Tweco SC11 - Manual (Page 30)

CUSTOMER/OPERATOR SERVICE 5-2 Manual 0-2556
5.04 Troubleshooting Specific
Problems
A. Front panel switch for MODE, LIFTER
SPEED, TORCH UP or TORCH DOWN will
not function
1. Connector J3 on the Standoff Control PC Board is con-
nected one pin off
a. Make sure connector is plugged in correctly.
2. Faulty front panel switch or Standoff Control PC Board
a. Test per Section 5.05-B and replace faulty as-
sembly as required
3. External power source not connected or turned ON
a. Verify +48 volt external power source is con-
nected and turned ON
B. One or more, not all, front panel indicators will
not turn ON when expected
1. Faulty indicator or Standoff Control PC Board
a. Test per Section 5.05-C and replace front panel
assembly if necessary
C. Torch will not move up or down manually using
TORCH UP and TORCH DOWN switches;
TORCH UP and TORCH DOWN indicators come
ON
1. Torch Lifter Assembly rack and pinion gear misaligned
or not meshing
a. Lift up on the torch while pressing the TORCH
UP arrow to remesh the gears.
2. Dirty Lifter Slide or Rollers
a. Remove cover and clean Slide and Rollers
3. Mounting screw of Torch Lead Support Bracket too long
a. Replace with shorter screw
NOTE
The mounting bolts attaching the torch lead sup-
port bracket to the Torch Lifter Assembly can bind
if the mounting bolts are too long.
D. Torch will not move or no pilot arc when START is
pressed
Push front panel TORCH UP or TORCH DOWN
switch to see if torch will move manually. If torch
will move in either direction, then torch lifter motor
and cable are okay.
1. Check for binding of the torch lifter assembly slide.
a. Repair as required
NOTE
The mounting bolts attaching the torch lead sup-
port bracket to the Torch Lifter Assembly can bind
if the mounting bolts are too long.
2. Faulty torch lifter motor, cable or start circuit
a. Check the motor and cable per Section 5.05-D,
repair as necessary
E. Torch moves down to work but does not retract to
PIERCE HT setting
1. PIERCE HT control is set fully counterclockwise
(CCW), minimum standoff
a. Adjust for higher standoff
2. Tip-On-Work micro-switch faulty, out of adjustment
or slide frozen so switch cannot be activated
a. Check the Tip-On-Work micro-switch per Sec-
tion 5.05-E, repair as necessary
F. Torch moves down to the work and retracts, but
stops at a point higher than the PIERCE HT
setting or continues to a point at the top of travel;
Pilot may activate when the travel stops
1. Tip-On-Work micro-switch circuit is faulty or have
dirty contacts
a. Check the Tip-On-Work micro-switch per Sec-
tion 5.05-E, repair as necessary
G. Torch moves up instead of down when it should
be finding height
1. Tip-On-Work micro-switch circuit is open
a. Check the Tip-On-Work micro-switch per Sec-
tion 5.05-E, repair as necessary
H. Torch finds height and starts cutting but cutting
machine doesn’t move
1. Motion (OK-To-Move) signal not compatible with cut-
ting machine controller. Signal set for contacts, but
controller needs AC volts or vice versa.
a. Change setting per Section 3.09-B.
2. Faulty motion (OK-To-Move) signal from Plasma
Power Supply
a. Check for proper motion (OK-To-Move) signal
per Section 5.05-F, repair as necessary
I. After cutting starts torch remains at initial height;
THC ACTIVE indicator is OFF
1. Automatic find height not activated, AUTO HT indi-
cator OFF
a. Press MODE control switch until AUTO HT in-
dicator comes ON