GE DC-30311 Installation Operation & Maintenance page 50

TABLE 6-2
Indication
Motor/Machine
unstable!
erratic
(con'd)
DRIVE SYSTEM OPERATING
Check/Adjust/Replace
4.
Check speed reference input for noise pickup
(with scope).
5. Check tach feedback signal for noise.
6.
Check current feedback signal for noise.
7.
8.
9.
NOTE
THE FOLLOWING LEADS SHOULD
BE TWISTED PAIRS: REFERENCE
INPUT, TACH AND CURRENT FEED-
BACKS.
Adjust the ffResponse" pot slightly CCW.
Using the scope, check for noise on the
following test points:
a. Incoming reference.
b. Timing output.
c. +Driver References.
d. Driver Coordin&tion output.
e.
f.
g.
Common.
Lockouts 1 and 2.
+20VDC.
Using the scope,
proper width and
check the following signals for
time relationship to each other:
1 .... 180°-..:
~
/"1/"1
' - - - 360
0
.. I
I
I
I I
I
I
I
I
I
I
I
I
~
I
I
I
I
I
~
I
I
~
6-8
TRP
at
a
UJT EMIT #: I
It II
# 2.
II
n :;;:
3
TRIG #: I
II
:#=2.
It
'*
3
FIRING #: I
OR 4
"
#: 2. OR 5
" :II: 3 OR 6