genDesigners’ Manual

This Xgen Designers’ Manual has been prepared by Excelsys experts to assistsuitably qualified engineers and technicians in understanding the correctsystem design practices necessary to achieve maximum versatility andperformance from any of the Xgen series family of products.

1 Overview of Xgen series2 Part numbering system3 Installation considerations4 Xgen DOs and DON’Ts5 Theory of operation6 Xgen configuration7 powerMod operation8 powerMod signals9 powerPac operation10 powerPac (global) signals11 powerPac options12 Power ratings13 Reliability14 Safety15 EMC16 Connectors17 Mechanical specifications

Section 1 Overview of Xgen series

The Xgen series allows users to instantly configure high efficiency, off-line power sup-plies. Although very small in size, (40.4mm wide, 260mm long and either 89mm or127mm wide) the Xgen series provides up to 1,200W of output power. The chassis has4 or 6 slots and can provide up to 12 isolated outputs.

A complete power supply is configured by selecting and inserting up to six same lengthslide-in output assemblies called powerMods incorporating high efficiency switchingtechniques and leading edge technologies from Excelsys and available in a wide arrayof output voltages and power levels. The net result is a power supply that offers theadvantages of a custom supply, but is assembled from standard and modular buildingblocks continuing the Excelsys tradition of industry leading configurable power supplies.For detailed information about the powerMods, refer to the powerMod datasheet and/orthis designers’ manual.

Manufactured in world class power supply facilities under Excelsys control, the Xgenseries is completely user configurable. If output requirements change, i.e., more poweror a different output voltage is needed, upgrading is easy: simply unlock a single screwand replace the slide-in powerMod assembly with the preferred alternative. Allowingadditional flexibility, powerMods can be connected in parallel to increase output power,or in series for higher voltages (subject to staying within isolation ratings and giving dueconsideration to any SELV requirements.

A user-friendly interface on connector J3 of each powerMod provides control and out-put sequencing capability, in addition to useful status indicators. Please consult ourExcelsys applications team if you have other special requirements.

The Xgen series power supplies combine feature-laden front-ends (powerPacs) withslide-in output converters (powerMods). The plug-together architecture facilitates‘instant’ custom power solutions with industry leading 15W/in3 power density and up to90% conversion efficiency. Available in two pacakge sizes, with a varierty of applicationspecific powerPacs, the Xgen series provides a standard off-the-shelf solution for spe-cific application requirements.

The tables overleaf summarise various model families in the Xgen series together witha summary of the outline specifications for each model.

Contents

preliminarypage1

preliminary

Standard Features• Input Voltage: 85V to 264Vac 47 to 63 Hz• Outputs: 6 slots (up to 12 outputs)• Full power output to 50°C; half power to 70°C• Low inrush current• Integral Field Replaceable fan• Conducted EMI meets EN 55022 Level B• AC Fail status signal• Output Sequencing capability• Global shutdown capability• Overcurrent protection standard on all outputs.• Overvoltage protection on all powerMod outputs• Overtemperature limiting on all powerMods• Safety Agency Approvals: CE Mark, UL, CSA• DC OK (Power Good) status signal• Wide output voltage adjustment range

Optional Features• Thermal Signals suite (Over Temp and FanFail signals)• Reversed fan airflow direction

Section 2 Part numbering system

The part numbering system (explained below) clearly identi-fies which powerMods are factory installed into particularpowerPacs. This is also clearly indicated on the output labelsituated on top of the power supply.

Full specifications for each model are given in the relevantfamily datasheets, Refer to http://www.excelsys.com fordetails

MODEL Vmin Vnom Vmax Imax Imin Type Watts *

Xg1 1.5 2.5 3.6 50A 0A A 125W

Xg2 3.2 5.0 6.0 40A 0A A 200W

Xg3 6.0 12.0 15.0 20A 0A A 240W

Xg4 12.0 24.0 30.0 10A 0A A 240W

Xg5 28.0 48.0 58.0 6A 0A A 288W

Xg7 5.0 24.0 28.0 5A 0A AB 120W

Xg8 V1 5.0 24.0 28.0 3A 0A B** 72W

V2 5.0 24.0 28.0 3A 0A 72W

powerMods

Model

Slot A

Slot B

Slot C

Sum of option codes

‘-’,P

Slot F

Slot C

Slot D

Factory use only

}Xgen Option Codes01 Thermal Signals02 Reverse Fan

XCC 031 3 4 5 P A62

‘0’ if unused

powerPacs

Family MODEL Watts

Xcite XCA 400WXCB 700WXCC 1000WXCD 1200W

General Applications (4slot package, 89mm wide)

General Applications (6slot package, 127mm wide)

Medical Applications (4slot package, 89mm wide)

Family MODEL Watts

Xmite XMA 200WXMB 400WXMC 600W

Medical Applications (6slot package, 127mm wide)

Family MODEL Watts

Xvite XVA 400WXVB 700WXVC 1000WXVD 1200W

High Temperature (6slot package, 127mm wide)

Family MODEL Watts

Xhite XHA 400WXHB 600W

Low Acoustic Noise (4slot package, 89mm wide)

Family MODEL Watts

Xkite XKA 200WXKB 400W

Low Acoustic Noise (6slot package, 127mm wide)

Family MODEL Watts

Xqite XQA 400WXQB 900W

Medical Low Acoustic Noise (4slot package, 89mm wide)

Family MODEL Watts

Xrite XRA 200WXRB 400W

Medical Low Acoustic Noise (6slot package, 127mm wide)

Family MODEL Watts

Xzite XZA 400WXZB 900W

Family MODEL Watts

Xlite XLA 200WXLB 400WXLC 600W

page2

preliminarySection 3 Installation considerationsXgen series models may be mounted on any of three sur-faces using standard M4 screws. The chassis comes with fourmounting points on the base; maximum allowable torque is2Nm. The maximum penetration depth is 6mm. Additionally,the fleximountTM system on both side walls of the powerPacchassis facilitates flexible mounting.

When selecting a mounting location and orientation, the unitshould be positioned so air flow is not restricted. Maintain a50mm minimum clearance at both ends of the Xgen powersupply and route all cables so airflow is not obstructed. Thestandard unit draws air in on the input side and exhausts airout the load side. If airflow ducting is used, avoid sharp turnsthat could create back pressure. The fan moves approximate-ly 10Litres/sec (20 CFM) of air.

