ESAB Plasmarc EPP-450 - Power Shunt Installation

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6.4.3 Power Shunt Installation
Instability or oscillation in cutting current can be caused by im-
proper dressing of shunt pick-up leads.
Poor torch consumable life will be the result.
CAUTION
Terminals parallel
tobusbars
Therearetwocablesthatattachtotheshuntpick-uppoints:
atwoconductorcabledrivestheammeter
athreeconductorwhichprovidesthecurrentfeedbacksignaltoPCB1(controlPCB).
Dressingofthe2conductorcableisnotcritical.
Thefollowingisthedressingprocedureforthe3conductorcable.
• Thebreakoutpointshouldbephysicallyatthemiddleoftheshunt.Thebreakoutpointistheplace
wheretheconductorsexitfromtheouterinsulationjacket.
• Theblackandclearinsulatedwiresmustbekeptnexttotheshuntandunderthecableties.
• Thewireterminalsfortheblackandclearinsulatedwiresshouldbeorientedinparallelwithbusbars
asshown.
SECTION 6 TROUBLESHOOTING
clearinsulation
twoleads
threeleads
• It is important to have the barrels of the black
and clear insulated wires, from the three lead
cable,bepointinginoppositedirections.
• Thethirdwireattachestothebusbarontheleft
withtheshuntmountinghardware.Orientation
ofthiswireisnotcritical.