Thermal Dynamics SIGNATURE PAK 1250XRTM, Owner'S Manual

Page: 46 / 68

34
SERVICE
Once the cutting arc is established it should remain on until the torch control switch is released
or the torch is moved away from the metal enough to break the arc (pilot arc should re-ignite).
TROUBLE POSSIBLE CAUSE REMEDY
N. Unit shuts down during
cutting operation and:
a. TEMP indicator not lit
b. GAS indicator not lit
c. AC indicator not lit
O. Low output and/or poor
cut quality in high range,
no or low output in
medium and low range
1. Transformer overheated
2. Gas supply pressure too
low
3. Loss of primary power
4. Blown fuse (1FU)
1. Shorted bridge diode on
transformer having low
output
2. Faulty contactor W1, W2,
or W3
3. Faulty range switch SW3
1. Allow unit to cool.
2. Check and correct .
3. Check primary power
source.
4. Replace fuses.
1. Check diode (See E, page
35).
2. Check contactors and
replace if necessary.
3. Check switch and replace
if necessary.
If the torch parts life is short, check:
TROUBLE POSSIBLE CAUSE REMEDY
P. Short torch parts life
Q. Excessive tip deteriora-
tion occurs
R. Arcing in electrode seat
area
1. Incorrect gas pressures
2. Misuse of torch
3. Contaminated (dirty) gas
4. HF relay remains on
during cut
5. No pre-flow gas flow (two
seconds)
6. No post-flow gas flow (ten
seconds)
1. Replacement contactors
not installed correctly
1. Electrode not tight
1. Check and correct.
2. Use torch within ratings.
3. Install filter.
4. Replace control logic PC
board.
5. Check and correct.
6. Replace PC board.
1. Check wire orientation
(see I, page 36).
1. Tighten electrode.
4.4 TROUBLESHOOTING GUIDE (continued)