The M284 removable sensor assembly has a diagnostic packagethat includes Adaptive Electronics and a Fault-Check output. Withthis package, the SMARTach can maintain itself, and let you knowif there is a problem before the problem causes unscheduleddowntime. Certain models automatically switch to back-up sensorsif a problem occurs. See MAINTENANCE Section III (page 6) formore details.

SECTION II: INSTALLATION

GENERAL

Proper installation of an M285 Encoder requires ROTORINSTALLATION, STATOR HOUSING INSTALLATION (the outercase of the encoder), SENSOR ASSEMBLY INSTALLATION,and completion of the GAPPING SEQUENCE. Also included inthis section are unpacking directions, wiring instructions, and out-line and mounting dimension drawings. The motor must complywith 1987 NEMA MG1-11.68 for dimensions, face runout, andshaft runout. Axial float or endplay must be less than ±0.050 inch.See Mechanical Specifications.

SECTION I: DESCRIPTIONGENERALThe Avtron Model M285 SMARTach™ (patents #5,502,376,#5,608,277, and #5,545,985) is an incremental encoder (also knownas tachometer or rotary pulse generator), allowing operation down tozero RPM. It provides a specific number of electrical Pulses PerRevolution (PPR) that are proportional to a shaft’s revolution. TheM285 SMARTach is a bearingless, couplingless, modular design,providing unequaled reliability, and mechanical performance.

The M285 fits AC and DC motors with an 8.5" C (FC / 180) Face.Both end-of-shaft and through shaft mountings are accommodated.

The M285 Encoder consists of three parts: a rotor, a stator housing,and removable sensor module. These precision machined partsmount to the accessory end of a motor that conforms to 1987 NEMAMG 1-11.68 for Type FC Face Mounting. See MechanicalSpecifications (page 2). After mounting, a simple, no-measurementgapping sequence precisely sets the sensor-rotor gap to factoryspecifications.

An Avtron M285 SMARTach is equipped with one or two M284sensor modules. Eachmodule has a two-phase output (A,B) 90° outof phase, with complements (A

–,B–), (A Quad B Output). A marker

pulse with complement (Z,Z–) is available as an option. An optional 4-

output housing is available.

Output resolution is determined by the rotor’s base PPR (pulses perrevolution), times an M284 sensor multiplier. The M284 sensormodule can provide: the base PPR, 1/2 the base PPR, or doublethe base PPR (see table 1-1).With two sensor modules, the sameencoder can provide two different PPRs from a given rotor at thesame time.Only one rotor per M285 is possible. Sensors and rotorsare not interchangeable between M285 units with different basePPRs.

8 9 0 1 E . P L E A S A N T VA L L E Y R O A D

I N D E P E N D E N C E , O H I O 4 4 1 3 1 - 5 5 0 8

T E L E P H O N E : ( 1 ) 2 1 6 - 6 4 2 - 1 2 3 0 • FA X : ( 1 ) 2 1 6 - 6 4 2 - 6 0 3 7

E - M A I L : t a c h s @ a v t r o n . c o m • W E B : w w w. a v t r o n e n c o d e r s . c o m

EncoderManual

M285SMARTach™

AVAILABLE RESOLUTIONS-48 OPTION480 PPR Rotor

-51 OPTION512 PPR Rotor

-60 OPTION600 PPR Rotor

LOW 240 256 300

MEDIUM 480 512 600

HIGH 960 1024 1200

ModelBasePPR

Left Module Right Module

Marker Range (PPR) Connector Volts Marker Range Connector VoltsM285M285L*M284M284L*

48- 48051- 51260- 600

Z- Marker- None

L- Low Range(Base PPR x 1/2)

M- Medium Range(Base PPR x 1)

H- High Range(Base PPR x 2)

N- Wire Leads OnlyC- 10 Pin MS w/ PlugL- 10 Pin MS Elbow w/ PlugR- Small MS Bulk HeadT- Terminal BoxK- ConduletP- Plug-in IndustrialG- Plug-in Industrial (Northstar pinout)Z- Plug-in Industrial 3' Flex. CableE- 5 Pin MS w/o Plug (M737 equiv.)F- 5 Pin MS w/ Plug (M737 equiv.)H- 5 Pin MS w/o Plug (M727 equiv.)J- 5 Pin MS w/ Plug (M727 equiv.)

