The High Voltage Power Supply (MMPS - MINIMILL Power Supply) is the source of power for the servo amplifiers.

It operates with 3 phase 208Vac or 240Vac single phase power. It rectifies the incoming AC power and supplies 320-340Vdc to the servo amplifiers.

The High Voltage Power Supply also contains the regeneration circuit used for dynamic braking.

1. 69-2000E  320V Power Supply (Terminal Strip) CHC 
2. 32-5557 320V Power Supply (Molex Connectors) CHC / NGC
3. 32-5566 320V Power Supply ( Terminal Strip) CHC / NGC
4. 32-5566A 320V Power Supply (Terminal Strip with Fuse) CHC / NGC
   Important: Do not discharge the 32-5566A MMPS using a resistor, this will cause the fuse to blow.  Instead wait until the HV led light has turned off.

Corrective Action:

Diagnostic DC Voltage Check

1. Press the [POWER ON] button.
2. Measure the DC voltage between pins 1 and 2 of connector J4 on the MMPS.
3. Compare the measured voltage with the DC VOLTAGE on the diagnostics page on the control. The readings must match +-2%.
4. Press the [POWER OFF] button.
5. Disconnect the DC Bus cables from connector J3 on the MMPS.
6. Press the [POWER ON] button.
7. Monitor the DC VOLTAGE on the diagnostics page of the control. If the readings do not match, the problem can be:
   • A bad connection on the cable that carries the voltage monitor signal to the controller PCBs. Make sure there is a tight connection on the J6 connector on the MMPS and the P17 connector on the CHC Maincon/Mocon.
   • A faulty MMPS if you have incorrect voltage at P17 on the Maincon/Mocon.
   • A faulty Maincon/Mocon PCB if you have the correct voltage on the cable at the P17 connector of the Maincon/Mocon. There is 0.01 VDC for every 1 VDC Bus. For example, 320 VDC must show 3.2VDC.

Low DC Buss caused by shorted Amplifiers Check

1. Press the [POWER OFF] button.
2. Disconnect the DC Bus cables from connector J3 on the MMPS.
3. Press the [POWER ON] button.
4. Monitor the DC VOLTAGE on the diagnostics page of the control.
   • If the DC Bus goes back to the nominal value, there is a short in one of the servo amplifiers. A low resistance or a short is a sign of a faulty servo amplifier.
   • If the readings match and the alarm continues, then the problem is a faulty MMPS.

Corrective Action:

Inspect the MMPS. Disconnect all cables from the MMPS.

Bridge rectifier to chassis check.

1. Set your meter to resistance mode (Ohms).
2. Check terminals 1, 2, and 3 to chassis ground. If the reading does not show an open circuit (O.L) the MMPS is damaged.

Bridge rectifier to DC bus terminal check

1. Set the meter in diode test mode.
2. Put the black lead on J3 pin 2. With the red lead, check terminals 1, 2, and 3 of J1.
3. Wait until the reading on your meter settles. If the meter does not show show an open circuit (O.L) the MMPS is damaged.
4. Put the black lead on J3 pin 1. With the red lead, check terminals 1, 2 & 3 of J1.
5. Wait until the reading on your meter settles. If the meter does not show show an open circuit (O.L) the MMPS is damaged.

Corrective Action:

REGEN Load Check:

1. Set the meter to resistance mode (Ohms).
2. Disconnect the REGEN load from the MMPS from connector J5.
3. Measure the resistance across the leads. The reading must be between 9.5 and 12.5 ohms. If the REGEN load is within specification, there can be a problem with the MMPS.
4. Measure the resistance across pins 1 on J3 and pin 3 of J5 of the MMPS. A short is a sign of a faulty MMPS.