GE DC-30311 Installation Operation & Maintenance page 43

6.1 GENERAL
SECTION VI
TROUBLESHOOTING
These trouhleshooting procedures assume that the system has been
installed and checked out and has been operating properly prior to a
malfunction. Fast efficient troubleshooting of the drive system is
based on a thorough knowledge of the theory of operation plus well
kept maintenance records that will provide trend data indicating the
possible area of the problem. All measurements should be compared
with checkout values. If temporary malfunctions/problems occur,that
seem to disappear or self-correct themselves, the incoming three
phase a-c power should be checked for proper amplitude and phase at
times of peak loading in the facility/building. Should repeated fuse
and/or SCR failures occur, the three phase a-c input power should be
checked for high level spikes or extreme short duration power varia-
tions. During troubleshooting when a card or subassembly is found
or suspected of being bad, it is recommended that prior to replacing
the card/subassembly the inputs be checked for proper v?lues. This
will exclude the chance of further damage to the replacement item
due to causes beyond the suspected item. If line fuses or SCR's have
failed, it is recommended that the power conversion module be dis-
connected by placing SWI to C, and the system test, Section IV, be
used to check for proper operation prior to connGCting up the power
conversion module after failed components are replaced and power is
reapplied.
6.1.1
Electrical
The electrical troubleshooting procedures are divided into
three parts; Drive Systems operating but not properly,
Qrive Systems not operating, and Drive Systems stopped
while running. The following checklists, in conjunction
with logical problem analysis, will help locate the
malfunction with a minimum of effort. Use the Functional
Flow Diagram (Figure 9-1) when analyzing the problem.
If in troubleshooting the inputs are found
to be good but the outputs are bad, then the malfunction
is assumed to be located. To use the checklist correctly,
first select the proper checklist depending on the type
malfunction indicated - Operating or Not Operating. Using
this checklist, locate the type of malfunction indicated
under the left-hand column, "Indic.ation". The right-hand
column "Check/Adjust/Replace" lists, in logical order, the
steps to be taken. When a step or action is completed and
the malfunction still occurs, proceed to the next step.
If the step located the problem area, troubleshoot, isolate
and correct the malfunction. Retune/Adjust as required
using Section IV.
6-1