Avoid excessive bending of output power cables after they areconnected to the Xgen powerMods. For high-current outputs,use cable-ties to support heavy cables and minimize mechan-ical stress on output studs. Be careful not to short-out toneighboring output studs. Xgen powerMods are supplied withspring washers on all output screws. These (or equivalents)should be used and thread locking compounds are notrequired. The maximum torque recommended on output con-nectors is 4Nm. Avoid applications in which the unit isexposed to excessive shock or vibration levels that exceedthe specified levels. In such applications, a shock absorptionmounting design is required.

Section 4 Xgen DOs and DON’Ts

• Always fill all output slots of the Xgen. If a slot is not filledwith a powerMod, it should be filled with an Empty Slot Cover(part numbers XB1, XB2 or XB3). Empty Slot covers are plas-tic assemblies whose main function is maintain proper air-flow. Excessive airflow escape from an empty slot maydegrade thermal performance, and result in overheating anddamage to the Xgen unit.• Do not unplug or plug in powerMods while input power is

applied to the powerPac. The Xgen series is not designed forhot-plug applications.• Do not restrict airflow to the unit. The cooling fan draws airinto the unit and forces it out at the output terminals.• Always ensure that output screws are properly torquedbefore applying power to the powerPac.• Positive and Negative power cables should be run next toeach other to minimize inductance.• Wait 2 minutes after shutting off power before inserting orremoving powerMods.• Xgen assemblies do not have user serviceable components.They must be returned to the factory for repairs. ContactCustomer Service for a RMA number before returning theunit. Do not attempt to repair or modify the power supply inany manner other than the exchange of powerMods asdescribed in this Designers’ Manual.• Use proper size wires to avoid overheating and excessivevoltage drop.

Section 5 Theory of operation

The Xgen is comprised of an appropriate powerPac and aselection of powerMod DC output modules selected to deliverthe exact volts and amps requirements of the system design-er. See the operational block diagram below.

The Xgen powerPac modules consist of a fan-cooled semi-enclosed chassis containing circuitry for an off-line singlephase AC front end, EMI filter, cooling fan, system interfaceand associated housekeeping circuits. Input AC mains voltage(L1/N, L2 and GND) is applied to an IEC320 type input con-nector and then through an EMI filter designed to meetEN 55022 Level B. For medical applications, the EMI filteralso ensures that the power supply meets the low earth leak-age current requirements EN60601-01.

At start-up, inrush current is limited by an active soft-start cir-cuit integrated with the power rectifier circuitry. This stage isthen followed by a high frequency switching input currentshaping boost converter feeding the ZVS (Zero VoltageSwitching) resonant switching stage.

L

E

N

EMI Filter

EN55022 Class BMedical Low Leakage

Bulk Storage Capacitors

Current Shaping Transformer

Isolated Bias Supply 5V @ 250mA

ZVS Resonant Switching Stage

Medically Isolated Planar Transformer

Synchronous Rectified Output Converter

powerMod signals +Sense Inhibit - Sense Enable V trim I trim Power Good

Signals AC Fail Global Inhibit Global Enable Fan Fail Over Temp

Operational Block Diagram of Xgen Series

page3

preliminaryVoltage AdjustmentThe Xgen series has been designed with maximum user flexi-bility as a key objective. With regards to voltage adjustmentthis has been achieved by the wide range of adjustment oneach of the powerMod models. Voltage adjustment may beachieved by:

1. Front-panel potentiometer adjustment (all powerMods)2. Remote resistive programming (powerMods Xg1-Xg5)3. Remote voltage programming (powerMods Xg1-Xg5)

See diagrams below for details on external connections to theV trim pin (J3 pin3) required for remote voltage programming.

Remote Voltage Programming using a Voltage SourceUsing an external Voltage source (Vcontrol), the powerModoutput voltage may be adjusted over a wide range. ThepowerMod output voltage may be programmed by referring tothe Voltage Programming graph and applying formula belowto set the powerMod output voltage to the required level.

Voutput = K x Vcontrol (1)

The appropriate K factor for different powerMods are inVoltage Programming table.Important: Vcontrol must not exceed 2.5V.

The ZVS stage supplies power to a variety of powerModassemblies that provide the desired low voltage, regulatedoutputs. Conversion in the output assemblies is achieved bythe most advanced high efficiency converters resulting inreduced size for magnetics and capacitors; excellent line andload regulation; wide adjustment range for output; and lowEMI/RFI emission.

At initial power-up, the Xgen outputs are disabled to eliminateinrush current, a low-power flyback converter operating withPWM current-mode control converts the high voltage bus intoregulated low voltage to power the internal housekeeping cir-cuits and cooling fans. Once the bus potential is within oper-ating parameters, the AC Fail signal is activated indicatingthat the input power is OK, and allows the installed powerModoutputs to come up. An auxiliary bias supply of 5 Vdc rated at250mA is provided for peripheral use on interface connectorJ2. In the case of medically approved supplies, this bias sup-ply has medical isolation (4000VAC)

Outputs may be either globally enabled or inhibited via con-tact closure signals applied to J2.

Section 6 Configuration (and Reconfiguration)powerMods may be easily added, replaced, or moved by slid-ing the assemblies in or out of a powerPac chassis.

Prior to removing or installing a powerMod module, removepower from the powerPac and wait 2 minutes. Failure to doso can result in personal injury and/or damage to the supply.Take standard ESD precautions when handling powerMods.

Removing powerModspowerMods may be removed by removing the screw on thetop surface. Once this screw has been removed thepowerMod will slide out of the chassis. Once a powerMod hasbeen removed, the empty slot MUST be filled with eitheranother powerMod or an emply slot cover. If the slot is leftempty, it will provide an air-flow escape and may cause inad-vertent shutdown of the unit.

Installing powerModspowerMods may be installed in empty slots by simply slidingin the new powerMod, pushing the module ‘home’ until themounting bracket lines up with the hole in the Top Panel, thensecuring the module with the M3 x 6 countersunk screw pro-vided. Power and interface connections can be made afterthe powerMod has been installed.

powerMods may be paralleled for more power using bus bars(paralleling Links) across the positive and negative output ter-minals. See Section 7, powerMod operation:ParallelConnection of powerMod outputs

Section 7 powerMod operationThe Xgen series of products have been designed to allowmaximum flexibility in meeting the unique requirements ofindividual users. The inherent flexibility resulting from modu-larity concepts is further enhanced by this flexibility. Althoughthe products are very versatile, care should always be takento ensure that the proper procedures are followed.

