Ametek 1251RP Series, User And Programming Manual

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RP Series March 2011
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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 P/RP GUI and a PC communicating with the AC
source via the RS232 interface. The IEEE interface can be used as well, but requires
that the PC is equipped with a National Instrument GPIB controller card.
2. Refer to Section 9 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 a Fluke 8840 or equivalent. Verify that offset
is less than 0.025V. Measure the DC voltage across a 22 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 0.025 VDC.