Precision Control Systems 1029C - Manual (Page 18)

MODEL 1029C 14 10/19/2007
ADJUSTMENTS
The I Span and V Span pots (and Power
Span and Power Zero pots, when factory
installed), are sealed at the factory. They are
identified with an X in Figure 17 . Under no
circumstances should adjustment of these
four pots be attempted.
The setting of each of these potentiometers is critical
to the proper operation of the controller.
The potentiometers labeled Run Span, Run Zero, Idle
Span & Idle Zero have been calibrated at the factory and
readjustment should not be necessary.
The zero pots are adjusted to provide zero output when
the command signal is at minimum. The span pots are
adjusted to provide full output when the command signal is
at maximum.
If it is determined that the adjustment should be changed,
the following procedure should be followed:
It is assumed that the load is resistive and can draw at least
one or more amps.
Run Zero and Run Span:
Determine that pin P1-11 (Run/Idle) is electrically
connected to pin P1-10 (Common). Make sure that the
command signal is connected between the Run input P1-13
(Run/Wiper) and P1-14 (Common).
1. Set the command signal to minimum and adjust the Run
zero potentiometer until the output is zero.
2. Set the command signal to maximum and adjust the
Run span potentiometer until the output is at the desired
maximum value.
3. The span and zero adjustments may interact, making it
necessary to repeat steps 1 and 2.
Idle Zero and Idle Span:
Remove the electrical connection from between P1-11
(Run/Idle) and P1-10 (Common). Make sure that the
command signal is connected between the Idle input P1-15
(Idle/Wiper) and P1-14 (Common). Repeat steps 1,2 and 3
(above) on the idle zero and span potentiometers.
It is important that meters capable of
accurately measuring the output of the
controller be used.
True RMS meters should be used for accurate
measurements of True RMS Voltage, Current or
Power (RMS Volts times RMS current into a resistive
load).
Average responding meters should be used for
measurements of;
Average AC Voltage or DC voltage.
Current Limit:
(The current limit pot is factory set at 105% of rated current
unless specified differently by the ( IL) term in the model
Number.)
Proper calibration of the current limit feature requires a
True RMS current meter.
If it becomes desirable to reset the current limit level:
1. Rotate the current limit pot fully counter- clockwise.
(This is a multiple turn pot.)
2. Carefully increase the command signal to maximum.
3. Slowly rotate the current limit pot in a clockwise
direction until the desired load current is reached.
If it is suspected that the current limit adjustment is causing
the output of the controller to be lower than desired, rotate
the current limit pot clockwise. If the load voltage increases,
the current limit adjustment has been controlling the output.
Follow the steps above to set current limit to the desired
level.
OVER CURRENT TRIP:
This potentiometer has been factory set at 150% of rated
frame current. For optimum protection, the customer may
wish to reduce the level at which Over Current Trip occurs.
1. Adjust command signal to maximum.
2. Slowly rotate the Over Current Trip pot counterclockwise
until the Over current Trip occurs.
3. Rotate the Over Current Trip pot about 1/2 turn
clockwise.
4. Reset the Over Current Trip circuit.