American Magnetics 430, Installation, Operation And Maintenance Instructions

Page: 130 / 254

114 R
EV
9
A
MERICAN
M
AGNETICS
, I
NC
. O
PERATION
: P
ERSISTENT
S
WITCH
C
ONTROL
1. Turn on the persistent switch heater by pressing the
PERSIST. SWITCH
CONTROL
key to heat the persistent switch heater.
NOTE
If the PSwitch Transition setting
48
is set to Timer, the number in
parentheses in the display indicates the number of seconds
remaining in the timer countdown. If the PSwitch Transition
setting is set to Magnet Voltage, the number in parentheses is the
running magnet voltage variance. For the magnet voltage-based
switch transition, a variance value of zero indicates the switch is
in the cooled state.
2. After the persistent switch heater has been heated for the preset heating
time specified by the PSwitch Heated Time setting, or a transition is detected
by the magnet voltage-based option, the display will show the default display
and wait at zero current for a command from the operator. The magnet is no
longer isolated from the power supply output.
P
ROCEDURE FOR
E
NTERING
P
ERSISTENT
M
ODE
In order to enter the persistent mode of magnet operation, the user
should perform the following steps:
1. Use either automatic or manual ramping to achieve the desired field or cur-
rent in the magnet.
2. The Model 430 Programmer must be in either the HOLDING or PAUSED
mode at the target field or current.
3. The Model 430 Programmer must be at the default field/current display.
49
4. Press the
PERSIST. SWITCH CONTROL
key to turn off the persistent
switch heater and automatically ramp the power supply to zero current:
a. After the
PERSIST. SWITCH CONTROL
key is pressed, the
Model 430 Programmer requests that the
ENTER
key be pressed as
48. Refer to page 85.
0.00 A Mode: Heating Switch (4)
0.00 Vs PSwitch Heater: ON
0.00 A
P
Mode: Paused
0.00 Vs PSwitch Heater: ON
49. Refer to page 51.