Tweco N7500 - Manual (Page 51)

Manual 89250890 8-3 TROUBLESHOOTING GUIDE
TROUBLESHOOTING GUIDE N7500
Torch Head
Problem Possible Cause Possible Remedy
Air leaking
from Air Ple-
num Housing
O-rings on Air Plenum supply tube
worn
Check air tube o-rings, replace if necessary.
Top assembly of Air Plenum Hous-
ing not fastened securely to lower
Air Plenum Housing
Tighten screws on Plenum.
Top assembly of Air Plenum Hous-
ing is distorted from excessive heat Replace.
Busbar corro-
sion, arcing,
overheating,
or screws
loose inside
head
Cable connections are NOT wrench
tight
Tighten busbar leads connection wrench tight.
Electrode
short out
DC Voltage setting is incorrect Adjust DC voltage to 40 to 44 DC Volts.
Current set too low for electrode
being used
Adjust DC current.
Arc out on air nozzle or the elec-
trode guide block
If NO signs of arcing are present, retry starting the gouge
procedure by pressing the “Start” button on the Pendant.
If signs of arcing are present, repair or replace compo-
nents. See "Figure 9-3: Torch Head PARTS" on page 9-2.
Electrode
retracts during
normal opera-
tion
Power supply and N7500 not on
same CC/CV setting
Reset both to the same CC or CV setting.
DC Voltage setting is incorrect Adjust DC voltage to 40 to 44 volts.
STOP button pushed Press START button.
Electrode does
not retract
Torch Head motor not working Check Torch Head motor and cable. Repair or replace.
Joint separated
or
Electrode stub jammed inside
housing
Realign electrodes or replace damaged electrode.
Shut N7500 down, disconnect Torch Head from Control
Box, open housing cover plate and remove electrode. See
"Figure 9-3: Torch Head PARTS" on page 9-2.
Electrode does
not retract
and reposition
itself at start
up
Torch Head Motor Cable not at-
tached or improperly attached
Attach motor cable.
Electrode does
not arc
No or low current
Check the Power Supply current output.
Adjust the Power Supply output current to match the rated
current for the Electrode size. Refer to "Table 5-5: Param-
eter Table" on page 5-4.
Table 8-3: Torch Head Troubleshooting