8 cannot charge the magnet to desired field, 10 cannot place the magnet in persistent mode, Service – American Magnetics 4Q12125PS-430 Integrated Power Supply System User Manual

Page 157

Rev. 5

139

Service

Troubleshooting Hints

2. Verify the power supply is configured for remote programming,

voltage-to-voltage mode.

5.2.6 Cannot charge the magnet at the selected ramp rate.

1. Ensure the Model 430 Programmer is properly configured for the

2. Ensure that the persistent switch heater is on and the switch

heated time has expired. Ramping is disabled during the switch

heating period.

4. Check for excessive wiring resistances in the magnet-power supply

loop which may prevent proper charge/discharge voltages at the

magnet. Use the local voltmeter on the power supply to see if the

proper voltages exist across the various components in the magnet

power loop. Loose or oxidized interconnections often exhibit

excessive resistances.

5.2.7 Cannot discharge the magnet at the selected ramp rate

1. Ensure that the persistent switch heater is on and the switch

heated time has expired. Ramping is disabled during the switch

heating period.

5.2.8 Cannot charge the magnet to desired field.

3. Ensure that the Model 430 Programmer supply setup submenu is

configured to match the connected power supply, e.g. check that the

Model 430 Programmer is configured for the proper voltage-to-

5.2.9 Current in only one direction from 4-quadrant supply

1. Ensure the Model 430 Programmer is configured to allow negative

power supply voltage according to section 3.10.1.1.1.1 and negative

power supply currents according to section 3.10.1.1.1.3.

2. Verify that the Model 430 Programmer is configured for the proper

voltage-to-voltage programming range according to section

5.2.10 Cannot place the magnet in persistent mode.

Ensure there is adequate LHe level in the cryostat to allow the

persistent switch to cool to the superconducting state.