User guide

Rev. 5 35
Operation
Shift Key Commands : Ramp Rate
Pressing the right arrow key accesses the next (third) segment
ramp rate display. The segment 3 ramp rate is set to a value of
0.05.
Pressing the right arrow key accesses the segment 3 current range
display.
Note
Note that when there is more than one segment, the upper bound of
the last segment is always the Magnet Current Rating
1
(or the
Current Limit if set lower than the Magnet Current Rating); it will
be displayed as “±Limit” and cannot be edited.
Now, when current is in the range of 0 to ±55 A, ramping will be
controlled at ±0.2 A/s. When current is in the range of ±55 to ±58 A,
ramping will be controlled at ±0.1 A/s and when current is greater
than ±58 A (up to the limit of 60 A), ramping will be controlled at
±0.05 A/s.
If ramp rate of a ramp segment is being edited while the Model 430
is ramping and the system current/field transitions from the
currently edited segment to the next before the adjustment has
been committed with the
ENTER key, the adjusted value will be
discarded. The display will update to show the new segment ramp
rate, and the fine adjust knob will apply to the new segment
(assuming the
ENTER key is pressed before the segment has
completed).
If at some later time it is desired to temporarily set the Current
Limit to a new value lower than the Magnet Current Rating, for
example 56 A, this lower value will override the Magnet Current
Rating. Now only the first two ramp segments would be active since
1. Refer to section 3.10.2.4 on page 52 and section 3.10.2.3 on page 51.
+50.00 A - Seg.3 Ramp Rate (A/sec)
+0.50 Vs ±0.0500
+50.00 A - Seg.3 Range (A)
+0.50 Vs ±58.0 to ±Limit