Vcontrol

Vtrim (J3 pin 3)

-Sense (J3 pin2)

pow

erM

od

Remote Voltage Programming Using a Voltage Source

Remote Voltage Programming Using a Resistor

pow

erM

od

Rtrim

-Sense (J3 pin2)

Vtrim (J3 pin 3)

30% Vnom

Vnom

2.5V

Vmax

Voutput

Vcontrol

Slope = K

Voltage Programming Graph

Voltage Programming TablepowerMod K

Xg1 2.5Xg2 2.5Xg3 6.25Xg4 12.5Xg5 24.25

page4

preliminary

K for Xg4 = 12.5Vout = 20VUsing equation (3)

Rtrim= 8433 ohm

Alternatively if the powerMod voltage is set to via the onboard potentiomenter to another level e.g. 21V then the fol-lowing formula must be used to calculate the value of Rtrim

For powerMod Xg1 and Xg2

Rtrim = Vout[(3700 +10KVp(1-Vp)] -K(100Vp+67.5) (4)K(Vp +0.675) -Vout]

For powerMod Xg3, Xg4 and Xg5

Rtrim = Vout[(3700 +10KVp(1-Vp)] -K(100Vp+127.50) (5)[K(Vp +1.275) -Vout]

where Vp is the powerMod setpoint voltage expressed as aproportion of the total trim range.Vp =(Vmax-Vmin) (6)

(Vset-Vmin)

Example.To set powerMod Xg4 to 15V when powerMod Vset is 21V

Using equation (6) Vp = (30-12)(21-12)

Vp =0.5

K= 12.5Vout =15V

Example:Using a powerMod Xg4, what external voltage must beapplied to Vtrim pin in order to set powerMod output voltageto 20V.

Voutput = 20V, K=12.5Using equation (1); Voutput/K=Vcontrol20V/12.5 = 1.6V.

Vcontrol = 1.6V

Remote Voltage Programming using a Resistor.The powerMod output voltage can be adjusted downwardsusing a remote potentiometer,or reduced, using an externalresistance.

Calculation of the the external resistance depends on theactual initial voltage setting of the powerMod (via the on-board potentiometer). The preferred method is to set thepowerMod voltage to its maximum rating. e.g. Xg4 set to 30V.This will allow the widest possible adjustment range of theoutput voltage.

powerMod set to Vmax (Vmax=1)For modules Xg1 and Xg2

Rtrim= [3700Vout - 167.5] (2)[1.675K-Vout]

For module Xg3, Xg4 and Xg5

Rtrim= [3700Vout - 227.5K] (3)[2.275K-Vout]

Example.Using a powerMod Xg4, determine the resistance value to beapplied to Vtrim pin in order to set powerMod output voltage to20V.

*sc = Short Circit Current Limit

Vmin Vnom Vmax Imax I limitadjustminmax

CurrentLimit

OnsetSC*

I foldback V trimrangeminmax

I trim rangeminmax

OVP 1tracking

% of Vset

OVP 2Fixed

% of Vmax

RemoteSense

J3 signals

Xg1 1.5V 2.5V 3.6V 50A 0A

55.0A

55.0A

58.0A

Yes 0.75V

4.0V

0A

55.0A

110-115% 110-125% 0.5V+senseVtrimInhibit+PG

-senseItrim

Enable-PG

Xg2 3.2V 5.0V 6.0V 40A 0A

44.0A

44.0A

46.0A

Yes 1.5V

6.6V

0A

44.0A

110-115% 110-125% 0.5V+senseVtrimInhibit+PG

-senseItrim

Enable-PG

Xg3 6.0V 12.0V 15.0V 20A 0A

22.0A

22.0A

23.0A

Yes 3.6V

16.5V

0A

22.0A

110-115% 110-125% 0.5V+senseVtrimInhibit+PG

-senseItrim

Enable-PG

Xg4 12.0V 24.0V 30.0V 10A 0A

11.0A

11.0A

12.0A

Yes 7.2V

33.0V

0A

11.0A

110-115% 110-125% 0.5V+senseVtrimInhibit+PG

-senseItrim

Enable-PG

Xg5 28.0V 48.0V 58.0V 6A 0A

6.6A

6.6A

7.0A

Yes 14.4V

59.0V

0A

6.6A

110-115% 110-125% 0.5V+senseVtrimInhibit+PG

-senseItrim

Enable-PG

Xg7 5.0 24.0 28.0 5ANo

5.5A

6.0A

No No No No 110-125% No+PG-PG

InhibitCommon

Xg8V1

5.0 24.0 28.0 3ANo

3.3A

4.0A

No No No No 110-125% No

V1 V2

Xg8V2

5.0 24.0 28.0 3ANo

3.3A

4.0A

No No No No 110-125% No+PG-PG

InhibitCommon

+PG-PG

InhibitCommon

page5

preliminaryUsing equation (5)

Rtrim = Vout[(3700 +10KVp(1-Vp)] -K(100Vp+127.5)[K(Vp +1.275) -Vout]

Rtrim = 7478 ohm

The power rating of the trim resistor can be as low at 100mW

Over Current Protection (OCP)A variety of over current protection methods are possible withthe Xgen series. See the powerMod table which indicates theavailable current limit modes on each unit.

powerMods Xg1 to Xg5 can have Straight-line current limit orFoldback current limit. See powerMod table for nominal cur-rent limit values.

Simple external application circuits may be used to achieveprogrammable foldback current and user programmable cur-rent limit levels (reduced). See Current Limit Programmingdiagrams and Current Limit Characteristics diagram.

The default current limit characteristic is Straight Line CurrentLimit.

Programming Current LimitThe current limit can be programmed to your requirements (inboth Straight line and Foldback modes).

Straight line Current Limit can be programmed using an exter-nal voltage source or resistor/potentiometer. Connectionbetween the Itrim pin (J3 pin4 and the -Vout terminal will setthe current limit to the desired level.

Straight Line Current Limit Using a Voltage Source.

The formula below will calculate the required external controlvoltage.required to set the current lmit of a powerMod:

Vcontrol = FIlim - VD + 1 (7)

Where F is a conversion factor for each powerMod.

