AMI 420, Installation, Operation And Maintenance Instructions, Page: 64 / 134

46
Rev. 7
Operation
Setup Menu : Load
3.2.2.4 Persistent Switch Installed
Indicates whether a persistent switch is installed. Use the
237,21
key to cycle between YES and NO. If YES is selected, the persistent
switch current and heating time for the switch must be specified.
The default value is YES unless preset by AMI.
3.2.2.5 Persistent Switch Current
The persistent switch current can be set from between 0.1 to 100.0
mA. The default value is 10.0 mA unless preset by AMI.
3.2.2.6 Persistent Switch Heated Time
The persistent switch heated time is the amount of time required
for the persistent switch to completely heat and become resistive.
The time may be set from 5 to 120 seconds. The default is 15
seconds unless preset by AMI.
During the persistent switch heating period, the Model 420
ramping functions are disabled. The time delay is necessary to
ensure that the Model 420 will not switch to a higher gain required
for proper magnet operation before the magnet is actually available
in the circuit. If magnet operation is not stable after expiration of
the heating period, increase the heating period to allow more time
for the switch to heat. The default of 15 seconds is adequate for the
majority of persistent switches.
3.2.2.7 Enable Quench Detect
The automatic quench detection function of the Model 420 may be
enabled or disabled according to the preference of the operator. Use
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