Watlow QPAC Modular SCR Power Control Service - Manual (Page 27)

WATLOW QPAC Service Manual 27 Troubleshooting, Chapter 5
Bench Testing
QPAC-01
Single Phase
Load
T2
T1
L2
L1
T1
Control Card
+ -
AC
Command Signa
4-20mA or
0-5VDC
QPAC-33
3 Phase
Load
T3
L3
T2
L2
T1
L1
T1
Control Card
+ -
AC
Command Signa
4-20mA or
0-5VDC
QPAC-32
3 Phase
Load
T3
T2
T1
L3
L2
L1
T1
Control Card
+ -
AC
Command Signa
4-20mA or
0-5VDC
Bench Testing Hookups
Equipment Required
• Dummy Load, min. 1A
• 0-15VDC Command (signal)
or
❋
NOTE:
Dummy loads can
be made up using
100 watt light bulbs.
Bulbs can be put in
series to obtain the
proper voltage rat-
ing. (4each, 100
watt, 120V bulbs
per phase for 480V)
An SCR will not
latch without a
load.
❋