Generac Power Systems 53187 - Manual (Page 50)

SECTION 1.8
INSULATION RESISTANCE TESTS 1 PARTI
THE REVOLVING FIELD AC GENERATOR
Testing Stator Insulation Resistance
To test tne resistance of stator insulation, proceed
as follow s:
1. To test all stator leads to ground:
a. Connect the ends of stator leads 11,22,33,44,2,
5 and 6 together. Make sure none of the w i re term inal
ends are touching any part of the generator.
b. Connect the red test lead of the Hi-Pot Tester to
the bunched term inal ends of W ires 11, 22, 33, 44,
2, 5 and 6.
c. Connect the black test lead of the Hi-Pot Tester to
a clean fram e ground on the stator.
d. Turn the Hi-Pot Tester Sw itch OFF.
e. Plug the Hi-Pot Tester into a 120 volts AC w all
P0Q 0 pt3cl6 •
f. Set the Tester’s Voltage Sw itch to "SOO' volts.
g. Turn the Hi-Pot Tester sw itch ON. Check that the
Tester’s Pilot lam p is ON.
h. Set the Tester Voltage Sw itch to ''2000" volts and
w atch the "Breakdow n' lam p. After 1 second, turn
the Tester sw itch OFF and reset Voltage sw itch to
"500" volts. DO NOT APPLY VOLTAGE LONGER
THAN 1 SECOND.
2. To test betw een isolated w indings:
a. Connect the red Tester lead to term inal end of
stator lead No. 2. Connect the black tester lead to
term inal end of stator lead No. 11.
b. Turn the Tester sw itch to ON (Pilot lam p should
com e ON).
c. Set the Voltage Selector sw itch to "1500" volts.
APPLY
VOLTAGE FOR ONE SECOND ONLY
W HILE OBSERVING THE "BREAKDOW N" LAMP.
d. Turn the Tester sw itch to OFF and reset the
Voltage sw itch to "500" volts.
3. To test betw een parallel w indings:
a. Connect the red tester lead to term inal end of
stator lead No. 11; the black tester lead to term inal
end of stator lead No. 33.
b. Turn the tester sw itch to ON (pilot lam p should
com e ON).
c. Set the Voltage Selector sw itch to "500" volts.
APPLY VOLTAGE FOR ONE SECOND W HILE OB­
SERVING THE "BREAKDOW N" LAMP. After one
second, turn the tester sw itch to "Off".
If the tester "Breakdow n" lam p cam e on during any
one second test, clean and dry the stator. Then, repeat
the insulation breakdow n test. If the "Breakdow n" lam p
illum inates during the second test, replace the stator
assem bly.
Testing Rotor Insulation
Before testing the Rotor, m ake sure brushes and
brush holders are rem oved and Rotor is com pletely
isolated from ground and from other com ponents.
Disconnect excitation leads No. 1 and 4 from the
brushes. Rem ove the brush holders w ith brushes.
Make sure Rotor is com pletely isolated from fram e
ground.
CAUTION: Rotor must be completely Isolated
from the Voltage Reoulator. Brush Wires No. 1
and 4 must not touch any part of frame during
the test, or damage to the Regulator will result.
1. Connect the red test lead to the positive (+) slip ring.
This is the slip ring nearest the Rotor bearing.
2. Connect the tester black lead to a clean fram e ground
on the Rotor.
3. Turn the Tester sw itch OFF.
4. Plug the tester into a 120 volts AC w all receptacle.
5. Set the Tester Voltage sw itch to "500" volts.
6. Turn the tester ON and check that the Pilot lam p is
ON.
7. Set the tester Voltage sw itch to "1250" volts. W ait
one (1) second, then turn the tester sw itch OFF. DO
NOT APPLY VOLTAGE LONGER THAN ONE SEC­
OND.
If the tester "Breakdow n" lam p com es on during the
one second test, cleaning and drying m ay be neces­
sary. After cleaning and drying, repeat the insulation
breakdow n test. If "Breakdow n" lam p com es on during
the second test (after cleaning and drying), replace the
Rotor.
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