User and Programming Manual - Rev H
California Instruments
P Series
May 2000
29
6.3 Non-Routine Calibration
6.3.1 Current limit Calibration
1. Connect the test equipment to the power source as shown in Figure 6-2.
2. Locate R31 on the A4 assembly board. Turn R31 clockwise several turns.
3. Connect the load to the output. Use the 100 milliohm current shunt in series with the load
to measure the AC load current. Refer to Table 2 for the proper full load.
4. Set the Current limit with the right shuttle to 95% of the current measured with the shunt
and AC multimeter.
5. Turn R31 counterclockwise slowly until the output faults.
6.3.2 Voltage Measurement Calibration
1. This calibration requires the use of 801P/1001P/1251P GUI and a PC communicating with
the AC source via the RS232 interface.
2. Refer to 801P/1001P/1251P software documentation for Installing and starting the GUI to
monitor the voltage measurements
3. Program the output voltage to 170 volts and 200 Hz. The output must not be loaded.
4. Monitor the output voltage with an external voltmeter.
5. Locate R128 on the A3 assembly board. Adjust R128 so that the measured value reported
by the GUI measurements agrees with the external voltmeter.
6.3.3 DC Offset Adjustments
1. Program the output voltage to 230 volts and 60 Hz.
2. Measure the DC offset at the output using Fluke 8840 or equivalent. Verify that offset is
less than
±
.025V. Measure the DC voltage access a 22
µ
f capacitor connected to the
output through a 215K resistor. Refer to Figure 6-2.
3. Locate R46 on the A3 assembly board. Adjust R46 if required to maintain the DC offset
within
±
.0.025V.