1- 12-15V2- 12-15V,

Quad.3- 5-18V5- 5-24V

M285/M285L: Same Code Formatas Left Module

M284/M284L: Not Applicable

* M285L/M284L - Integral LED Alarm Indicator

The removable sensor assemblies included with Model M285Encoders are identified by model number M284. A sensorassembly consists of a sensor module and a connector option.

Rotors, through-shaft cover plates, and shaft grounding kits areordered separately. (See tables on page 5)

M285 PART NUMBERS AND AVAILABLE OPTIONS (including M284 sensors Add rotor # from table 3-1 or 3-2)

8 1/2" FC FACE MOUNTMODULAR

TABLE 1-1

INSTALLATION HARDWARE

Installation hardware required is attached to each assembly.

Equipment needed for installationSupplied:M285 Encoder1. Washer, Spring Lock 1/2 (4)2. Hex Hd. Cap Screw 1/2-13 x 3.00 (4)

Rotor1. Rotor Installation Hardware Kit2. Anti-Seize Compound (copper)3. Thread Locker (blue)

Not Supplied:3/4" Wrench Phillips Screwdriver7/16" Nut Driver Dial IndicatorVernier Caliper3/32" Hex Wrench (T-Handle style) (thru shaft rotors only)9/16" Wrench (end-of-shaft rotors only)

Optional:Rotor Gauge Block (thru shaft rotor only)Inboard Through-Shaft Seal PlateOutboard Through-Shaft Seal Plate KitSilicone Lubricant or 20 Weight Machine Oil

ROTOR INSTALLATION

CAUTIONThe outer edge of the rotor may bedamaged by scratches, severeblows, and strong magnetic fields.

Apply anti-seize compound to the shaft.

END-OF-SHAFT APPLICATIONS: Verify thatthe shaft projection from the accessorymounting face of the motor is 0.400 ±0.050"including axial endplay.The B23490-1, -31, and-61 rotors use a roll pin to prevent rotation ofthe rotor on the shaft. Install the pin in the rotorfirst, then position the rotor on the shaft. Lightlytap into place. Install the center bolt, applythread locker, flat washer, and springlockwasher and tighten.

THROUGH SHAFT APPLICATIONS: Thethrough-shaft must project at least 1.2" fromthe accessory mounting face. If it is greaterthan 2" long, use the outboard through-shaftcover, detailed below. Slide the rotor on theshaft with the set screw hub nearer the motorface. The space between the mounting faceand the side of the rotor must be set to 0.584",as shown in the Figure 2-1. (Note: if optional

inboard seal plate is used, the space must be set to 0.620" per theinstructions below)

(OPTIONAL) INBOARD SEAL PLATE INSTALLATION:

For installations where the M285 will be mounted to an open frameflange adapter, or other installation where the inner surface of theM285 will not form a seal with the rear end bell of the motor, Avtronoffers an inboard, through-shaft seal plate kit. This kit includes acover plate, and seal. See table 3-4 for part numbers.To install theinboard through-shaft seal plate kit:

1. Verify all components fit the motor shaft (rotor, V-ring seal, andseal plate.

2. Slide V-ring seal onto motor shaft.

MECHANICAL SPECIFICATIONS

Features and specification subject to change without notice.

SPEED RANGE 0-4500 RPM for base PPR of 480

SPEED RANGE 0-4200 RPM for base PPR of 512

SPEED RANGE 0-3600 RPM for base PPR of 600

OPERATING TEMP. -20°C to 80°C

MOUNTINGREQUIREMENTS

8.5" pilot per NEMA MG1-11.68 type FC accessory mounting face.Exception: The M285 can tolerate non-standard pilot eccentricity upto 0.040" FIM; Max. Runout over installed Rotor 0.006" FIM; ShaftAxial End Play ±0.050".

WEIGHT 9 lbs.

CAUTIONDo not strike the encoder or rotor at any time.Damage will result and the warranty will be void. Atinstallation, clean and remove paint and burrs frommotor shaft and mounting face. Apply anti-seizecompound (supplied) to each.

UNPACKING INSTRUCTIONS

The M285 is supplied as three main components: 1) the magnet-ized rotor with the specified base PPR and shaft mountingconfiguration, 2) the stator housing with the specific connectoroptions installed, and 3) the sensor assembly(s). Check name-plate and verify all components received as ordered. Check forexternal damage or missing items. This must be handled by thecustomer through the shipper.

2

ELECTRICAL SPECIFICATIONS

* (Not available on wiring option “G”, Northstar compatible pinout.)

