Installation, Operation and Service Manual
LKP Series
© 2016 DynAmp, LLC
Page 21
041749 K
CAUTION
Avoid operating the unit for an extended time with any channel output that exceeds the
maximum shown values. This will permanently damage the system. For voltages over
what is shown in Table 5.2, consult the factory.
5.10 MAGNETIC CENTERING
The distribution of load, or heat, among all channels will be optimized by magnetic
centering of the head relative to both the bus and the total magnetic environment of the
head. In general, this simply means moving the head so that channels with high voltage
readings will be farther from the bus, and channels with low readings will be nearer the bus.
Whether or not the head should actually be moved depends on three factors:
A.)
The possible impracticality or difficulty of moving the head because of
support-system requirements, clearances available, etc.
B.)
The necessity of moving the head because of voltage readings that are too high or
too low for certain channels.
C.)
The desirability of moving the head to obtain a better balance of channel voltages.
Study the initial voltage readings. First, if none of the readings are below 3 V or above the
maximum balanced channel voltage, the head position may be left as is. If some of the
voltages are near the maximum 130% unbalance voltage range, a change should be
considered (lower channel voltages may not be achievable on the larger systems running
at full capacity). In some cases, a channel fuse might blow if the channel voltage is above
the maximum unbalanced voltage. In those cases, the head will have to be moved, or, if
the head can’t be moved, then a higher rated fuse can be installed. Using higher rated
channel fuses shall be evaluated and approved by the factory only on a case-by-case
basis.
As the voltage readings are compared from channel-to-channel around the head, a pattern
may be observed which indicates that a section of adjacent channels have
higher-than-average readings, whereas the opposing section across the bus has lower
readings. Looking for patterns of this type will help in deciding how the head should be
moved to obtain a better balance of channel voltages.
As a simplified example of optimizing the head position, assume these readings are
obtained for two pairs of directly opposite channels:
Chan 1 = 25 V and Chan 9 = 12 V
Chan 5 = 36 V and Chan 13 = 12 V
Note that it is not sufficient to consider just a few channels; all channel readings must be
considered for repositioning. However, for this simplified example the head would be
raised (relative to the bus) to balance the channels 5 and 13 voltages, and moved
horizontally (bringing channel 9 nearer the bus) to balance the channels 1 and 9 voltages.
Note that (1) it would not be necessary to change the horizontal positioning since the
channel 1 voltage is not excessive and (2) an absolute balance between opposing
channels is unnecessary. Lowering the higher readings is more important than achieving
perfect balance.
