Advanced Troubleshooting; System-Level Fault Isolation; Opening The Enclosure - Thermal Arc ARCMASTER 200 TS Service Manual

11

ADVANCED TROUBLESHOOTING

If you are here, all of the troubleshooting sugges-
tions in Section 8 - Basic Troubleshooting have either
failed to resolve the faulty operation or have indi-
cated that one or more of the subsystems within
the power supply are defective. This section pro-
vides the information needed to take live measure-
ments on the various subsystems within the power
supply, and replace those subsystems that prove
faulty.
CAUTION
Troubleshooting and repairing this unit is a pro-
cess, which should be undertaken only by those
familiar with high voltage/high power electronic
equipment.
WARNING
There are extremely dangerous voltage and power
levels present inside this unit. Do not attempt to
diagnose or repair unless you have training in
power electronics, measurement and troubleshoot-
ing techniques.
Under no circumstances are field repairs to be
attempted on printed circuit boards or other subas-
semblies of this unit. Evidence of unauthorized
repairs will void the factory warranty. If a subas-
sembly is found to be defective by executing any of
the procedures in this Service Manual, the subas-
sembly should be replaced with a new one. The
faulty subassembly should then be returned to
Thermal Arc through established procedures.
WARNING
Disconnect primary power at the source before dis-
assembling the power supply. Frequently review
the "Important Safety Precautions" in section 1.02.
Be sure the operator is equipped with proper
gloves, clothing and eye and ear protection. Make
sure no part of the operator's body comes into con-
tact with the work piece or any internal components
while the unit is activated.
1
System-Level Fault Isola-
ADVANCED TROUBLESHOOTING
tion
If none of the suggestions provided in Section 8
have solved the problem or corrected the faulty
operation, the next step is to isolate one or more of
the internal subassemblies that may be defective.
CAUTION
Perform all steps in each procedure, in sequence.
Skipping portions of procedures, or performing
steps out of sequence can result in damage to the
unit, and possible injury, or worse, to the operator.

1.1 Opening the Enclosure

1) Verify that the switch of power supply and the
switch on switchboard (distribution panel) are
all OFF.
CAUTION
The capacitors inside the power supply will slowly
discharged after you turn off the switch of the
power supply or the switch at the breaker box (dis-
tribution panel). Wait at least 5 minutes for the dis-
charge to complete.
2) Remove all screws and nuts on the side pan-
els.
11 – 1
Figure 11-1: Switch OFF
Figure 11-2: Remove screws