VD is the voltage drop across BAW56W. This can beassumed to be 0.5V for calculations, however it will varyslightly due to temperature. Refer to BAW56W datasheet forfurther details.

Example:To set the current limit of Xg1 to 20A, determine the externalvoltage to be applied to the Itrim pin.

Ilim = 20AF = 0.0308 for Xg1VD = 0.5VUsing equiation (7)

Vcontrol =1.116V

Note that application of any voltage >2.5V to Itrim will notincrease current limit beyond the powerMods normal currentlimit.

Straight Line Current Limit Using an External Resistor.The formula below will calculate the required external resistorvalue required to set the current limit of a powerMod:

R I limit = 1320[(3-VD) -1] (8)(2-FIlim)

Example:To set the current limit of Xg2 to 30A, what resistance mustbe placed between the Itrim pin and -V.Ilim = 30AF= 0.0308 for Xg1VD = 0.5VUsing equiation (8)

R I limit = 1747 ohm

Foldback Current limit ProgrammingFoldback Current LImit can be achieved using the circuitoverleaf. The onset of Foldback current limit (I fb1) can be pro-grammed using the formula below as can the actual end point (I fb2).

To set the final Foldback current limit point (I fb2), the value R1in parallel with R2 is equivelant to R I limit in the previousStraight Line current limit example.

R I limit

Itrim (J3 pin 4)

-V (J4 pin1)

Straight Line Programmable Current Limit

powerMod

Vi=3V

1320 ohm

Vlim

BAW56W Vcontrol

VD

Current Limit TablepowerMod F

Xg1 0.0308Xg2 0.0308Xg3 0.09108Xg4 0.14935Xg5 0.2987

I Foldback

Straight Line Current Lim

it

V set

V max

Hiccup Limiting

I max

Foldback Current L

imitin

g

Current Limit Characteristics

I fb1

I fb2 I fb1

page6

preliminary

To set I fb1, point, we must calculate the ratio of R1 to R2.

To get the value of R1:

R1 = (R I limit)Vout (9)[FIfb1(1 + R I limit) - 2R I limit +1 -VD]

1320 1320

R2 = (R1)(RI limit) (10)R1 - R I limit

ExampleTo set the foldback current limit of an Xg2 set at 5V to the fol-lowing levels, I fb1 =30A and I fb2=20A, determine the valuesof R1 to R2. required.

Vout 5VF = 0.308I fb1 =30AI fb2=20AVD=0.5V

To set I fb2 to 20A, we need the to set R I limit equivelant paral-lel resistance of R1 in parallel with R2.

Using equation (8)R I limit = 1320 [(3-VD) -1]

(2-FI fb2)

R I limit = 1064 ohm.

To calcluate the ratio of R1 to R2 use the formula above

Use equation (9)n to get the value of R1

R1 = 9556 ohm

Use equation (10) to get the value of R2

R2 =1197 ohm

Over Voltage Protection (OVP)Over-voltage protection is implemented on each XgenpowerMod output as a two-level scheme, where the1st levelof protection tracks the set voltage Vset and the 2nd level ofprotection is set at a fixed level.

1st Level: 110-115% of Vset (where Vset is less than Vmax ofpowermod. This is only available on powerMods Xg1-Xg5.

2nd level: OVP level is fixed relative to Vmax 110-125%(Latching).

2nd Level Overvoltage protection is Latching and it may bereset by removing and reinstating AC power from the XgenpowerPac input.

Power Limit.Each powerMod has a number of levels of protection in orderto ensure that Xgen is not damaged if used in overload condi-tions. See graph below

When Vset is less than or equal to Vnom, current limit isemployed at the current limit set point.However if Vset is greater than Vnom, power limit isemployed to ensure that the powerMods does not exceed itspower rating. e.g. Xg4 is adjustable between 12V and 30V. Imax is 10A.Power rating is 240W.At 24V the powerMod can deliver 10A continuously, i.e 240W.However at 30V, the powerMod can still deliver 240W, howev-er this equates to 8A continuous.

Remote SenseTo compensate for voltage drops in the output leads, useremote sensing. Remote sensing is available on all single out-put modules and on the first output (V1) on dual modules.

Remote sensing may be implemented by connecting thePositive Sense pin (J3 pin1) to the positive side of the remoteload and the Negative Sense pin (J3 pin2) to the negativeside of the remote load. The maximum line drop, which canbe compensated for by remote sensing, is 0.5V, subject to notexceeding the maximum module voltage at the output termi-nals.

+V(J4 pin 2)

-S (J3 pin2)

Remote Sensing

powerMod

+S (J3 pin1)

-V (J4 pin1)

+

+

LOA

D

R1

R2

C

C

R2

Itrim (J3 pin 4)

-V (J4 pin1)

Foldback Programmable Current Limit

powerMod

Vi=3V

1320 ohm

Vlim

BAW56W

VD

V (J4 pin2)

R1

Vnom

Vmin

Vmax

I max

Power Limit Zone

Continuous Operation Zone

page7

preliminarySeries Connection of powerMod outputsIt is possible to connect powerMods in series to increase out-put voltage.

Outputs are rated SELV (Safety Extra Low Voltage), that is,output voltages are guaranteed to less than 60 volts. StackingpowerMods can exceed SELV, the user must take appropriateprecautions. It is good practice to stack powerMods with simi-lar output current limits, so that in the case of short circuit theoutputs collapse together,

If remote sensing is required, the exterior sense connectionsshould connect to the load at point of use, and the interiorconnections to the local sense. Special links for series con-nection of powerMods (part number XS1) to reduce wiringcomplexity can be specified and fitted by the installer oradded at the factory.

Parallel Connection of powerMod outputspowerMods may be paralleled to increase output current.Only powerMods of the same type may be paralleled and theinstaller should adjust the setting on each powerMod sepa-rately to the same value. i.e within 0.1% of the set voltage.

Excelsys supplies special parallel link connection bars (partnumber XP1) for parallel connection to reduce wiring com-plexity. These can be specified and fitted by the installer oradded at the factory

Observe the following precautions when remote sensing:1. Use separate twisted pairs for power and sense wiring.2. Route the sensing leads to prevent pick up, which mayappear as ripple on the output.3. Never disconnect the output power rail with the sensing stillconnected to the load.

