Governor (EG), (See Figure 7,8,10):* Adjust all potentiometers on the EG to center position.* Start engine. As engine cranks, the actuator should move to the maximum fuel

position until the engine fires. The governor should control the engine at low idlespeed.

* lf the engine is unstable after starting, turn the GAIN and STABILITY adjustmentpotentiometers counterclockwise until the engine is stable.

* Set IDLE/RUN switch on engine panelto RUN. Adjustgovernorspeed to 2000 RPMif using Marathon@ generator or 24OO RPM if using Kato@ generator by turning theSPEED adjustment CLOCKWISE to INCREASE engine RPM, orCOUNTERCLOCKWISE to DECREASE engine RPM.

2-4Page 10


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Figure 7. GAC Electronic Governor Control.

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Figure 8. Governor Linkage.

MAGNETIC PICKUP

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Figure 9. GovernorSystem Magnetic Pickup.


2-4Page 1 1

i I',IAX[,IUM FIJEL\-,-rPosmoN

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cLoo<'\MsE(JnrTLhISTAEI.JTY OEVE

STEP I. WITH (AIT AT BUN' SPEEO. ADIJSTSPEEO CONTROL TO OESIFEO ENGO,IE OPERATII{GSPEED BY AOJUSTING UNNL CONTROL PANELGENEMTOR FIIEoUENCY lvtETER READS400 tt (24{D RPM).

cLocrws€INSTASIUTY

@(A|TER€.OO(|^/ISEWNL STAOUTYFENNNST}€NADO INTURI{

IIEP-I. MOVE C€NTFOL s,vlTcH TO lotEPOSrnSN. ADJUST totE SPEEO @NTROL crocrwtse notmoNToPhoPERSETTING'

- Tott{ceEAriEDtEspEED

STEP 5. USN6 T}€ ENGS€ SP€ED ADI/ST]i,GNT(STEP r) |l{CnEAsE EM|N€ SPEED TO A FFEOUENCTFEAOhIC OF !O II ON THE GENEFATOF @NTROLPAI€L. FOTATE TI'€ OVERSPEEO ADJUST SCNEWCOUNTEFCLOCIOVTIE UNTL LED UGHTS. ENONEWIII S} TT.OOU/II. PRESS FESET OUTTON. IfNADJIFT SP€EO ADIJST ONE FJlr TIJRNCOUNTEFCLOCIOIISE To AIIot'V Etlcll.lE RESTART.

EEE9. NESTAAT UI{TAAD REP€AT STEP 1,ADJUSTI{G IJiITRUN SPEED TOTHE SPEOFEDRPM. THE GOVERNOR U/t! NOW R'NCTIICNPROPEFLY FOR IOI€. RUN. A'.ID THE PROP€ROVERSPEED SHUTOOWN,

2-4Page 12


Figure 10. GAC Control Unit Adjustments.

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iEeoT400sLNl- l-IGROUND pOWER UNITWith engine at 2000 RPM if using Marathon@ generator or 24OO RPM if using aKato@ generator and NO LOAD, rotate the GAIN adjustment until instabilitydevelops. Gradually move the adjustment counterclockwise until stability returns.Move the adjustment one division further counterclockwise to insure stableperformance.\Mth engine at2000 Rpm if using Marathon@generatoror2400 RPM if using Kato@generator and NO LOAD, rotate the STABILIry adjustment clockwise untilinstability develops. Gradually move the adjustment counterclockwise untilstabilityreturns. Move the adjustment one division further counterclockwise to insure stableperformance.

NOTE: Gain and stability adjustments may require minor changes after engine load is applied.Normally, adjustments made at no load achieve satisfactory performance. lf instabilitycannot be corrected and further performance improvements are required, refer toTroubleshooting section.

" After the governor speed setting has been adjusted, place the IDLE/RUN switch to"IDLE' position. The IDLE speed set point is INCREASED by CLOCI(VVISE rotationof the IDLE adjustment control. Adjust idle speed to 800 RPM.

(3) Overspeed Adjustment (See Figure 7,10): The electronic governor performs overspeed sensing and will shut down the engine should RPM exceed approximately2650. Adjustment for overspeed is located on the electronic governor.