LINE DRIVER/VOLTAGE INPUT OPTIONS

1 3 5

INPUT VOLTAGE (+V) 11.5 - 15.5V 4.8 - 18V 4.8 - 26V

LINE DRIVER 4428 4428 7272

START-UP CURRENT NO LOAD 80mA 300mA 300mA

OPERATING CURRENT NO LOAD 80mA235mA@5V90mA@12V

235mA@5V90mA@12V60mA@24V

DIFFERENTIALSQUARE WAVE OUT-PUTA leads B for CW rota-tion, anti drive end view

VOH

((+V)-1.8V) min.@50mA avg.

((+V) -1V) min.@50mA avg.

((+V) -2.3V) typ.@20mA avg.

IOH

(Source) 80mA avg. max., 1.5A peak 80mA avg. max.

VOL

0.6V max.@5V, 0.4V max.@12V @50mA avg.

0.5V max.@20mA avg.

IOL

(Sink) 80mA avg. max., 1.5A peak 80mA avg. max.

MAXIMUM CABLE DRIVE (feet) 20001000@5V in.500@12V in.200@24V in.

PROTECTION

Reverse Voltage Yes Yes

Transient Yes Yes

Short Circuit No Yes

MARKEROnce per revolution. Pulse width approx.1/3 of base PPR period.

ALARMRefer tofigure 2-5 (p. 8)

+V (OUT)50mA max.

This is a convenience output, internally jumpered to +V operating voltage.It is intended for alarm circuits like solid state relays that can be refer-enced to +V. *

ALARMOpen collector, sink 100mA max, withstand 50V max from common.Output goes low on alarm. *

LEDINTEGRAL LED INDICATORGREEN - Power OnRED - Alarm On

HOUSINGSTATOR

ROTOR

FACE

SETSCREWHUB

MOUNTINGACCESSORY

SEAL PLATE

MOTOR

ALL ROTOR TYPES)ENDPLAY (TYPICAL-INCLUDING AXIAL

0.620 ±0.050"

V-RINGSEAL

MOTOR SHAFT

OPTIONAL OUTBOARDSEAL PLATE

3. Apply a light coating of silicone lubricant or medium grademachine oil to the outward face of the seal.

4. Use the seal plate to push the seal on the shaft; stop when theseal plate contacts the motor face. Remove the seal plate andpush the V-ring seal an additional 0.09" toward motor. Verify the V-ring seal is clear of the motor bearings and housing. V-ring sealcompression should be between 0.03" and 0.09" in final positionwhen plate is reapplied.

5. Reapply inner cover plate.

6. Mount rotor per instructions below, but increase axial positionfrom motor to rotor to 0.620" (from 0.584") to accommodate theinner seal plate thickness. See figure 2-2 (from drawing A26211,sheet 3).

7. Mount remainder of M285 per instructions below, orienting thebolt holes in the inner seal plate with the M285 stator housing.

STATOR HOUSING INSTALLATION

CAUTIONWhen the M285 stator housing is to be removed orinstalled, the M284 sensor assemblies MUST FIRSTbe removed from the stator housing.

The stator housing is retained to themotor using four, 1/2-13 x 3-1/4"bolts and spring type lock washers (supplied). See tables (page 5)for installation hardware kit part numbers, available separately. If thestator is to be sandwich mounted between an accessory such as abrake and the motor, select the bolt length accordingly. Carefullymove the stator housing into position, avoiding contact with the rotor.Install the four mounting bolts (torque 30 to 35 foot pounds).

If the encoder will be exposed to water spray, the bottom 1/8" pipeplug should be removed to provide a drainage path.

CAUTIONDO NOT use silicone sealants or caulk of any kindon the motor or encoder face; these can causemisalignment or sensor scraping damage. TheM285 electronics are fully sealed; water may enterand leave the rotor area as needed. A drain holeoption is available if frequent moisture buildup isexpected.

(OPTIONAL) OUTBOARD SEAL PLATE KIT INSTALLATION.

For applications requiring shafts to pass completely through theM285, such as brake sandwich applications, Avtron offers anoutboard through-shaft seal plate kit with V-ring seal. See table3-4 for part numbers and (figure 2-3).

To install the outboard through-shaft kit:

1. Install the encoder rotor as shown above in the standardposition from the motor face.

2. Remove the existing solid rear cover of the encoder. Retain the(4) #10-24 screws and washers.

3. Mount the M285 stator housing as shown above.

4. Install new through-shaft cover using the (4) #10-24 screws andwashers from step 2.

5. Apply silicone lubricant or medium grade machine oil (20weight) to the outboard side of the cover where the V-ring seal willcontact it.