In certain applications where there is a high dynamic imped-ance along the power leads to the sensing point; remotesensing may cause system instability. This system problemcan be overcome by using resistors in the sense leads(Positive sense lead: R1 = 100ohm , Negative sense lead:R2=10ohm ), together with local AC sensing, by using 22uFcapacitors between the remote sense pins and the output ter-minals.The resisitance of the power cables must be so that the volt-age drip across the cables is less tha 0.5V (to ensure remotesensing operates correctly.Rcable < 0.5

Ioute.g for an Xg2, 5V/40A. The Rcable must be less than12.5mohms

Measurement of Ripple & NoiseAs with all switched mode power supplies, it is important toensure that the correct method is used to verify ripple &noise. Care should be taken to ensure that a loop antenna isnot formed by the tip and ground lead of the oscilloscopeprobe as this would lead to erroneous readings consistingmainly of pickup from remnant radiation in the vicinity of theoutput connectors. Excelsys recommends the use of a x1probe with the ground sheath of the probe tip used for groundconnection.

In some applications, further erroneous readings may resultfrom CM currents. These can be reduced by looping a fewturns of the scope lead through a suitable high permeabilityferrite ring.

As most loads powered by a power supply will have at leastsmall values of differential capacitors located near the load,Excelsys also recommends the use of small value of capaci-tance (approx 1uF) positioned at the point of measurement.

Minimising System NoiseThere are a number of causes of poor system noise perform-ance. Some of the more common cause are lited below.

a. Insufficient de-coupling on the PCB or loadb. Faulty wiring connection or poor cable terminationsc. Poor system earthing

There are some simple steps to eliminate, reduce or identifythe causes of high frequency noise

a. Is the noise conducted or radiated? If changing the positionof the power supply or screening improves performance, thenoise is likely to be radiated. See Section 15. EMC: Guidlinesfor Optimum EMC Performance b. Twist all pairs of power and sense cables separatelyc. Ground connections (zero Volt) should be made with theshortest possible wiring via a capacitor to the nearest point onthe chassis.

J3

2 1

J3

Voltage Adjust

2 1

J3

2 1

J3

Voltage Adjust

2 1

page8

preliminaryThere are two methods of parallel connection.

Level 1 Paralleling. Current Share (powerMod DIP switch Ishare OFF). does notforce current sharing.

Level 2 Paralleling: (Recommended)This ensures current sharing between paralleled modulesand is the recommended mode for paralleling powerMods.Current Sharing is porportional to the dV (differencebetween the voltage settings of the powerMods.When connecting powerMods in parallel, please observethe following steps.

1. Attach the negative Parallel Link. 2. For Level 2 Paralleling, ensure that the powerMod DIPswitch on each powerMod is switched to Ishare ON 3. Set the voltage of powerMod 1 to the correct outputrequired.4. Measure the voltage difference (dV) between the positiveterminals of the powerMods and adjust powerMod 2 to min-imise dV.5. Attach the postive parallel link

The percentage of current sharing is calculated as follows/

IShare error% = 10000dV(11)

1.5Vmax

Remote Sense can be implemented as with a singlepowerMod. Simply connect the sense pins of the paralleledpoweMods. Bring the sense connections from one of the

powermod to the load.For Remote Voltage Adjustment of powerMods, please con-tact factory.

powerMod Start-Up and ShutdownpowerMod are designed such that all when input power isapplied, all outputs rise to their set point voltage simulate-noeusly.Like wise, when input power is removed all outputs com-mence to drop simulatenosly and reach Zero potentialsimultaneously.

Outputs can be sequenced using the enable function inorder to allow contolled start up if required.

Section 8 powerMod Signals

powerMod Enable/InhibitEach powerMod may be enabled/inhibited by means of anappropriate signal applied to an opto-isolated input on pinsJ3 pin 5 and J3 pin 6, on powerMods Xg1 to Xg5. Inhibit isavailable on J3 pin 7 on Xg7 and J3 pin3 and J3 pin 7 onXg8.The output voltage of the powerMod will be fully inhibited to0V.Maximum signal input voltage 12V.Minimum signal input voltage 3V.Minimum current required is 2mA.

The default mode is ‘Inhibiting’. This may be changed to‘Enabling’ by setting of the DIP switch on the powerMod.

powerMod Power Good SignalEach powerMod contains an internal comparator whichmonitors the output voltage and determines whether thisvoltage is within normal operation limits. Maximum collector current is 2mAMaximum Collector voltage is 30V

t7 < 30mst8 < 30ms

t7 t8

powerMod Enable

Vout

Power Good

pow

erM

od 2

Remote Sense with Paralleled powerMods

pow

erM

od 1

+V(J4 pin 2)

-S (J3 pin2)

+S (J3 pin1)

-V (J4 pin1)

+V(J4 pin 2)

-V (J4 pin1)

+S (J3 pin1)

-S (J3 pin2)

Load

page9

preliminaryWhen the output voltage is within normal limits, the PowerGood signal is activated.

An opto-isolated signal is generated and available on J3 pin7 and J3 pin 8. (opto-transistor ON = Good) for powerModsXg1 to Xg5. Available on J3 pin 5 and J3 pin6 for Xg7, onJ3 Pin1 pin2, pin 5 and pin 6for Xg8.

powerMod LED IndicatorThe LED indicator on each powerMod module gives a visu-al indication of the information contained in the Power Goodsignal above.

Section 9 powerPac operation

The Xgen powerPac provides the front end input power tothe Xgen powerMods. This is available in two package sizesand a number of power ratings. See Secton 11, PowerRatings for more detail.

Bias VoltageA SELV isolated bias (always on) voltage of 5V @ 250mA isprovided on J2 pin 2 relative to J2 pin 1 (common)and maybe used for miscellaneous control functions. For medical aplications, this bias supply voltage has4000VAC isolation

Section 10 powerPac (global) signals

AC FailAC Mains Fail signal is implemented by an Opto-isolatedsignal with a maximum sink current of 4mA. During normaloperation the transistor is ON. When the input voltage islost or goes below 80Vac, the opto-transistor is turned OFFat least 5mS before loss of output regulation (at nominal

powerMod voltage or below).80ms < t1 < 100ms80ms < t2 < 150mst3 = 10mst4 > 10mst5 > 5ms

Global InhibitA global inhibit function may be implemented via simplecontact closure as shown This function inhibits ALLpowerMod outputs except the auxiliary bias voltage. Globalinhibit also shuts down the powerPac fans.

