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both ends by sealed ball bearings no lubrication of
the generator is required.
Inspection - The cover band should be removed
and the commutator and brushes inspected at reg-
ular intervals.
If
the commutator is dirty, it may be
cleaned with No. 00 sandpaper.
Blowout dust.
NEVER USE EMERY CLOTH TO
CLEAN COM-
MUTATOR.
If
the commutator is rough, out of round, or has
high mica, it should
be
turned down in a lathe and the
mica undercut. Worn brushes should be replaced.
They can be seated with a brush seating stone. The
brush seating stone -is an abrasive material which,
held against the revolving commutator, car r i e s
under and seats the brushes in a few seconds. Blow
out dust. NEVER USE EMERY CLOTH. Check brush
spring tension, which should be approximately 25
ounces.
Generator Disassembly.
At regular intervals, the actual mileage or time
depending on the type of operation, the generator
should be disassembled for a thorough cleaning and
inspection of all parts. Never clean the armature or
fields in any de greasing tank, or with grease dis-
solving materials, since these may damage the in-
sulation. The ball-bearings should never be washed
in gasoline or any other solvent since this would
dissolve the grease in them and ruin the bearings.
The commutator should be trued in a lathe and the
mica undercut
if
necessary.
All wiring and con-
nections should
be
checked. Rosin flux should be
used in making all soldered connections. Acid flux
must never be used on electrical connections.
(2) Checking Inoperative Generator.
Several conditions may require removal of the
generator from the engine and further checking of the
generator as follows:
1. No output
2. Unsteady or low output
3. Excessive output
4. Noisy generator
1. No Output
Remove cover band and check for sticking or worn
brushes and burned commutator bars. Burned bars,
with other bars fairly clean, indicate open circuited
coils.
If
brushes are making good contact with com-
mutator and commutator looks okay, use test leads
and light and check as follows:
a. Raise grounded brush, check with test pOints
points from "A" terminal to frame. Light
should not light.
If
it does, the generator is
grounded; raise other brush from com-
mutator
and check field, commutator and
brush holder to locate ground.
b.
If
the generator is not grounded, check field
for open circuit.
c.
If
this field is not open, check for shorted
field. Field draw at 12 volts should be 1.62
to 1.69 amperes. Excessive current draw
indicates shorted field.
d.
If
trouble has not yet been located, remove
armature and check on growler for short
circuit.
2. Unsteady' or Low Output
Check as follows:
a. Check brush spring tension and brushes for
sticking.
b. Inspect commutator for roughness, grease
and dirt, dirt in slots, high mica, out of
round, burned bars.
With any of these
conditions, the commutator must be turned
down in a lathe and the mica undercut. In
addition, with burned bars which indicate
open circuit, the open circuit condition must
be eliminated or the armature replaced.
3. Excessive Outp'ut
Excessive output usually results from a grounded
generator field - grounded either internally, or in the
regulator.
Opening the field circuit (disconnecting
lead from "F" terminal of regulator or generator)
with the generator operating at a medium speed will
determine which unit is at fault.
If
the output drops
off, the regulator is causing the condition.
If
the
output remains high, the field is grounded in the
generator, either at the pole shoes, leads, or at the
"F" terminal.
4. Noisy. Generator
Noisy generator may be caused by loose mounting
or drive pulley, or worn, dry or dirty bearings, or
improperly seated brushes. Brushes may
be
seated
by using brush seating stone, referred to above.
Installation Caution
After the generator is reinstalled on the engine,
or at any time after leads have been disconnected
and then reconnected to the generator, a jumper lead
should be connected MOMENTARILY between the
BATTERY and GENERATOR terminals of the reg-
ulator, before starting the engine. This allows a
momentary surge of current from the battery to the
generator which correctly polarizes the generator
with respect to the battery it is to charge. Failure to
do this will result in vibrating and arcing relay cutout
pOints which will soon be ruined so that regulator re-
placement will be required. In addition, the battery
will not charge so
it
may run down.
Section 19
DELCO-REMY GENERATOR REGULATOR
SERVICE INSTRUCTIONS
General
Delco-Remy Voltage Regulators for aircraft in-
stallation combine three units, a cutout relay, a
current regulator and a voltage regulator, mounted
on the same base and enclosed by a single cover.
These three units provide complete control of
ilie
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