SECTION 5
C. STATUS LIGHT TROUBLESHOOTING CHART
ROS ON
Is
OVER TEMP
Light
On?
NO
Is
READY/LOW GAS
Light
On?
YES
Set Gas(es) at proper
pressure with OSS
switch in CUT/
START-SHIELDmode.
Place OSS switch in
OPERATE
Depress Torch
Switch
Is
HIGH FREQ
Light
On?
YES
Does
LOW GAS
Light GO
Off?
YES
2 second delay
Proper Input
Power Applied
YES
1.
Machine may be overheated.
2.
Check connections to thermal switches
(TS).
1. Close top lid.
NO
2. Check ISW switch
3. Check CB1.
"A"
1. Check OSS switch.
2. Check Torch Switch.
NO
3. Check PAC contactor to insure 24 VAC
is applied to coil.
4. Check PC Board 675369.
5. Check HFTR Transformer
1. Check input gas pressure.
2. Check gas flow of PT-26. Check to be
sure consumables are good and
NO
properly in place.
3. Check torch switch for intermittent
connection.
4. If using PT-26, check jumper between
pin 4 and 5.
Does
TORCH ON
Light turn
on?
YES
Is
Pilot Arc
established
?
YES
Touch pilot arc to work piece within 6
sec. after pilot arc is established, or pi-
lot arc will turn off and begin cycling
on and off about every 3 sec..
Is
Main Arc
established
?
YES
HIGH FREQ light
goes out
Adjust cutting speed
Release torch switch
LOW GAS light
turns on
Unit in Post Flow mode
and ready to cut again.
"A"
246
MAINTENANCE
1. Check open circuit voltage.
Should be about 370 VDC.
(Disconnect HF to avoid
damaging meter.)
NO
2. Check input power.
3. Check MC contactor.
4. Check diodes and SCR's.
5. Check PC board 675468.
1. Check consumables in torch.
2. Check torch connections using
ohmmeter.
3. Check open circuit voltage (325
VDC). (Disconnect HF to avoid
NO
damaging meter.)
4. Check HF at spark gaps. (ISW
switch must be closed when
performing check.) May have to
reset spark gap.
5. Check PAC contactor.
6. Check R20 and R21 resistors.
1. Check work lead connection.
2. Check consumables in torch.
3. Check for proper nozzle and
current. At low currents, the arc
NO
length has to be closer to work.
4. Check all input voltages between
lines.
5. Check open circuit voltage.
6. Check diodes and SCR's.
7. Check PC board 675468.