Lakeshore Learning Materials 622 - Manual (Page 65)

Lake Shore Model 620/622/623/647 Magnet Power Supply User’s Manual
Error Messages & Troubleshooting 5-7
Output Voltage Verification
5. From the MPS front panel, select the Instrument Setup (INSTR. SETUP) menu and change compliance
voltage to 5 V. Press the Normal Display key to return to the Normal Display screen.
6. Set output current to +1 A. Use the DVM to read the voltage across the MPS unit(s) output terminals. The
reading should be +5 V ±0.3 V.
7. Set output current to 1 A. The DVM should read 5 V ±0.3 V.
8. Turn OFF MPS.
Output Current Verification
9. Use AWG #4 wire to connect the current monitor shunt between the MPS +OUT and -OUT terminals.
Connect DVM across the shunt monitoring terminals. Note DVM offset reading.
10. Turn ON MPS. Within two seconds, the Normal Display appears.
11. Select the Instrument Setup (INSTR. SETUP) menu and change compliance voltage to 2 Volts. Press the
Normal Display key to return to the Normal Display screen.
12. Wait 1 minute for MPS output to settle. The DVM should read the same as recorded for Step 9 ±0.01 mV.
13. Set output current to +50 Amps The DVM should read about +33 mV. After about 1 minute, the DVM
should read +33.333 mV ±0.117 mV (not including offset from Step 9).
14. Models 622/623 ONLY: Set output current to +100 Amps. The DVM should read about +66 mV. After
about 1 minute, the DVM should read +66.666 mV ±0.233 mV (not including offset from Step 9).
15. Set output current to -50 Amps. The DVM should read about -33 mV. After about 1 minute, the DVM
should read -33.333 mV ±0.117 mV (not including the offset from Step 9).
16. Models 622/623 ONLY: Set output current to -100 Amps. The DVM should read about -66 mV. After
about 1 minute, the DVM should read -66.666 mV ±0.233 mV (not including the offset from Step 9).
17. Set output current to 0 A.
Fault/RI Operation Verification
18. Short the MPS RI input with a shorting jumper. MPS output current should drop to 0 A, and the alarm
should sound about once per second. Verify the MPS displays the RI screen shown in Paragraph 3.7.1.
19. With the unit ON, disconnect AC power connector. The front panel circuit breaker should trip.
20. The performance verification is complete.