BRUEL & KJAER System V - Cleanliness of Exciter Body; Field Coil Cleaning; Care of Exciter Head; Removal of Cable

8.2.2. Cleanliness of Exciter Body
The air inlet screen at the bottom of the Exciter Body sho ul d be inspected daily and
cleaned when necessary. It is possible for loose pieces of paper and other light debris to
be
drawn up against the air inlet screen. A periodic inspection schedule is recommen ded.
The top of the Exciter Body should be inspected prior to mounting an Exciter Head, or if
one Exciter Head is being used continuously, the head should be removed periodically for
inspection . The upper surface of the Field Coil is visible through the openings in the iron .
If
the surface is dirty , and particularly if any of the air passages look blocked or ob-
structed, the field coils should be va c uumed clean . If vacuuming does not open the pas-
sages, see
section 8 . 2.3.
Dirt, especially sand or other gritty dirt, should be kept out of the Rotation Bearing / Brake
assembly . If the exciter has been exposed to such dirt, the dirt in this area should be
blown out with a jet of air , or if severe, washed out with a mild solvent , befor e the Exci-
ter Body is rotated.
8.2.3. Field Coil Cleaning
The field coils each have many annular passages for cooling air . These passages should
be kept clean .
The high velocity air flowing through the field cooling passages normally prevents a seri-
ous accumulation of dirt in these passages. However , the user is advised to inspect the
upper surface of the Upper Field Coil at regular intervals. Since the air flows downward
through the passages, the worst accumulation of dirt is at the top . The upper surface of
the Upper Field Coil is exposed when the Exciter Head is removed .
If it
should be necessary to clean the field coils, a strong vacuum cleaner will remove
most dirt from the top. For guidance on dealing with more persistent dirt, consult your
B & K representative .
8.3. C ARE OF EXCITER HEAD
A B & K Exciter Head will provide long service if it is not abused. Although most care is
just "Common Sense" careful treatment, a few suggestions may be useful.
8. 3 .1. Removal of Cable
Before an Exciter Head is removed from the Exciter Body, the cable from the Power Am-
plifier should be disconnected from the Head. This serves two purposes : (1) It prevents
i nadvertent application of power to the Exciter Head while it on is the workbench without
cooling , thus burning out the Driver Coil, and (2) If the cable from the Power Amplifier
were still connected to the Exciter Head, it would be hanging over the side of the work-
bench . It would be easy to step on such a cable and pull the head off the table onto the
floor , possibly causing severe damage .
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