6. Slide the V-ring seal onto the shaft, and ensure that it iscompressed against the cover. See installation figure 2-3

7. Install M284 sensors as shown and follow the gappingsequence shown below.

SET SCREW HUB

ACCESSORY MOUNTING FACE

0.584 +/−0.050" INCLUDING AXIAL ENDPLAY (Typical − All Rotor Types)

MOTOR

ROTOR MOUNTING(Through Shaft Shown)

FIGURE 2-1 3

HOUSINGSTATOR

ROTOR

FACE

SETSCREW

HUB

MOUNTINGACCESSORY

SEAL PLATE

MOTOR

ALL ROTOR TYPES)ENDPLAY (TYPICAL-INCLUDING AXIAL

0.620 ±0.050"

V-RINGSEAL

MOTOR SHAFT

OPTIONAL INBOARDSEAL PLATE

FIGURE 2-2 FIGURE 2-3

(OPTIONAL) SHAFT GROUNDING KIT INSTALLATION

Refer to separate Shaft Grounding Kit Instructions (M190-M285)

SENSOR ASSEMBLY INSTALLATION

Before an M284 sensor assembly is installed in a stator housing, itmust be in the retracted position (as shipped). If the sensor waspreviously used the READJUSTMENT SEQUENCE, given inSection III (page 7), must first be done. Always do the readjustmentsequence if there is any question.

1.) Ensure that mating surfaces are clean and free of paint, burrs, etc.

2.) Ensure the rotor is stationary. Carefully position the sensorassembly in the stator housing, using the rounded corner of themounting surface to correctly orient the sensor. Use caution not todamage sensor face.

3.) Install the four #8-32 x 1" mounting screws, flat washers, andlock washers provided. The sensor-rotor gap must now be set byfollowing the GAPPING SEQUENCE.

GAPPING SEQUENCE

Follow the instructions as shown below in the M285 GappingSequence. See figure 2-4. If regapping is required, conduct theREADJUSTMENT SEQUENCE in Section III (page 6) first.

CAUTIONSequence must be followed properly or damage tothe sensor and the rotor will result.

CAUTIONDO NOT replace pin into the slotted hole or damagewill result.

WIRING INSTRUCTIONS

Remove power before wiring.

Wiring diagrams are shown in figure 2-6.

For bi-directional operation of the encoder, proper phasing of thetwo output channels is important. Phase A channel leads phase Bchannel for clockwise shaft rotation as viewed from the anti-drive oraccessory end of the motor (encoder mounting end).

Wiring option "G" provides a pinout compatible with Northstarencoders, with a cable shield connection on pin 10. Note that thisoption does not ground the shield; Avtron still recommends

QuickRelease

Pin RubberPlug

Locknut

movementof pin

StorageHole

M285 GAPPING SEQUENCE

1.) Loosen Locknut: [Loosen the locknut until the quickrelease pin moves inward, toward the motor shaft.]

2.) Tighten Locknut: Tighten the locknut. The sensor is nowin contact with the rotor. Remove the rubber plug from storagehole.

3.) Pull Quick Release Pin: Pull the Quick Release Pin fromthe slotted hole. This automatically gaps the sensor. Put therubber plug in the hole. Keep the pin for future use: a storagehole is provided. DO NOT put pin back in the slotted hole.

NOTEA video of the gapping sequence can be viewed on-line at www.avtron.com/m285_airgap.htm

