ESAB Plasmarc EPP-450 - IGBT and Freewheeling Diode Replacement

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SECTION 6 TROUBLESHOOTING
6.4.2 IGBT / Freewheeling Diode (FWD) Replacement
The emitter and the gate of each aected IGBT must be jum-
pered together to prevent electrostatic damage. Each power
source is supplied with six jumper plugs that mate to the IGBT
Gate / Emitter Plug.
CAUTION
Electrostatic Discharge Hazard
Electrostatic discharge may damage these components.
• Damageisaccumulativeandmayonlyappearasshortenedcompo-
nentlifeandnotasacatastrophicfailure.
• Wearaprotectivegroundstrapwhenhandlingtopreventdamage
toPCBcomponents.
• Alwaysplaceapcboardinastatic-freebagwhennotinstalled.
CAUTION
The module gate plugs must be plugged into the PWM/Gate
Drive PC Board whenever the power source is in operation.
Failure to plug them in will result in damage to the module and
possible damage to the torch.
CAUTION
REMOVAL:
A. Insurethatinputpowerisremovedbytwoactionssuchasadisconnectswitchandremovaloffuses.Tagandlockany
disconnectswitchtopreventaccidentalactivation.
B. Removethetoppaneltogainaccesstothemoduleslocatedinthetoprearofthepowersource.
C. Cleanthecompartmentcontainingthemoduleswithdry,oil-freecompressedair.
D. UnplugthegatedriveleadsconnectingtheIGBTGatestothePWM/GateDrivePCBoard.Inordertopreventdamage
totheIGBT,installjumperplugsintotheIGBTGateDriveConnector.SeeCautionbelow.Jumperplugsaresupplied
witheachpowersource.
E. RemovethecopperbussplatesandbarsconnectedtotheIGBT’s.SavetheM6hardwareconnectingthebusstructure
tothemoduleterminals.Youmayneedtore-usethehardware.Longerhardwarecandamagethemodulebycontact-
ingthecircuitrydirectlybelowtheterminals.
F. RemovetheM6hardwaremountingthemodulestotheheatsink.Savethehardwarebecauseyoumayneedtore-use
it.HardwaretooshortcanstripthethreadsintheAluminumheatsink.Hardwaretoolongcanhitthebottomofthe
holescausingthemodulestohaveinsucientthermalcontacttotheheatsink.Hardwaretoolongortooshortcan
causemoduledamageduetooverheating.