Tweco 300 XT Ultra-Cut Plasma Cutting System - Manual (Page 84)

ULTRA-CUT 300 XT
4-20 OPERATION Manual 0-5274
4.08 Remote Arc Starter Trouble Shooting
Arc Starter Trouble Shooting
Symptom Cause Check Remedy
No Pilot ignition
Neon indicator on
Cap board lights
but no ignition.
Pilot return wire not connected
at torch head or broken in torch
lead
Visual inspection, continuity check Connect Wire or replace leads.
Coolant has become conductive Use conductivity meter
Flush system,
replace coolant.
High Frequency cap (C4 on
Cap PCB) possibly open wires
disconnected.
Use capacitance meter Reconnect or replace.
Negative supply cable not con-
nected correctly
Visual inspection Reconnect
Pilot return wire not connected
or loose in arcstarter.
Visual inspection Connect Wire.
No Pilot ignition:
Neon indicator
not illuminated.
No 120V supply, CB4 of plasma
rear panel tripped
Reset breaker, check for 120 VAC
at the module’s 115V terminals
during ignition time.
Check for shorted cable, defec-
tive circuit breaker, shorted
ignition module input. (see
next symptom)
Electronic Ignition module
shorted input
Resistance measurement, good
module measures about 45 ohms
Replace bad module
No 120V supply, CB4 not
tripped
check for 120 VAC at the plasma
supply’s rear panel connector J59-
7 & 9 during ignition time.
120V present - open control
cable, 120V not present - fault
in plasma power supply
Faulty Electronic Ignition
module
Check for 120 VAC at the modules
115V terminals during pilot igni-
tion time
If 120 VAC is present but neon
not illuminated, module is
defective, replace module
Loose fitting(s) Visual inspection Tighten fittings.
Coolant Leaks
Damaged or punctured coolant
line(s).
Visual inspection Replace Coolant Lines
Supply & return hose reversed
Visual Inspection of color-coded
connections
Match coolant connection
colors
to arc starter fitting colors.
No cooling or
insuf¬ficient cool-
ing: No Coolant
Flow
Blockage in supply/return hoses Loosen fitting slightly and check
for coolant flow
Flush system or replace
blocked hose.
Missing or loose
ground connection
Visual inspection of ground wire
to Arc Starter
Make or tighten connections to
good ground.
Erratic System
Behavior(EMI
Interference
Torch Lead Shield not connected
or loose. F1 gnd cable not con-
nected.
Visual inspection of lead shield
attachment to Arc Starter
Reconnect / tighten lead con-
nectors.
Cap board ground screw not
tight or missing.
Visual inspection Tighten or replace.
Cap C5 or C7 (on Cap PCB) open
or disconnected wires to Cap
board.
Visual inspection / capacitor
measurement
Replace PCB.