"Testing All Stator Windings To Ground; Test Between Windings - Generac Power Systems 4451 & 4986 Repair Manual

section 3
DescRiption & coMponents
or DPE winding, (c) a center tapped battery charge
winding and (d) a 10 Amp center tapped battery
charge winding. Insulation tests of the stator con-
sist of (a) testing all windings to ground, (b) testing
between isolated windings, and (c) testing between
parallel windings. Figure 3-9 is a pictorial representa-
tion of the various stator leads on units with air-cooled
engine.
TESTING ALL STATOR WINDINGS TO GROUND:
1. Disconnect stator output leads Wire 11 and Wire 44 from the
generator 50A circuit breaker.
2. Remove stator output lead Wire 22 from the neutral terminal
on the back of the 50A outlet.
3. Disconnect the C1 connector from the bottom of the control
panel. See Figure 3-10. The C1 connector is on the right when
facing the control panel.
Figure 3-9. – Stator Winding Leads
4. Connect the terminal ends of Wires 11, 22, and 44 together.
Make sure the wire ends are not touching any part of the gen-
erator frame or any terminal.
5. Connect the red test probe of the Hi-Pot tester to the joined
terminal ends of stator leads 11, 22, and 44. Connect the black
tester lead to a clean frame ground on the stator can. With tes-
ter leads connected in this manner, proceed as follows:
a. Turn the Hi-Pot tester switch OFF.
b. Plug the tester cord into a 120 volt AC wall sock-
et and set its voltage selector switch to "1500
volts".
c. Turn the tester switch ON and observe the
breakdown lamp on tester. DO NOT APPLY
VOLTAGE LONGER THAN 1 SECOND. After
one (1) second, turn the tester switch OFF.
If the breakdown lamp comes on during the one-sec-
ond test, the stator should be cleaned and dried. After
cleaning and drying, repeat the insulation test. If, after
Page 14
11
44
22
11S
44S
55A
77A
2
6
55
66
77
cleaning and drying, the stator fails the second test,
the stator assembly should be replaced.
6. Now proceed to the C1 connector ( Female side – Just
removed). Each winding will be individually tested for a short
to ground. Insert a large paper clip (or similar item) into the C1
connector at the following pin locations:
pin Wire
location number
1 11S
2 44S
3 55A
4 66A
5 77A
6 2
7 6
8 55
9 66
10 77
11 4
12 0
Next refer to Steps 5a through 5c of the Hi-Pot proce-
dure.
Example: Insert paper clip into Pin 1, Hi-Pot from
Pin 1 (Wire 11S) to ground. Proceed to Pin 2, Pin
3, etc. through Pin 10.
77A
66A
2
PIN
LOCATION
6
PIN
55
LOCATION
7
6
66
Figure 3-10. – C1 Connector Pin Location Numbers
(Female Side, Located to the Right When Facing the
Control Panel)

TEST BETWEEN WINDINGS:

1. Insert a paper clip into Pin Location 3 (Wire 55A). Connect
the red tester probe to the paper clip. Connect the black tes-
ter probe to Stator Lead 11. Refer to Steps 5a through 5c of
"TESTING ALL STATOR WINDINGS TO GROUND".
2. Repeat Step 1 at Pin Location 6 (Wire 2) and Stator Lead 11.
Winding
Sense Lead Power
Sense Lead Power
Battery Charge
Battery Charge
Battery Charge
Excitation
Excitation
10 Amp Battery Charge
10 Amp Battery Charge
10 Amp Battery Charge
(Positive lead to Brush)
(Negative lead to Brush)
55A
11S
PIN
LOCATION
44S
1
PIN
LOCATION
0
77
12
4