Precision Control Systems 3629C - Manual (Page 22)

MODEL 3629C 18 04/10/2007
ADJUSTMENTS
The zero and span potentiometers are factory set, and generally do not require further adjustment.
If adjustments become necessary, the following procedure should be followed.
If you are using RMS feedback, you must use a true RMS meter for these measurements.
1. Set the command signal to minimum and adjust the zero potentiometer until the output is zero. If this pot is set
incorrectly, the output of the controller may not be linear with respect to the command signal, or, the controller may be
unable to shut off completely.
2. Set the command signal to maximum and adjust the span potentiometer until the output is at the desired maximum
value. If this pot is set incorrectly, the output of the controller may not be linear with respect to the command signal, or,
the controller may be unable to reach full output.
3. The span and zero adjustments may interact, therefore it may be necessary to repeat steps 1 and 2.
Current limit potentiometer adjustment.
To monitor the Current Limit Adjustment, apply the negative lead of your multimeter to terminal 14 of the command
connector, and the positive lead to terminal 17. See Figure 22 .
Rotating the Current Limit potentiometer clockwise increases the value to which the load current is limited. Negative 1Volt
= 100% of frame current.
Over Current Trip potentiometer adjustment.
To monitor the Over Current trip Adjustment, apply the negative lead of your multimeter to terminal 14 of the command
connector, and the positive lead to terminal 18. See Figure 21 .
Rotating the Over Current Trip potentiometer clockwise increases the value at which the Over Current Trip circuit will
activate. Positive 1Volt = 100% of frame current.
(+5) CW
OVER
CURRENT
RELAY
SHORTED
SCR
RELAY
READY
COMMON
RESET
I LIMIT
EXT. FB.
(+) W
O.C.T.
(- ) CCW
-5 VOLT
TI
MI
L
OR
EZ
NA
PS
TC
O
C
L
O
RT
N
O
C
N
O
C
ST
PE
D
RE
G
N
A H
GI
H
E
G
AT
L
OV
O
M
D
C9
26
3
LE
Figure 29. Lid of 3629C showing adjustment locations.