Troubleshooting Tables - Hobart 6T28-600CL Operation And Maintenance Manual

OM-2244 / Operation and Maintenance Manual
DCS-600/ Series 500082 / Solid State Transformer-Rectifiers
If no Oscilloscope is available: Remove all six service fuses next to the A1 PC board. Keep in mind during
this test only one fuse at a time will be placed in the holder with the with fuses other removed.
CAUTION

Systematically put only one fuse in it's holder at a time and turn the input power switch on and see if 28.5VDC
Is indicated on the Ground Power Unit Voltmeter. If voltage is present at the voltmeter then that particular
SCR(Diode) is good. Continue putting one Fuse at a time in it's holder to check if the 28.5 VDC is present at
the voltmeter , do this until all six fuse holders (SCR) have been checked. If a particular fuse placed in its
holder (again no other fuses installed) does not indicate 28.5 VDC the SCR or that circuit has failed.

6) Troubleshooting Tables

Trouble, Symptom, Condition
Machine Will Not Operate
1. Machine will not start
2. Line contactor fails to close
December 15, 2014
The input power switch should be off whilst removing and installing
each fuse for this Test
Probable Cause
a. The input power is turned OFF
at remote disconnect switch
b. Blown fuse in remote disconnect
switch
c. Incorrect input power
connections at machine
d. Incorrect power input (frequency
and voltage)
e. Broken input cable
a. Line contactor fuse F8 blown
b. Mechanical obstruction on
contactor
c. Defective line contactor switch
d. Defective coil in line contactor
e. Cable broken at line contactor
Test, Check, and/or Remedy
Turn the power ON at remote
disconnect switch.
Replace blown fuse. If fuse blows
frequently, determine and remedy
the cause.
Check input power connections
against appropriate connection
diagram in Chapter 5.
Check that voltage and frequency
of power input for this ground
power unit, according to the rating
on its nameplate.
Repair cable as necessary.
Replace fuse. Check for cause if
fuse blows frequently.
Remove obstruction.
Replace line contactor switch.
Replace contactor if coil is open or
shorted.
Repair broken cable as necessary.
Chapter 2-1
Page 5