DELCOTRON 6Y-3
OHMMETER
C H E C K I N G F O R
G R O U N D E D C IR C U I T
C H E C K I N G F O R
O P E N C IR C U IT
Fig. 4C--Checking Rotor
Grounds
Connect test lamp or ohmmeter from either slip ring to
the rotor shaft or to the rotor poles. If the lamp lights or if
the ohmmeter reading is low, the field windings are
grounded.
Opens
Connect one test lamp or ohmmeter lead to each slip ring.
If the lamp fails to light or if the ohmmeter reading is high,
the windings are open.
Short Circuit
The windings are checked for shorts by connecting a 12
volt battery and an ammeter in series with the two slip rings.
Note the ammeter reading. An ammeter reading above the
specified field amperage draw indicates shorted windings.
Refer to Specifications at the end of this manual.
T EST IN G ST A TO R (Fig. 5C)
Grounds
Connect a 110-volt test lamp or an ohmmeter from any
stator lead to the stator frame. If test lamp lights or if ohmm
eter reads low, the windings are grounded.
Open Circuit
If lamp fails to light or if ohmmeter reads high when
successively connected between each pair of stator leads, the
windings are open.
Short Circuit
A short in the stator windings is difficult to locate without
special test equipment due to the low resistance of the wind
ings. However, if all other electrical checks are normal and
the generator fails to supply rated output, shorted stator
windings are indicated. Also, look for heat discoloration on
the windings.
TESTIN G D IO D E S (Fig. 6C)
Two methods may be used to check diodes for shorts or
opens, a test lamp of not more than
1 2
volts or an ohmmeter.
CAUTION: Do not use a 110-volt test lamp to test
diodes.
Test Lamp Method
Diode in H eat S in k
With the stator previously disconnected connect one of
the lamp leads to the heat sink and other lead to the diode
lead. Observe condition of lamp. Reverse the lamp leads and
observe condition of lamp. A good diode will allow the lamp
to light in only one of the test directions. If lamp lights in
both directions or fails to light at all, the diode is defective.
OHMMETER
Fig. 5C -C he cking S tator fo r Grounds or Opens
OHMMETER
OHMMETER
CHEVROLET OVERHAUL M A N U A L SUPPLEMENT
Summary of Contents for 40 60 Series
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