Siemens 3PCI Series, Operation Manual

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Operation 3PCI SCR Power Controller Series Manual
3-2
s
Version 1.2 (19000325)
3.3. Temperature Controller
A wide range of controller outputs can be used to drive the 3PCI. The range of acceptable full scale output
voltages is from a minimum of 0-5 VDC to a maximum of 10 VDC. Since most controllers have a current
output, the input impedance of the 3PCI on
TB1-1
(-) and
TB1-2
(+) is 0.05 to 10 VDC for voltage control. For
milliamp control, connect to
TB1-1
(-) and
TB1-7
(+). Input impedance is 250
Ω
.
Although the 3PCI unit is factory set for control as specified on the unit’s decal, temperature control
calibration may be performed as follows:
1. Connect a 4-20 mA
DC
control signal to
TB1-7
(+ input) and
TB1-1
(- input) as shown in Figure 3-1.
2. Using a voltmeter to monitor output voltage, adjust the bias control until some voltage is seen. Then
adjust the bias counter-clockwise (CCW) until the output voltage is as close to zero as possible.
3. Set the temperature controller to demand 100% output. Observing the voltmeter, adjust the gain until
the voltage reading is slightly below the maximum output voltage.
4. Repeat the previous steps to ensure that the proper control adjustments have been made.
5. Turn off the line power to the 3PCI and disconnect the test equipment. The 3PCI is now ready for
automatic operation.
Automatic
Controller
+
-
7 (+ input)
1 (- input) or 4 (- input)
TB1
Figure 3-1. Automatic Controller Input Connections
3.4. Remote Manual Control (Only) with a Potentiometer
This potentiometer may be located on a remote panel near other controls related to the process being
powered by the 3PCI. It may be calibrated to correspond to a percentage of rated power output, process
temperature, or some other parameter. The potentiometer may be 500
Ω
to 5 k
Ω
, and should be rated at 0.5
watt, minimum.
1. With the power to the 3PCI turned off, connect the potentiometer as shown in Figure 3-2. The CW
position is the full power output position. Terminal
TB1-8
is internally connected to a positive DC voltage
source.
2. Connect an analog voltmeter across terminals
X1
,
X2
, or
X3
. Set the voltmeter range to measure the full
output voltage.
3. Set the remote potentiometer fully CCW.
4. Close the fused disconnect or circuit breaker to apply power to the 3PCI. The unit should be energized,
with no output.
5. Adjust the bias control for zero output voltage.
6. Adjust the manual pot fully CW. Adjust the gain control for maximum output voltage.
8 (+10 Vdc)
2 (+ Input)
4 (Common) or 1 (Common)
TB1
Manual
Pot
(5 k
Ω
)
CW
Figure 3-2. Remote Control with a Potentiometer
Caution - Electrical Hazard! Hazardous voltages exist at the exposed 3PCI heat sinks and at
the load unless the line-source fused disconnect or circuit breaker is open or off. This is true even
when the SCRs are turned off. Always remove power to the unit before attempting service.