FIGURE 2-4

4

5

ROTOR PART NUMBERS (US shaft sizes, see metric table below)Shaft

GroundingKit

END OF SHAFT APPLICATIONS THROUGH SHAFT APPLICATIONS

SHAFT SIZE 480 PPR 512 PPR 600 PPR 480 PPR 512 PPR 600 PPR

0.6250/0.6245 B23490-10 B23490-40 B23490-70

0.7500/0.7495 B24301-25 B24301-55 B24301-85

0.8750/0.8745 B24301-22 B24301-52 B24301-82

1.0000/0.9995 B23490-9 B23490-39 B23490-69

1.1250/1.1245 B23490-1 B23490-31 B23490-61 B23490-11 B23490-41 B23490-71 A24387

1.3750/1.3745 B23490-12 B23490-42 B23490-72

1.6250/1.6245 B23490-13 B23490-43 B23490-73

1.7500/1.7495 B24301-26 B24301-56 B24301-86

1.8750/1.8745 B23490-14 B23490-44 B23490-74

2.0000/1.9995 B23490-15 B23490-45 B23490-75

2.1250/2.1245 B23490-2 B23490-32 B23490-62 B23490-16 B23490-46 B23490-76 A24388

2.2500/2.2495 B23490-17 B23490-47 B23490-77

2.3750/2.3745 B23490-3 B23490-33 B23490-63 B23490-18 B23490-48 B23490-78 A24389

2.5000/2.4995 B23490-19 B23490-49 B23490-79

2.8750/2.8745 B23490-4 B23490-34 B23490-64 B23490-20 B23490-50 B23490-80 A24390

3.2500/3.2495 B25507-13 B25507-14 B25507-15

3.3750/3.3745 B25507-16 B25507-17 B25507-18

3.5000/3.4995 B25507-1 B25507-2 B25507-3

GECD6000 B23635-1 B23635-2 B23635-3 A24392

30.000/29.987 mm B24301-23 B24301-53 B24301-83

42.000/41.987 mm B24301-27 B24301-57 B24301-87

60.000/59.987 mm B24301-24 B24301-54 B24301-84

80.000/79.970 mm B25507-10 B25507-11 B25507-12

80.030/79.953 mm B25507-7 B25507-8 B25507-9

LARGE FRAME MOTOR ADAPTERS

GECD4300, 4400, 5400, 6400, 6500 GECD4500, 7500, 7600 GECD4600, 4700, 8500, 8600

PPR 480 512 600 480 512 600 480 512 600

Complete Kit A29475-1 A29475-2 A29475-3 A29476-1 A29476-2 A29476-3 A29477-1 A29477-2 A29477-3

Stator Adapter B23689 B23689 B23689 B23690 B23690 B23690 B23690 B23690 B23690

Shaft Adapter B29210 B29210 B29210 B29210 B29210 B29210 B29210 B29210 B29210

Rotor B23490-10 B23490-40 B23490-70 B23490-10 B23490-40 B23490-70 B23490-10 B23490-40 B23490-70

* millimeters

Shaft Grounding A29489 A29489 A29489 A29489 A29489 A29489 A29489 A29489 A29489

TABLE 3-1

TABLE 3-2

grounding the shield at the drive end of the cable for all wiringoptions.

CORRECTIVE ACTION FOR PHASE REVERSAL1) Remove Power.2) Exchange wires on cable, either at encoder

cable end, or at speed controller end (but notboth).

a) Single Ended 2 Phase Wiring(see wiring diagram)Exchange A and B at the use end of the wires.b)Differential 2 Phase Wiring (see wiringdiagram) Exchange either A with A– in thephase A pair OR B with B– in the phase B pairbut NOT both.

3) Apply Power.4) Verify encoder feedback is correct, using hand

rotation of shaft, or jog mode of the speedcontroller.

Interconnecting cables specified in theWIRE SELECTION CHARTin figure 2-6 on page 9 are based on typical applications. Refer tothe system drawing for specific cable requirements whereapplicable.

Physical properties of cable such as abrasion, temperature,tensile strength, solvents, etc., are dictated by the specific

M285 Thru-Shaft Cover Plates with Seals

Outboard Thru-Shaft Cover (5.5") Inboard Thru-Shaft Cover (8.5")

Shaft Size Complete Kit Cover Only Seal Only Complete Kit Cover Only Seal Only

.625" A23291-1 B25038-1 471814 A26211-1 B24565-1 471814

1.000" A23291-2 B25038-2 471900 A26211-2 B24565-2 471900

1.125" A23291-3 B25038-3 471873 A26211-3 B24565-3 471873

1.375" A23291-4 B25038-4 471884 A26211-4 B24565-4 471884

1.625" A23291-5 B25038-5 471901 A26211-5 B24565-5 471901

42mm A23291-16 B25038-24 471901 NA NA NA

1.875" A23291-6 B25038-6 471902 A26211-6 B24565-6 471902

2.000" A23291-7 B25038-7 471886 A26211-7 B24565-7 471886

2.125" A23291-8 B25038-8 471903 A26211-7 B24565-7 471886

2.250" A23291-9 B25038-9 471903 A26211-8 B24565-8 471903

2.375" A23291-10 B25038-10 471904 A26211-8 B24565-8 471903

2.500" A23291-11 B25038-11 471905 A26211-9 B24565-9 471905

2.875" A23291 B25038 471885 A26211-10 B24565-10 471885

80mm A23291-13 B25038-13 471907 NA NA NA

86.85mm A23291-12 B25038-12 471906 NA NA NA

3.500" A23291-14 B25038-14 471907 A26211-11 B24565-11 4719010

6

application. General electrical requirements are: stranded copper,22 thru 16 gauge (Industrial EPIC Connector options can use 14AWG), each wire pair individually shielded with braid or foil withdrain wire, 0.05 uF maximum total mutual or direct capacitance,outer sheath insulator, 1,000 ft. max. See WIRE SELECTIONCHART in figure 2-6 on page 9 for some suggested cables.