Start unit in in accordance with normal starting procedures.Set IDLE/RUN switch to RUN.Rotate SPEED adjustment potentiometer clockwise until engine speed reaches2650 RPM or engine speed no longer increases.Rotate OVERSPEED adjustment counterclockwise until engine shuts down. TheOVERSPEED indicators located on the Electronic Governor module (Upper leftcorner) and the indicator on the control panel will illuminate. Rotate OVERSPEEDadjustment clockwise one half turn. The overspeed circuit is now adjusted.Reset the governor by pressing the RESET push-button located on the ElectronicGovernor. The Overspeed indicator on the Electronic Governor and the indicator onthe control panelwill go out.Rotate the speed potentiometer counterclockwise one turn to prevent the enginefrom reaching overspeed RPM the next time the engine is started.Start the engine, set the IDLE/RUN switch to RUN then adjust engine speed downto 2000 RPM if using Marathon@ generator or2400 RPM if using Kato@ generator.

(4) Governor Linkage Installation and Adjustment (See Figure 8):Move the actuator leverforward and rearward to assure freedom and proper travel.Attach governor linkage to both the actuator lever and to the fuel control rod.Hold fuelcontrol leverto MIN position and adjust the actuator leverto vertical or 118inch clockwise.Move linkage back and forth to assure fullfueltravel and that there are no points ofbinding.


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-t90T400sLNlltcRouND PowER uNlr* Additional adjustments to the electronic governor may be required to ensure

satisfactory operation under load. Adjust the electronic governor as required

(Gain/StabilitY).

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1.

tr GRouND powER uNrrCHAPTER

2SECTION

5

CLEANING AND PAINTING

CLEANINGCleanliness of the unit not only adds to the general appearance, but it is also a factor inreducing the maintenance upkeep. A unit maintained with periodic cleaning will require lessrepainting and will also help prevent the accumulations of abrasive grit on moving partsand surfaces. Cleaning schedules should be devised by the user according to hisenvironmental and operating conditions. Painted surfaces require washing with a milddetergent and rinsing with clean water. A bristle brush (never wire) or spray gun may beused. Unpainted surfaces are cleaned using plain water and brush, approved solvents, orsteam cleaning equipment. Degreasers may be used to remove grease accumulationsfrom non-lubricated metal parts. Care should be taken with degreasers, as some brandswill also remove or damage painted surfaces. Clean electrical parts with a lint-free cloth,moistened with approved solvents for electrical equipment.

CAUTIONDO NOT ALLOW SOAKING, SPRAYING OR STEAM CLEANING TO AFFECT

ELECTRICAL COMPONENTS OR WIRING. RUBBER COMPONENTSSHOULD NOT BE CLEANED WITH SOLUTIONS HAVING A PETROLEUM

BASE SUCH AS KEROSENE, MINERAL SPIRITS, STODDARD SOLVENT ORDRY CLEANING SOLVENTS.

PAINTINGPainted surfaces, in addition to presenting a good appearance, etc., protect the unit fromdeterioration. Paint should be maintained on a non-scheduled, as required, basis.Depending on environmental and operational conditions, repaint the entire unit whenever itbecomes necessary. The unit is painted to user specifications and will be repainted at theirmaintenance facil it ies.

2.

July 10, 1997Original

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CHAPTER3

OVERHAUL/MAJOR REPAIR

1. GENERALUnder normal operating conditions and proper preventive maintenance, the GPU should provideexcellent service for a period of 20,000 to 30,000 hours (depending on local conditions) beforeconsiderations should be given to major component repair or overhaul.

Overhaul or major repair of the GPU power plant, i.e., the Cummins engine, should beaccomplished in accordance with the maintenance/overhaul recommendations of Cummins ortheir authorized agents.

The Kato generator will normally require no overhaul other than normal maintenance or repairprocedures. lf a rebuild is found to be advisable, Kato should be contacted for their recommen-dations and or procedures.

The Trilectron built and mounted equipment requires no scheduled overhaul. Normal mainte-nance and repair of the unit and subsystems will maintain the equipment in properworking order.


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Property of American Airlines Maintenance · Add oil as necessary. NOTE: Change oil and filter after first 50 hours of operation, then every 250 hours of operation or every six months,