Testing Shunt Field Coil Standard And Radio Three Brush Generator

from .6 to 1.0 ampere; Radio Generator, .8 to 1.2 amperes. If ammeter shows no reading, coil is open (see that terminal connections are tight and field coil wires are not broken at terminals). If reading is appreciably higher than—Standard Generator 1.0 ampere; Radio Generator 1.2 amperes, coil is shorted internally or grounded, or "switch" terminal is grounded.

Model 32E2 and 32E2R-Radio Two Brush Generator

Field coil wires disconnected when positive (upper) brush is removed, must remain disconnected and terminals must not touch any part of generator frame when making tests. Do not disconnect field coil wires from field coil wire terminal (connected with "switch" terminal) unless necessary.

Testing Regulating Field Coil (see Illus. 85):

1. Touch test point "F" to "switch" terminal of generator and test point "G" to disconnected regulating field coil wire terminal. The ammeter should read between 1.9 to 2.3 amperes. If ammeter shows no reading, field coil is open (see that terminal connections are tight and field coil wires are not broken at terminals). If reading is appreciably higher than 2.3 amperes, field coil is shorted internally.

2. With test point "F" still on switch terminal, ground other test point by moving it to generator frame, as indicated by dotted lines "I". Ammeter should show no reading on this test. If ammeter registers a reading, either or both field coils, or "switch" terminal is grounded.

3. If test shows ground, disconnect field coil wires from field coil terminal. If ground is eliminated, one or both field coils are grounded. If ground still exists, "switch" terminal is grounded.

Testing Shunt Field Coil (see Illus. 85):

4. If testing regulating field coil did not necessitate disconnecting field coil wires from field coil terminal because of a ground, touch test point "F" to "switch" terminal and other test point to disconnected shunt field coil wire as indicated by dotted lines "H". The ammeter should read .8 to 1.2 amperes. If ammeter shows no reading field coil is open (see that terminal connections are tight and field coil wires are not broken at terminals). If reading is appreciably higher than 1.2 amperes coil is shorted internally.

5. If test showed that a field coil is grounded, the defective coil can be identifed by ammeter registering a reading when touching test point "F" to one field coil wire terminal and other test point to generator frame. Check each field coil separately.

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