American Magnetics 03300PS-430-601 High Stability Integrated Power Supply System - Manual (Page 164)

146 Rev. 5
Service
Troubleshooting Hints
STATION CONNECTORS and the connectors on the magnet
support stand top plate. Refer to Table A-1 on page 151.
5.2.13 The system current ramps slowly from zero
With the Model 601 Energy Absorber in the system, an initial charging
delay will be observed when operating without an inductive load (e.g. a
persistent switch is not heated on a connected magnet).
1. To decrease the amount of time delay, increase the ramp rate to 1
A/sec or greater value. Remember to decrease the ramp rate, if
necessary, before heating the persistent switch of the connected
magnet and attempting to ramp the current.
2. The charging delay will not be observed when operating with an
inductive load.
5.2.14 The Model 601 FAULT LED energized with audible alarm
1. Verify that the supplied external DC power converter is connected
to the rear of the Model 601, and the AC power cord is also
connected to the appropriate power receptacle.
2. If the DC power converter is connected properly, observe if an
internal green LED is energized by looking through the Model 601
rear-panel grating. If the green LED is energized, then the DC
power converter is operating correctly.
If the internal green LED is not energized, then the DC power
converter has failed, or AC power to the DC power converter has
been lost. Contact an Authorized AMI Technical Support
Representative for a replacement.
3. If the DC power converter is connected and the internal green LED
is energized, then the FAULT LED indicates the failure of an
internal energy absorbing element. Do not continue to operate the
unit and contact an Authorized AMI Technical Support
Representative for further instructions.
5.2.15 There is excessive LHe boil-off during operation.
Excessive LHe consumption is usually attributable to one or both of the
following: thermal energy being conducted into the cryostat or electrical
energy being converted into thermal energy within the cryostat. Analyzing
the circumstances under which the high boil-off occurs will help determine
what is causing the problem.
1. For magnets equipped with switches for persistent operation, verify
that the persistent switch heater power supply is operating at the