Global EnableA global enable function may be implemented via simplecontact closure as shown in the diagram . Ensure that J2

pin 8 and J2 pin 1 are connected prior to contact closure.This function enables ALL powerMod outputs and thepowerPac fans.

Global Inhibit Using an External SignalA global inhibit function may be implemented using a signalfrom the system using the diagram shown.This functioninhibits ALL powerMod outputs. Global inhibit also shutsdown the powerPac fans.

Global Enable Using an External SignalA global enable function may be implemented using a signalfrom the system using the diagram shown overleaf.Thisfunction enables ALL powerMod outputs.

+5V @ 250mAJ2 pin 2

J2 pin 6

J2 pin 8

J2 pin 1

Bias Voltage

Global Enable

powerPac

Global Inhibit

Com

Global Inhibit using System Signal

Digital Source

+5V @ 250mAJ2 pin 2

J2 pin 6

J2 pin 8

J2 pin 1

Bias Voltage

Global Enable

powerPac

Global Inhibit

Com

Global Enable using Bias Supply

+5V @ 250mAJ2 pin 2

J2 pin 6

J2 pin 8

J2 pin 1

Bias Voltage

Global Enable

powerPac

Global Inhibit

Com

Global Inhibit using Bias Supply

t1

t2

t3

t4

t5

AC Fail

Vout

page10

preliminary

Section 11 powerPac options

Temperature Alarm (Option 01)Open collector signal indicating that excessive temperaturehas been reached due to fan failure or operation beyond rat-ings. This signal is activated at least 10ms prior to systemshutdown

Fan Fail (Option 01)Open collector signal indictaing that at least one of thepowerPac fans have failed. This does not cause power sup-

ply shutdown. The power supply will continue to operate untilthe 10ms after the Temperature Alarm signal iis generated.t8 > 10ms

Reverse Fan (Option 02)The Xgen series is available with reverse air flow direction.This is ideal to expel air from the system and works particu-larly well with the internal fan cooling built into the overall sys-tem. Reverse Air option is only available on XCA, XCB, XCC,XVA, XVB and XVC powerPacs.

Section 12 Power Ratings

When specifying an Xgen series power supply in an appli-cation it is necessary to ensure that powerPacs andpowerMods are operating within their power output capabili-ties.

powerMods are designed to provide maximum output powerat the nominal output voltages. The maximum permissibleoutput power that may be drawn from any powerMod isgiven in the powerMod specification table.

The power rating requirement of the powerPac must alwaysbe calculated by summing the powerMod powers specified

in the application. This sum must not exceed the powerPacpower rating.

Derating at Elevated TemperaturespowerMods and powerPacs (except the Xhite model family)must be derated for temperature, linearly from 100% of rated power at 50oC to 50% of rated power at 70oC.

Derating at Low Input VoltagesPlease refer to the specifc derating curves for the differentXgen families.Xcite and Xvite 1200watt models must be derated linearly forinput operating voltages below 120Vac from 1200watts at120Vac to 850watts at 85Vac.Xcite and Xvite 1000watt models must be derated linearly forinput operating voltages below 120Vac from 1000watts at120Vac to 850watts at 85Vac.

Xlite and Xmite 600watt models must be derated linearly forinput operating voltages below 180Vac from 600watts at180Vac to 400watts at 85Vac.Xkite and Xrite 400watt models must be derated linearly forinput operating voltages below 120Vac from 400watts at120Vac to 300watts at 85Vac.

600

26418012085

Derating Curve of Output Power Input Line Voltage

Input Voltage VAC

Out

put P

ower

W

500

400

200 XLA / XMAXLA / XMAXKA / XRAXKA / XRA

300

XLB / XMBXLB / XMB

XLC / XMCXLC / XMC

XKB / XRBXKB / XRB

100%

50%

-20˚ 70˚60˚50˚40˚30˚20˚10˚0˚-10˚

Derating Curve of Output Power versus Ambient Temperature

Ambient Temperature ˚C

Out

put P

ower

%

1200

26418012085

Derating Curve of Output Power Input Line Voltage

Input Voltage VAC

Outp

ut Po

wer W

1000

800

400 XCA / XVAXCA / XVA

600

XCC / XVCXCC / XVC

XCD / XVDXCD / XVD

XCB / XVBXCB / XVB700

+5V @ 250mAJ2 pin 2

J2 pin 6

J2 pin 8

J2 pin 1

Bias Voltage

Global Enable

powerPac

Global Inhibit

Com

Global Enable using System Signal

Digital Source

t8

Fan Fail

Vout

Temp Alarm

Temp

page11

preliminaryXqite and Xzite 900watt models must be derated linearly forinput operating voltages below 120Vac from 900watts at120Vac to 600watts at 85Vac.

The derating above refers to ‘average power’. Power peaksmust be limited to 5 seconds.

Section 13 Reliability

The 'bath-tub' curve shows how the failure rate of a powersupply develops over time. It is made up of three separatestages.Immediately after production, a relatively high number of

units fail due to defective components or production errors.To ensure that these early failures do not happen while inthe possession of the user, Excelsys carries out a burn-inon each unit, designed to ensure that all these early failuresare detected at Excelsys.

After this period, the power supplies fail very rarely, and thefailure rate during this period is fairly constant. The recipro-cal of this failure rate is the MTBF (Mean Time BetweenFailures).

At some time, as the unit approaches its end of life, the firstsigns of wear appear and failures become more frequent.Generally 'lifetime' is defined as that time where the failurerate increases to five times the statistical rate from the flatportion of the curve.

In summary, the MTBF is a measurement of how manydevices fail in a period of time (i.e. a measure of reliability),before signs of wear set in. On the other hand, the lifetimeis the time after which the units fail due to wear appearing.

The MTBF may be calculated mathematically as follows:

MTBF = total t / failure , where total is the total num-ber of power supplies operated simultaneously, failure is

the number of failures, and t is the observation period.

MTBF may be established in two ways, by actual statisticson the hours of operation of a large population of units, orby calculation from a known standard such as MIL-HDBK-217 and its revisions.

