Service Manual 0-2717
13
COUGAR 125 Plasma Cutter
If the Gas Solenoid energizes and gas flows
intermittently and arcing can be seen in the Re-
lay Case while the torch switch is held on, the
Relay contacts are worn and the Relay should
be replaced.
7. Faulty Gas Solenoid
Check for 12 VDC (momentarily) between So-
lenoid wires #11 & 21. Replace Solenoid if volt-
age momentarily jumps to 12VDC with torch
switch pressed.
F. Power OK, Fan runs, Solenoid runs
intermittently, Relay Case shows
arcing when the torch switch is held
on.
1. Faulty Relay.
a. If the Solenoid opens intermittently and arcing
can be seen in the Relay Case while the torch
switch is held on, the Relay contacts are worn
and the Relay should be replaced.
G. Power OK, fan runs, Solenoid opens
then closes as soon as the torch switch
is pressed.
1. Shorted, damaged, or incorrect torch parts.
a. Check that all torch parts are in good condition
and designed for use in the PCH-10 torch.
2. Faulty (open) Voltage Divider Resistor.
a. The voltage divider is the top Resistor. Discon-
nect the push-on connectors and measure the
Resistor with an ohmmeter. It should read 1K
ohms. If measurement is not 1K ohms, replace
Resistor.
3. Shorted Bridge Rectifier (BR1).
a. Probable if a loud hum or buzz is heard from
the main Transformer after the Relay actuates.
If hum or buzzing noise exists, replace Bridge
Rectifier. (replace lower Bridge Rectifier, clos-
est to Chassis).
H. Power OK, fan runs, air flows, no pilot
or cutting arc with the torch switch
pressed.
1. Worn, contaminated, or incorrect torch parts.
a. Check that all torch parts are in good condition
and designed for use in the PCH-10 torch. Re-
place worn parts as necessary.
2. Parts not assembled correctly.
a. Reassemble torch parts.
3. Damaged torch or leads.
a. Check per subsection 3.6, Torch and Leads
Troubleshooting.
4. Faulty Control PCB.
a. Listen for a faint, sharp clicking noise, at about
3-4 clicks/second from the Ferrite Core Assem-
bly. If nothing is heard, the PCB should be re-
placed.
5. Faulty (open) Pilot Resistor.
a. The Pilot Resistor is mounted closest to the chas-
sis. Disconnect the push on connectors and
measure the resistor with an ohmmeter. It
should read 0.5 ohms (essentially a short).
6. AC input too low.
a. If the AC line is below about 105vac, the torch
may not always start. Try an outlet on a differ-
ent branch circuit.
7. Faulty Ferrite/Transformer Assembly.
a. The Ferrite Transformer Assembly is used to
generate a high voltage pulse to establish the
pilot arc. Troubleshooting is limited to visual
inspection. The two primary connections and
two secondary connections should be checked
for general integrity and snug fit onto the push
on connectors. The Transformer Assembly it-
self should be free of large ferrite chips and
cracks along the core.
I. Torch pilots but does not cut well.
1. AC input power too low.
a. Use shortest service from AC outlet to breaker
panel as possible or larger gauge extension cord.
2. Work cable not attached.
a. Check work cable connection.
3. Restricted air flow.
a. Check lead for kinks or pinching restricting air
flow.
4. Loose shield cup.
a. Tighten shield cup.
5. One or more gas distributor holes blocked.
a. Replace Gas Distributor.
6. Excessive parts wear.
a. Inspect torch consumables and replace as nec-
essary.
