Operation
SCZF1 SSR Power Controller
8
Ametek HDR Power Systems
Rev 2
a setup be required use the following methods. (Note: Adjustments requires a jeweler’s screw driver
for multi-turn bias & gain adjustments.) If using voltage input remove jumper in Figure 3.1.
The output voltage linearity for any given command is affected by the setting of the Zero and Span
adjustments.
a. Set
the
ZERO
and
SPAN
controls fully CCW (counterclockwise). .
b. Connect a voltmeter across terminals LINE and LOAD of the SCZF1. Set the voltmeter range to
measure full input voltage.
c. Close the fused disconnect or circuit breaker to apply power to the SCZF1. Turn the Process
controller on and set to demand zero power output or remote potentiometer fully CCW.
d. Adjust
the
ZERO
control CW until the output just turns on, then turn the
ZERO
control CCW just to
the point where the output voltage reading is zero.
e. Set the Process controller to demand 100% output. Observing the voltmeter, adjust
SPAN
CW
just to the point where the reading is below the maximum output voltage. Then adjust
SPAN
CW
just to the point where the meter reading is at maximum.
Note: The output voltage measurement on Zero Fired Power Controllers with a digital voltmeter
will be erratic except at full output. This is due to the variable pulses to regulate the output.
f. Repeat steps 3.5d through 3.5e as necessary, to ensure proper control adjustments have been
made.
g. Turn off the line power to the SCZF1 and disconnect the test equipment. The SCZF1 is now ready
for operation.
3.6
Remote Manual Control with a Potentiometer
Some applications only require a manual control input and not a closed loop input from a process
controller. This potentiometer may be located on a remote panel near other controls related to the
process being powered by the SCZF1. It may be calibrated to correspond to a percentage of rated
power output, process temperature, or some other parameter. The potentiometer may by 500
Ω
to 5
k
Ω
, and should be rated at 1/2 watt, minimum.
a. With the power to the SCZF1 turned off, connect the potentiometer as shown in Figure 2.2. The
CW position is the full power output position.
b. Remove jumper next to Span potentiometer, Reference Figure 3.1.
c. Set
the
SPAN
control and remote potentiometer fully CCW.
d. Connect a voltmeter across terminals LINE and LOAD of the SCZF1. Set the voltmeter range to
measure the full output voltage.
e. Close the fused disconnect or circuit breaker to apply power to the SCZF1. The unit should be
energized, with no output.
f. Adjust
the
ZERO
control CW until the output just turns on, then turn the
ZERO
control CCW just to
the point where the output voltage reading is zero.
g. Set
the
SPAN
control and remote potentiometer fully CW. The output should be full-on.
