6-, 12, and 24-volt combination.
b. The load and starter DC ammeter (fig 5), in conjunction with its five
position selector switch, is able to monitor DC currents up to 1,000A. Ranges of
0-50A, 0-150A, 0-200A, 0-500A, and 0-1,000A can be set up using the range selector
in conjunction with the two scales on the meter face. Operators must be trained to
read the correct scale and to select the range which will give the best resolution.
When making tests the meter range should be selected so that the meter indication
is well up scale. Trying to measure 40 amperes on the 0-1,000A range would be
incorrect unless there is an overriding safety factor. Normally, 40 amperes should
be read on the 0-50A scale. This monitoring system is used to perform measurements
when the test stand circuits are connected to make various tests on starters
field current accurately. Located next to the load and starter DC ammeter is the
monitoring system used to make these measurements (fig 5). The field and battery
charger DC ammeter is a two-scale meter. Zero on both scales is located in the
center and the meter may deflect in either direction from that point. Deflection
right or left of center depends upon how the monitoring system is connected in the
overall test circuit. The two scales are 5-0-5 and 15-0-15. The field and battery
selector switch is a five-position switch. There is an OFF position and three
field current measuring positions which set up the meter to read 5, 15, or 30
amperes at full scale. The fifth position, "battery charging," sets the monitoring
system to measure 30A full scale.
OS 010, 3-P4