10. PREOPERATIONAL CHECKS.
a. Before the start of any generator, alternator, or starter test, the
controls of the test stand must be set to specific positions. This action prevents
damage to the test stand circuitry. It also prevents damage to the unit under
test. Each test procedure must begin with the controls positioned as indicated in
figure 15. Fill in the figure and key number information by reviewing figures 1
through 11.
b. Each of the seven meters must be checked for static charges and adjusted
for a proper zero. The zeros are adjusted with the adjustment screws located in
the lower center of the meter lens. Static charges can be built up on the lens of
the meters. Accuracy is affected if a static charge exists. To check for the
presence of a static charge, move a hand rapidly across the front of the meter.
The hand should be as close to the lens as possible but should not touch it. If a
charge is present, the meter pointer will follow the hand for a short distance. If
this occurs, the lens must be cleaned and recoated with antistatic and cleaning
compound.
c. The battery condition must be checked each time the test stand is placed
in operation. In nearly all cases, early battery failure can be traced to a lack
of preventive maintenance. When the batteries are used during tests they are
subjected to heavy current loads. Improper care will cause them to deteriorate
rapidly.
d. The battery condition is checked after the control position and meter
condition have been checked. Proceed as follows:
(1) Place the battery charge switch ON.
(2) Note the DC voltmeter range selector is set at 50V.
(3) Turn DC voltmeter circuit selector to BAT.
(4) Rotate battery selector to 6V (DC voltmeter should read 6+ volts).
(5) Rotate battery selector to 12V (DC voltmeter should read 12+ volts).
(6) Rotate battery selection to 24V (DC voltmeter should read 24+
volts).
(7) Return battery selector to OFF.
(8) Return DC voltmeter circuit selector to RECT/GEN.
(9) Return battery charge switch to OFF.
Note. - If voltage readings are not adequate, the batteries must be charged.
Additional information on the lead-acid battery is presented later in this
lesson.
e. The varidrive assembly should be checked under no-load conditions each
time the test stand is operated. Proceed as follows:
(1) Place the circuit breaker switch to ON.
OS 010, 3-P19
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