Tweco 3000 Merlin - Manual (Page 47)

Manual 0-2532 5-3 SERVICE
5.04 Troubleshooting
General
Troubleshooting and repairing the this unit is a process
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
had training in power electronics measurement
and troubleshooting techniques.
Basic Troubleshooting
This manual covers a basic level of troubleshooting that
requires limited disassembly and measurements. It is
helpful for solving many of the common problems that
can arise with a plasma cutting system.
NOTE
For major troubleshooting and parts replace-
ment procedures refer to Power Supply Ser-
vice Manual 0-2533.
If major complex subassemblies are faulty, the unit must
be returned to an authorized service center for repair.
Follow all instructions as listed and complete each sec-
tion of the troubleshooting guide in the order presented.
How to use this Guide
The following information is a guide to help the Customer/
Operator determine the most likely causes for various
symptoms.
This guide is set up in the following manner:
X. Symptom (Bold Type)
Any Special Instructions (Text Type)
1. Cause (Italic Type)
a. Check/Remedy (Text Type)
Locate your symptom, check the causes (easiest listed
first) then remedies. Repair as needed being sure to
verify that unit is fully operational after any repairs.
Troubleshooting Specific Problems
A. Main disconnect fuse blows when primary
power is connected
1. Voltage selection busbars connected incorrectly
a. Check and correct if necessary.
2. One leg of three-phase primary connected to chas-
sis ground
a. Rewire input cable
3. Faulty power supply
a. Isolate and replace component(s) per Service
Manual.
B. AC Power Indicator on Front Panel not ON; Fan
and pump OFF
1. Customer’s main power disconnect is turned OFF
a. Turn ON main power disconnect
2. Front Panel ON/OFF switch is turned OFF
a. Turn ON front panel power switch
3. No primary power
a. Check for proper three-phase power at input
terminal board
4. Blown fuse (F2)
a. Check and replace fuse if necessary
5. Faulty power supply
a. Isolate and replace component(s) per Service
Manual.
C. AC power indicator ON; Fan and pump OFF
1. Remote Control or TB2 Enable switch not ON
a. Turn ON switch or enable signal at TB2
2. Primary power - missing phase
a. Check for proper three-phase power at input
terminal board
3. Blown fuse (F1 or F2)
a. Check and replace fuse if necessary
4. Faulty power supply
a. Isolate and replace component(s) per Service
Manual