Thermal Arc ULTIMA 150, Service Manual

Page: 31 / 64

Manual 0-2503 25 SECTION 4: REPAIRS & REPLACEMENT
SECTION 4:
REPAIRS & REPLACEMENT
4.01 Introduction
This section describes parts replacement procedures and
all cable repairs that may be performed on the ULTIMA-
150 Plasma Welding Power Supply.
WARNING
Under no circumstances are field repairs to be at-
tempted on Printed Circuit Board or other subas-
semblies of this unit. Evidence of unauthorized
repairs may void the factory warranty.
4.02 General Anti-Static Handling
Procedures
A. General
CAUTION
PC Boards can be irreparably damaged by improper
handling due to electrostatic discharge (ESD).
Replacement PC Boards are shipped in protective
enclosures to prevent damage from electrostatic dis-
charge (ESD) during shipping. Included with each
replacement board is a ground strap to prevent
static damage during installation.
WARNINGS
Read and understand these instructions and the
instructions on the grounding wrist strap package
before opening the unit enclosure or removing the
replacement PC Board from its protective enclo-
sure.
Disconnect primary power to the system before dis-
assembling the unit or any external connections.
Do not operate the unit or test equipment under
power while wearing the grounding wrist strap.
B. Procedure
1. Open the wrist strap and unwrap the first two
folds of the band. Wrap the adhesive side firmly
around your wrist.
2. Unroll the rest of the band and peel the liner from
the copper foil at the opposite end.
3. Attach the copper foil to a convenient and exposed
electrical ground.
4. Connect the wrist strap to the same electrical
ground as the unit ground.
5. Open the unit enclosure and remove the failed
PC Board.
6. Carefully open the ESD protective bag and re-
move the replacement PC Board.
7. Install the replacement PC Board in the unit and
make all necessary connections.
8. Place the failed PC Board in the ESD protective
bag and seal for return shipping.
9. Reassemble the unit enclosure.
10. Remove the grounding wrist strap from your
wrist and from the electrical ground connection
before reconnecting primary power to the unit.
4.03 Parts Replacement - General
Information
The parts replacement procedures described in this
manual, with the exception of filter replacement, require
some disassembly. Before disassembling any part of the
ULTIMA-150 Power Supply first read the procedure for
the part to be replaced, then proceed with the disassem-
bly.
WARNING
Repairing this unit is a process which should be
undertaken only by those familiar with high volt-
age power electronic equipment.
WARNING
Disconnect primary power from the source before
disassembling the power supply, opening modules
or replacing parts on modules. Make sure AC in-
dicators on the ULTIMA-150 Power Supply front
panel is not ON.