NOTEWhen using the plug-in industrial EPIC connector(“G”, “P”, “V”, “X”, or “Z” options), the wire endsmust be tinned with solder before connection at thescrew terminals.

SECTION III: MAINTENANCE

GENERAL

This section describes routine maintenance for the Avtron M285Encoder. Parts lists are also provided. If additional information isrequired regarding service, parts, or repairs, please contactAvtron’s field service department at 216-642-1230. Avtron stan-dard warranty applies. For emergency after hours service contactus at 216-641-8317.

TABLE 3-4

7

The M285 SMARTach circuitry includes a diagnostic packagethat includes Adaptive Electronics and a Fault-Check output (seebelow).

ADAPTIVE ELECTRONICS

A perfect duty cycle consists of a waveform whose “high” and “low”conditions are of the same duration (50%/50%).

It is possible, over time, for duty cycle to change due tocomponent drift, temperature changes, and mechanical wear.The M285 adaptive electronics extends the life of the M285 byconstantly monitoring and correcting duty cycle over time.

FAULT-CHECK

The Fault-Check LED will turn green after power-up andsuccessful self calibration of the Adaptive Electronics. To calibrate,the M284 sensor must be properly installed and gapped, and themotor shaft and rotor must reach at least 100 RPM.

If the Adaptive Electronics reach their adjustment limit for anyreason, the Fault-Check alarm and LED will notify the drive andoperator of an impending failure. The LED will turn red if theAdaptive Electronics reach their adjustment limit, the Fault-Checkalarm and LED will notify the drive and operator of an impendingfailure. This output occurs before an actual failure, allowing stepsto be taken to replace the unit before it causes unscheduleddowntime. Fault-Check annunciation is available as an “alarm”output through the connector or as an optional integral LED.

STATOR HOUSING REMOVAL

CAUTIONBEFORE removing the stator housing, the sensorassemblies MUST be removed from the housing.

M284 SENSOR READJUSTMENT SEQUENCE

Follow this procedure if the sensor is removed and installed inanother encoder, or in another sensor location on the sameencoder, or if the stator has been removed and reinstalled onanother motor.

1.) Remove the sensor assembly from the M285 by removing thefour #8 mounting screws; then carefully pull the assembly out ofthe stator housing.

2.) Loosen the 1/4-20 locknut next to the quick release pin ring.

3.) Place the quick release pin (with ring) all the way into slottedhole.

LIFT WHENINSERTING

SENSOR ASSEMBLY(Inserting the Pin)

SENSOR ASSEMBLY(Compressing the Extension Spring)

FIGURE 3-1 FIGURE 3-2

NOTEThe pin must be fully inserted until it bottoms outagainst the ring. Inserting the pin compresses thegapping spring by moving the plunger a preciseamount (the desired gap). See detail in figure 3-1.Enough force must be used inserting the pin toovercome the force of the gapping spring. Lifting itas shown will facilitate this process.

4.) As shown in figure 3-2, squeeze to apply a force on the bluemolded sensor support. The extension spring (visible) shouldeasily compress, and that end of the sensor support should moveabout 1/8". While holding in the compressed position, tighten the1/4-20 locknut until snug, about 1/3 to 1/2 turn after the locknutcontacts the housing (about 35 in-lbs).

5.) The sensor assembly may now be reinstalled into the statorhousing and gapped per the GAPPING SEQUENCE in Section II(page 4).

ROTOR REMOVALIf the motor shaft is rusted or damaged, remove rust and burrsbefore removing the rotor.

END-OF-SHAFT style: Remove hardware holding the rotor to theshaft.

THROUGH-SHAFT style: Loosen the set screws holding the rotorto the shaft.

Remove the rotor by hand, taking care not to damage the outermagnetized ring.

