Test Between Windings; Rotor Insulation Resistance Test; Cleaning The Generator; Drying The Generator - Generac Power Systems GP Series Diagnostic And Repair Manual

OLDER
77A
66A
2
6 5
7 8
55
6
Figure 4-65. C1 Connector Pin Location Numbers
(Female Side)

Test Between Windings

Insert a paper clip into pin Location 3 (wire 55A).
1.
Connect the red tester probe to the paper clip.
Connect the black tester probe to stator lead 11.
Refer to steps 5a through 5c of
Windings To Ground.
Repeat step 1 at pin Location 6 (wire 2) and stator
2.
Lead 11.
Repeat step 1 at pin Location 8 (wire 55) and stator
3.
lead 11.
For the following steps (4 through 6) an additional paper
clip (or similar item) will be needed:
Insert a paper clip into pin Location 3 (wire 55A).
4.
Connect the red tester probe to the paper clip.
Insert additional paper clip into pin Location 6 (wire
2). Connect the black tester probe to this paper
clip. Refer to steps 5a through 5c of
Stator Windings To
Insert a paper clip into pin Location 3 (wire 55A).
5.
Connect the red tester probe to the paper clip.
Insert additional paper clip into pin Location 8 (wire
55). Connect the black tester probe to this paper
clip. Refer to steps 5a through 5c of
Stator Windings To
Insert a paper clip into pin Location 6 (wire 2).
6.
Connect the red tester probe to the paper clip.
Insert the additional paper clip into pin Location 8
(wire 55). Connect the black tester probe to this
paper clip. Refer to steps 5a through 5c of
All Stator Windings To

Rotor Insulation Resistance Test

Before attempting to test rotor insulation, the brush holder
must be completely removed. The rotor must be
completely isolated from other components before starting
the test. Attach all leads of all stator windings to ground.
Connect the red tester lead to the positive (+) slip
1.
ring (nearest the rotor bearing).
Diagnostic Repair Manual
44S
22S NEWER
55A
11S
4 3 2 1
9 10 11 12
0
77
004642
4
66
Testing All Stator
Testing All
Ground.
Testing All
Ground.
Testing
Ground.
Connect the black tester probe to a clean frame
2.
ground, such as a clean metal part of the rotor
shaft.
POSITIVE (+)
TEST LEAD
Figure 4-66. Testing Rotor Insulation
Turn the tester switch OFF.
3.
Plug the tester into a 120 volts AC wall socket and
4.
set the voltage switch to "1500 volts".
Turn the tester switch ON and make sure the pilot
5.
light has turned on.
Observe the breakdown lamp, then turn the tester
6.
switch OFF. DO NOT APPLY VOLTAGE LONGER
THAN ONE (1) SECOND.
If the breakdown lamp came on during the one (1)
second test, cleaning and drying of the rotor may be
necessary. After cleaning and drying, repeat the
insulation breakdown test. If breakdown lamp comes on
during the second test, replace the rotor assembly.

Cleaning the Generator

Caked or greasy dirt may be loosened with a soft brush
or a damp cloth. A vacuum system may be used to clean
up loosened dirt. Dust and dirt may also be removed
using dry, low-pressure air (25 psi maximum).
IMPORTANT NOTE: Do not use sprayed water to clean
the generator. Some of the water will be retained on
generator windings and terminals, and may cause very
serious problems.

Drying the Generator

To dry a generator, proceed as follows:
Open the generator main circuit breaker. NO
1.
ELECTRICAL LOADS MUST BE APPLIED TO
THE GENERATOR WHILE DRYING.
Provide an external source to blow warm, dry air
2.
through the generator interior (around the rotor and
stator windings. DO NOT EXCEED 185 °F. (85
°C.).
Start the generator and let it run for 2 or 3 hours.
3.
Shut the generator down and repeat the stator and
4.
rotor insulation resistance tests.
Section 4 AC Diagnostic Tests
004649
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