Determining MTBF by CalculationMTBF, when calculated in accordance with MIL-HDBK-217,involves the summation of the failure rates of each individ-ual component at its operating temperature. The failure rateof each component is determined by multiplying a base fail-ure rate for that component by its operating stress level.The result is FPMH, the failure rate per million operatinghours for that component.

Then FPMH for an assembly is simply the sum of the indi-vidual component FPMH.

Total FPMH = FPMH1 + FPMH2 + ………….. +FPMHnMTBF (hours) = 1,000,000

FPMH

In this manner, MTBF can be calculated at any temperature.The Xgen series has been designed to achieve the follow-ing failure rates at 25°C and full load.

powerMod 1.0 failures per million hourspowerPac 0.5 failures per million hours

Calculations based on MIL-HDBK-217 have confirmedthese targets.

The figures for the powerPac excludes fans.

Example:What is the MTBF of XLB4400-00XLB FPMH = 0.5Xg4 FPMH = 1.0Total FPMH = 2.0

MTBF = 500,000 hours

Determining MTBF experimentallyMTBF may also be determined from field data. Excelsysverifies its calculated figures by means of extended obser-vation over a large sample of units operating under specificconditions. Xgen units are currently (as of June 1st, 2004)undergoing experimental reliability testing as set out below.The results of this testing will be included in future issues ofthis document.

Number of Sample Units 50Power Supply Part Number XCD123458-00Ambient Temperature 40°C (35 to 45)

Input Voltage: 120VACInput Frequency: 50HzOutput Loading 1000W

Start date of Test June 1st, 2004Check date June 1st, 2005

900

26418012085

Derating Curve of Output Power Input Line Voltage

Input Voltage VAC

Out

put P

ower

W

600

XHA / XQAXHA / XQAXZAXZA

400

XQB / XZBXQB / XZB

XHBXHB

Time

‘Bath-tub’ Curve of Failure Rate over Time

page12

preliminaryTotal Hours of MTBF Test 438,000 unit hoursTotal Number of Failures 3.

MTBF = 146,000 hours

MTBF and TemperatureReliability and MTBF are highly dependent on operatingtemperature. The figures above are given at 40 degrees C.For each 10 degrees decrease, the MTBF increases by afactor of approximately 2.5. Conversely, however, for each10 degrees increase, the MTBF reduces by a similar factor.Therefore, when comparing manufacturer's quoted MTBFfigures, look at the temperature information provided.

Section 14 Safety Approvals

Low Voltage Directive (LVD) 73/23/EECThe LVD applies to equipment with an AC input voltage ofbetween 50V and 1000V or a DC input voltage between75V and 1500V. The Xgen series is CE marked to showcompliance with the LVD.

The relevant European Standard for Xcite and Xlite models isEN60950 (Information Technology).

The relevant European Standard for Xvite and Xmite medicalmodels is EN60601-1 (Medical Devices Directive).

With appropriate packaging, the Xgen can also meet therequirements of EN61010-1 for industrial scientific measur-ing equipment and process control.

The Xcite, Xlite, Xhite, Xqite and Xkite models are designed tocomply with the requirements of IEC950, EN60950,UL1950, CSA 22.2 No. 234 and IEC 1010, when correctlyinstalled in a limited access environment.

The Xvite, Xmite, Xzite and Xrite models are designed to com-ply with the requirements of IEC601-1, EN60601-1,UL2601-1 and CSA601-1, for non-patient connect applica-tions.

powerMods Xg2, Xg3, Xg4 and Xg5 are capable of provid-ing hazardous energy levels (>240 VA). Equipment manu-facturers must provide adequate protection to service per-sonnel.

Environmental ParametersThe Xgen series is designed for the following parameters:

Material Group IIIb, Pollution Degree 2Installation Category 2Class IIndoor use (installed, accessible to Service Engineers only).Altitude: -155 metres to +3050 metres from sea level.Humidity: 5 to 95% non-condensing.Operating temperature -20°C to 50°CDerate at 2.5%/°C from 50°C to 70°C.

Approval LimitationsUse in North AmericaWhen this product is used on 180 to 253 Volts AC mainswith no neutral, connect the two live wires to L (live) and N(neutral) terminals on the input connector.

StandardCreepage Distances Xcite, Xlite models

Primary mains circuits to earth: 2.5mm spacing Primary mains circuits to secondary: 5mm spacing

Dielectric strength Xcite, Xlite modelsPrimary mains circuits to chassis: 1500VACPrimary mains circuits to secondary: 3000VAC

MedicalCreepage Distances Xvite, Xmite models

Primary mains circuits to earth: 4mm spacing Primary mains circuits to secondary: 8mm spacing

Dielectric strength Xvite, Xmite modelsPrimary mains circuits to chassis: 1500VACPrimary mains circuits to secondary: 4000VAC

The primary to secondary test is not possible with modulesfitted to the unit, as damage to the EMI capacitors willoccur.

Output IsolationOutputs are each isolated 500V DC to each other and 500V DC to chassis.

Section 15 EMCEMC Directive 89/336/EECComponent Power Supplies such as the Xgen series arenot covered by the EMC directive. It is not possible for anypower supply manufacturer to guarantee conformity of thefinal product to the EMC directive, since performance is crit-ically dependent on the final system configuration.

System compliance with the EMC directive is facilitated byXgen compliance with several of the requirements as out-lined in the following paragraphs. Although the Xgen prod-uct series meet these requirements, the CE mark does notcover this area.

EMISSIONSPower Factor (Harmonic) CorrectionThe Xgen series incorporates active power factor correctionand therefore meets the requirements of EN61000-3-2, asdemonstrated by the test results set out below.

EN61000-3-2 Xgen Harmonic Currents (typical)Results taken at 640W Output Power

115V AC In 230V AC InHarmonic 1 6.420A 100% 3.030A 100%Harmonic 3 0.10A 1.6% 0.128A 4.2%Harmonic 5 0.11A 1.7% 0.106A 3.5%Harmonic 7 0.042A 0.7% 0.014A 0.5%Harmonic 9 0.067A 1.0% 0.062A 2.0%Harmonic 11 0.052A 0.8% 0.078A 3.5%Harmonic 13 0.044A 0.7% 0.064A 2.1%Efficiency 87% 91%

page13

preliminaryEN61000-3-3 Flicker & Voltage Fluctuation LimitsXgen power supplies meet the requirements of the limits onvoltage fluctuations and flicker in low voltage supply sys-tems.