Anti-seize is supplied and should be applied at installation to keepthe rotor from seizing to the shaft. If the rotor can not be removedby hand use a gear puller taking care not to damage the outermagnetized ring. DO NOT APPLY HEAT TO THE ROTOR.

RENEWAL AND SPARE PARTS

Tables 3-1, 3-2, and 3-4 provide rotor part numbers and installationhardware kit part numbers for the various shaft sizes and types. Alldimensions are in inches (except as noted).

BLACK

RED

GREEN

YELLOW

BLUE

GRAY

ORANGE

WHITE

BROWN

VIOLET

OUTPUT OPTIONS

A

B

D

G

E

H

C

I

F

J

94

5

10

2

837

61

+V(OUT)

Z

Z

A

B

B

A

+V

COM

Vcc

OUT

COM

300 OHMMIN.

GND

FUNCTION

PULSE GENERATOR

ØB

ØA

ØA

ØB

4-16 VDC SOLID STATE RELAY

Q5

MMFT6661

LINEDRIVERNOTE 1

CR8 {FUNCTIONAL DIAGRAM

50 mA MAXIMUM

N&K C&L P&Z T

ALM

MARKERMARKER COMPLEMENT

COMMON+V (Encoder Power)

{BLACK

RED

GREEN

YELLOW

BLUE

GRAY

ORANGE

WHITE

BROWN

VIOLET

N&K C&L P&Z T

OUTPUT OPTIONS

A

B

D

G

E

H

C

I

F

J

94

5

10

2

837

61

ALM

+V(OUT)

Z

Z

A

B

B

A

+V

COM

MARKERMARKER COMPLEMENT

GND

FUNCTION

+V (Encoder Power)

COMMON

24

VDC

RELAY

+

-

POWERSUPPLY

115 VAC

SINK 100 mA MAXIMUM,WITHSTAND 50 V MAXIMUMREFERENCED TO COMMON

Q5

MMFT6661

PULSE GENERATORFUNCTIONAL DIAGRAM

ØB

ØA

ØA

ØB

LINEDRIVERNOTE 1

CR8

NOTE 1: LINE DRIVER/VOLTAGE INPUT OPTIONS

1 3 5

LINE DRIVER 4428 4428 7272

Example 2. Alarm Output Using Separate 24 VDC Power Supply and Relay.

Applies to Model M285, M485, and M685 Encoders. For more information, refer to documentation received with the equipment, orcontact Avtron at 216-642-1230.

ALARM OUTPUT CONNECTION

Avtron SMARTach encoders provide an alarm signal if maintenance is required under specific circumstances. An optional internalalarm LED indicator is also available. Green indicates power on, red indicates alarm on. Following are application examplesprovided to help install the alarm output.

Example 1. Alarm output using +V(OUT). +V(OUT) is equal to +V, the encoder power supply.

SMARTach™Application Examples

FIGURE 2-5

8

9

PIN OUT

COM

+V

A

A–

B

B_

Z

Z_

+V (OUT)

ALM

BLACK

RED

GREEN

YELLOW

BLUE

GRAY

ORANGE

WHITE

BROWN

VIOLET

OPTION“N” & “K”

OPTION“C” & “L”

OPTION“P” & “Z”

OPTION“T”

OPTION“R”

A

B

D

G

E

H

C

I

F

J

1

6

2

7

3

8

4

9

5

10

COMMON

+V

ØA

ØA–

ØB

ØB_

MARKER

MARKER COMPLEMENT

RELAY +V REF*ALARM*

GROUND

* FOR OPTION “G” Pin 5 is not used and Pin 10 is cable shield.

*FOR OPTION “G” Pin 5 is not used and Pin 10 is cable shield.

FUNCTION

FOR DIFFERENTIAL APPLICATIONS

F

D

A

H

B

J

C

K

not used

not used

E shield

G case

1

6

2

7

3

8

4

9

NC*

NC*

OPTION“G”

+V (Encoder Power)

ØB

ØA

COMMON

MARKER

RELAY +V REF*ALARM*

GROUND

FUNCTION

FOR SINGLE ENDED APPLICATIONSPIN OUT

+V

B

A

COM

Z

+V (OUT)

ALM

RED

BLUE

GREEN

BLACK

ORANGE

BROWN

VIOLET

OPTION“N” & “K”

OPTION“C” & “L”

OPTION“P” & “Z”

OPTION“T”

OPTION“R”

B

E

D

A

C

F

J

6

3

2

1

4

5

10

D

B

A

F

C

not used

not used

E shield

G case

B

C

E

A

D

not used

not used

OPTION“E” & “F”

