Precision Control Systems 930 - Manual (Page 21)

Model 930 ControlIR TM Instruction Manual Maintenance and Trouble Shooting
Research, Inc. Page 17 of 25
CALIBRATION
Power Controller
Symptom Action
No output to load, heaters
or lamps. Setpoint switch
is in REMOTE. Opera-
tion O.K. with Setpoint
switch in LOCAL (if not
see above). 1. Verify the polarity of the remote input. TB 100 pin
16 is positive, and 17 is negative.
2. Units with Temperature control option: Place
temperature controller in manual mode with 50
percent output. Verify 2.5VDC at TB 100 pins 16
and 17. Refer to the temperature controller manual
regarding repairs.
Full voltage cannot be
obtained. 1. Verify the load, lamps, or heaters are not drawing
current at full capacity of the system. Rotate the
current limit pot on the power controller 1 turn
counterclockwise. If the load current decreases, the
current limit is controlling the output.
2. Verify the line voltage. Load voltage maximum is
approximately 98 percent of the line voltage.
3. Test in LOCAL setpoint mode. Set the ‘Local
Setpoint’ potentiometer to 900. The voltage should
be 216 (240 volt line), or 432 (480 volt line). Adjust
the RUN SPAN potentiometer of the power
controller as necessary.
4. Faulty power controller SCR or control circuit. Refer
to the power controller manual regarding repairs.
Load voltage will not go
to zero. 1. Verify the load voltage will go to zero with the SCR
switch set to DISABLED. If it does not, refer to the
power controller manual regarding repairs.
2. If the shorted SCR indicator of the power controller
is on, an SCR has failed.
3. Units with the Product Detect option: Normal
operation of the idle circuit. The idle potentiometer
maintains the voltage at idle.
4. Units with the Conveyor / Web speed option:
Normal operation. The minimum idle potentiometer
may be adjusted to lower the load voltage to zero if
the web is stopped.
Generally components of the power control system hold their calibration very well
over a long period of time. Usually verification of calibration is all that is necessary.
We suggest verification or calibration be performed on a yearly basis. Calibration
should be performed by qualified personnel as dangerous voltages are present.
Refer to the power controller manual for specific calibration instructions. Calibrate
using step 1, 2 or 3 below (use whichever is used most often):
1. When LOCAL setpoint mode is selected, the local setpoint potentiometer is used
as the source for the input. Adjust the zero and span potentiometers on the power
controller. The SPAN potentiometer is adjusted for 90 percent or rated line
voltage for 900 dial divisions of the local setpoint pot. The ZERO potentiometer is
adjusted for 0 Volts output when the local setpoint is set to 000 dial divisions.