Installation, Operation and Service Manual
LKP Series
© 2016 DynAmp, LLC
Page 20
041738 I
Study the initial voltage readings. First, if none of the readings are below 3V or above
30V, the head position may be left as is. If some of the voltages are in the 31-40V range,
a change should be considered. In some cases, a channel fuse might blow if the channel
voltage is above 35 volts. 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. If any
readings are over 40V, the head must be moved.
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 has higher-than-
average readings, whereas the section directly 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 6 = 12 V
Chan 3 = 36 V and Chan 8 = 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 3 and 8 voltages, and moved
horizontally (bringing channel 6 nearer the bus) to balance the channels 1 and 6 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.
CAUTION
Unless instructed otherwise by the factory, if the head position must be changed it
is important that it should be kept in a vertical plane if possible. The head can be
mounted in a tilted plane without loss of accuracy. However, such mounting can
impose stresses at the center joining points especially if one half is supported
solely from the other half.
If it is necessary to tilt the head out of the vertical plane to achieve lower channel voltages,
first make sure each half is independently supported at four points, and then carefully
loosen the joining bolts. Independently move each half into the new position, visually
align. Firm up the support system and re-bolt. A gap of at least ¼in. (7 mm) must be
maintained between any part of the head and bus to prevent possible buildup of a
conductive dust path between them.
Using the initially recorded channel data, move the head position as necessary or
desirable, observing the above precautions. Make spot readings of the channels in
question to confirm results. When the spot readings are satisfactory, record their values
and measure and record the values of all other channels in table 5.2. (Additional copies
may be made to use for spot readings or trial runs.) Check the diagram to see if the
position is now satisfactory. Once balance is apparently achieved, it is advisable to let the
system operate 24 hours to thermally stabilize the head. Then make any necessary
adjustments and record the final position values on one of the book copies of table 5.2 and
label accordingly. This data will be valuable for future troubleshooting or maintenance.
