AMETEK MX Series Rev: AY - Manual (Page 174)

User Manual - Rev AV AMETEK Programmable Power
MX Series 174
6.4.6 Three Phase Mode
As indicated earlier, for 3-Phase power system, repeat the preceding steps for the Phase B and
C outputs. The order in which the outputs for each phase are calibrated is not important.
Press the PHASE key to select each output to be calibrated. Monitor the output of the respective
phase by moving the HI input of the Digital Multimeter. The LO input should remain connected to
the common LO of the sense connector.
For the MX45-3Pi operating in single-phase mode, the output voltage calibration does not have
be repeated in single phase mode as the same coefficients for phase A are used in either phase
mode.
6.4.7 Phase Angle Calibration
Output phase angle calibration is required only on MX Series models capable of three-phase
mode operation. A phase meter is required to perform this calibration.
This calibration can be done in either high or low voltage range as long as the maximum input
voltage of the phase meter input is not exceeded. Select AC mode, thee-phase mode, 120Vac.
60 Hz. Program all three-phase outputs to the same voltage.
For best results, the output of all amplifiers should be loaded to at least 80% of full scale voltage
current on all phases at the same time. This requires a three-phase load. If no such load is
available, perform this calibration with no load.
Proceed as follows:
1. Program AC mode, 3 phase, low voltage range, 120Vac, 50 or 60 Hz. Close output relay.
2. Select the OUTPUT CAL screen.
3. Connect phase meter between phase A and B outputs.
4. Use the PHASE key to select phase B in the upper right corner of the CAL screen.
5. Close output relay and measure the phase angle between phase A and Phase B.
6. Adjust PHASE OFST cal coefficient up or down and press ENTER key until phase B
offset is 240° ± 0.5° or better.
7. Connect phase meter between phase A and C outputs.
8. Use PHASE key to select phase C in the upper right corner of the CAL screen.
9. Adjust PHASE OFST cal coefficient up or down and press ENTER key until phase C
offset is 120° ± 0.5° or better.