6

3

2

1

4

NC*

NC*

OPTION“G”

FOR SINGLE ENDED SINGLE PHASE WIRING APPLICATIONS

RED

GREEN

BLACK

A

B

C

D

E

COMMON

+V (Encoder Power)

SIGNAL

GROUND

CABLE BELDEN 8771OR EQUIVALENT

OPTION**“H” & “J” **(M727A Replacements)

WIRING DIAGRAMS

TYPICAL WIRE SELECTION CHART for 18 AWG, multiple pair, individually shielded

2 PAIR 9368 6062

ALPHABELDEN

3 PAIR 9369 6063

9389

9388

6 PAIR

4 PAIR

6066

6064

NOTES: See figure 2-5 page 8 for examples of alarm output wiring.

Marker output for connector options “H” & “J” - Pin “C”.

EU Declaration of Conformity: The Model M285 SMARTach™ Encoder has been assessed and type tested against the followingHarmonized European Standards: EN 50081-1:1992, EN 50082-1: 1998. The Model M285 has been found to be compliant with therequirements of EU Directive 89/336/EEC provided that the following conditions are met: The electrical supply to the M285 must be withinspecified limits. The electrical supply must offer suitable protection from voltage surges unless the application does not require suchprotection. On behalf of Avtron Manufacturing: Stephen L D’Henin, Certification Manager, Epsilon Certification Service.

FIGURE 2-6

8901 E. PLEASANT VALLEY RD., INDEPENDENCE, OH 44131, U.S.A. • (1) 216-642-1230 • FAX (1) 216-642-6037 • www.avtronencoders.com

REV: 05-25-07

SMARTach™ is a trademark of Avtron Mfg., Inc. Features and specifications subject to change without notice.Avtron standard warranty applies. All dimensions are in inches (mm).

10

1.574(40.00)0.217 (5.50)

4 HOLES2.047

(52.00)

4.25(108.00)

0.19 (4.83)

1.19(30.23)

(215.900)(215.976)

DIA

DRAIN PLUG 1/8 - 27 N.P.T.

NOTE: If the pulse generator will beexposed to water spray, the bottom1/8" pipe plug should be removed.

2.54(64.52)

8.5008.503 DIA

0.24(6.10)

45°

0.562 (14.275) DIA - 4 HOLESEQUALLY SPACED ON A7.250 (184.150) DIA.

8.75 (222.25)

4.62(117.35)

4.38(111.25)

9.00 (228.60) DIA

STANDARD:1/2-14 NPT

COVER PLATESINGLE OUTPUTONLY

OPTION “P”, “G”,“V”PLUG-IN INDUSTRIAL CONNECTOR

ALTERNATES SHOWN BELOW

OPTION “N”FLEXIBLE WATER-PROOF CONDUIT

5 FT (1524)

STATOR HOUSING

RIGHTMODULE

LEFTMODULE

OPTIONAL LED INDICATOR(AVAILABLE WITH ANYCONNECTOR OPTION)

CLEVELAND, OHIO

OPTION "K"CONDULET

3.84(97.54)

3.88(98.55)

STANDARD:1/2-14 NPT

36.75 (933.45)

3.228(82.00)

3.70(94.00)

1.21(30.73)

0.20(5.08)

OPTION "Z"PLUG-IN INDUSTRIAL CONNECTOR

OPTION "L"RIGHT ANGLE

"MS" CONNECTOR

3.85(97.79)

3.62(91.95)

REF

OPTION "C""MS" CONNECTOR

1.46(37.10)

OPTION "R"SMALL "MS" BULKHEAD

1.79(45.47)

OPT."R"

OPT."C"

OPTION "T"BOX IS 3.12" (79.25) DEEP

5.50(139.70)

4.75(120.65)

0.38(9.65)

3.00(76.20)

2.00(50.80)

1.12(28.45)

TERMINAL BLOCK

0.312 (7.925)DIA - 4 HOLES

5 FT (1524) OF FLEXIBLEWATERPROOF CONDUITBETWEEN PULSE GENERATORAND JUNCTION BOX

OUTLINE DIMENSIONS AND OPTION DETAILS

DIMENSIONSFigure 2-7 provides outline dimensions of the Avtron Model M285 SMARTach Encoder. The various output connection options availableare also illustrated. All dimensions are in inches. (millimeter)

Dimensions in parenthesis are in millimeters.All dimensions are approx.

FIGURE 2-7