EN55022 Class B Conducted EmissionsXgen SeriesUnder appropriate test conditions, the Xgen series meetsthe requirements of EN55022 Class B, without the need forexternal filtering.

IMMUNITYThe Xgen series has been designed to meet, and tested to,the immunity specifications outlined below:

EN61000-4-2 Electrostatic Discharge ImmunityLevel 48kV Air discharge applied to Enclosure6kV Contact with Enclosure

EN61000-4-3 Radiated Electromagnetic FieldImmunityLevel 310Volts/metre 26 to 1000Mhz applied to Enclosure

EN61000-4-4 Fast Transients-Burst Immunity(Common Mode)Level 44kV, 2.5kHz Repetition, Burst period 300ms

EN61000-4-5 Input Surge ImmunityLevel 3+/-2kV Common Mode 1.2/50 S (Voltage); 8/20uS (Current)+/- 1kV Differential Mode 1.2/50 S (Voltage) 8/20 S(Current)

EN61000-4-6 Conducted RFI10 V/m

EN61000-4-11 Voltage Dips95% drop 10msMeasured according to EN55024

Guidelines for Optimum EMC PerformanceThe Xgen series is designed to comply with EuropeanNormative limite (EN) for conducted and radiated when cor-rectly installed in a system. See performance levels attainedabove. However, power supply compliance with these limitsis not a guarantee of system compliance. System EMCperformance can be impacted by a number and combina-tion items. Design consideration such as PCB layout andtracking, cabling arrangements and orientation of the powersupply amongst others all directly contribute ot the EMCperformance of a system.

Cabling arrangements and PCB tracking layouts are thegreatest contributing factor to system EMC performance. Itbis important that PCB tracks and power cables are arrangedto minimise current carrying loops that can radiate, and tominimise loops that could have noise currents induced intothem. All cables and PCB tracks should be treated as radia-tion sources and antennae and every effort sghould bemade to minimise their interaction

a. Keep all cable lengths as short as possible.

b. Minimise the area of power carrying loops to minimise radiation, by using twisted pairs of power cables with the maximum twist possible..

c. Run PCB power tracks back to back.d. Minimise noise current induced in signal carrying

lines, by twisted pairs for sense cables with the maximum twist possible.

e. Do not combine power and sense cables in the same harness

e. Ensure good system grounding. System Earth should be a “starpoint”. Input earth of the equipment should be directed to the “starpoint” as soon as possible. The power supply earth should be connected directly to the “starpoint”. All other earths should go to the ‘starpoint”

Section 16 ConnectorsBelow are pinout connections and diagrams of the Xgenpower and signal connectors.

Output Connector PinoutPin J4 (type A) J4 (type B)1 -Vout -V22 +Vout +V23 -V14 +V1

J4 Mating Connectors:Type A: M4 Screw TerminalsType B: Phoenix p/n MSTB2.5/4-ST-5.08

Output Signals Connector PinoutPin J3(Xg1-Xg5) J3 (Xg7) J3(Xg8)1 + Sense not used -pg (V2)2 - Sense not used +pg (V2)3 V trim not used inhibit (V2)4 I trim common common (V2)5 +inhibit/enable -pg -pg (V1)6 -inhibit/enable +pg +pg (V1)7 +power good inhibit inhibit (V1)8 -power good common common (V1)

J3 powerMod Signals Mating Connector:Housing: Molex p/n 51110 or equivalentCrimp Terminal: Molex p/n 50394

J3

J4

Voltage Adjust

M4 Screws

2 1

2

1

8 7

J3

J4

V1 Adjust

2 1

1

3

4

2

V2 Adjust

8 7

Type A Xg1-Xg7 Type B Xg8

page14

preliminary

Input Connector and Signals Pinout J2 powerPacPin J1 J2 (powerPac)1 Line common2 Neutral +5V bias3 Earth4 ac fail5 fan fail*6 global enable7 temp alarm*8 global inhibit

* Option 01.

J1 Mating Connector:IEC320 type female plug rated 13A

J2 Signals Mating Connector:Housing: Molex p/n 51110 or equivalentCrimp Terminal: Molex p/n 50394

J1 J2INPUT AC 100V-240V 50/60HzSEE INSTRUCTION MANUAL70C MAX OPERATING TEMPERATURE

2

1

8

7

page15

preliminarySection 17 Mechanical Specifications

J1J2

INPU

T AC 100V-240V 50/60H

zSEE IN

STRU

CTIO

N M

ANU

AL70C

MAX O

PERATIN

G TEM

PERATU

RE

29.5040.40

122.0046.00

23.50

23.50

42.00

92.00

19.00 89.00

SLOT D

SLOT C

SLOT B

SLOT A

Third angle projection

TOP VIEW

All Dimensions in mm4-OFF M4 Mounting Holes on the BaseMax screw penetration is 6mm from Base

Xlite, Xmite, Xkite, Xrite,

J1J2

INPU

T AC 100V-240V 50/60H

zSEE IN

STRU

CTIO

N M

ANU

AL70C

MAX O

PERATIN

G TEM

PERATU

RE

29.5040.40

122.0046.00

23.50

23.50

80.00

92.00

19.00

19.00 127.00

SLOT F

SLOT E

SLOT D

SLOT C

SLOT B

SLOT A

19.00

Third angle projection

TOP VIEW

All dimensions in mm4 M4 Mounting holes on the BaseMax screw penetration is 6mm from Base

Xcite, Xvite, Xqite, Xhite, Xzite

page16

preliminaryContact Details.

Excelsys Technologies has an international network of rep-resentatives and distributors . All contact details can befound at http://www.excelsys.com

You can also contact us directly at the following:

Europe:Excelsys Technologies LimitedTel: +353 1 8900933Fax: +353 1 8901358email: sales@excelsys.com

Swords Business ParkSwordsCo. DublinIreland

North AmericaExcelsys TechnologiesTel: +1 972 771 4544Fax: +1 972 421 1805email: salesusa@excelsys.com

519 Interstate 30, #309,RockwallTX 75087USA

While every effort has been made to ensure the accura-cy of the contents of this handbook, ExcelsysTechnologies Ltd. cannot accept any liability for errorscontained herein.Excelsys operates a policy of Continuous ProductImprovement, and specifications are subject to changewithout prior notice.

Rev 02 : Jan 10th 2005

page17