Generac Power Systems 20 kW LP ユーザーズマニュアル
240 VAC
N1
N2
TEST POINTS
Figure 9. Terminal Block Test Points
teSt 37 – check utility SenSinG
VoltaGe at the circuit Board
DISCUSSION:
If the generator starts and transfer to STANDBY
occurs in the automatic mode when acceptable
UTILITY source voltage is available at the terminal
block, the next step is to determine if sensing voltage
is reaching the printed circuit board.
note: the System ready led will flash in auto or
utility loSt will display on the panel.
If the generator starts and transfer to STANDBY
occurs in the automatic mode when acceptable
UTILITY source voltage is available at the terminal
block, the next step is to determine if sensing voltage
is reaching the printed circuit board.
note: the System ready led will flash in auto or
utility loSt will display on the panel.
PROCEDURE:
1. Set the AUTO-OFF-MANUAL switch to OFF.
2. Disconnect the N1/N2 connector in the control panel
2. Disconnect the N1/N2 connector in the control panel
(see Figure 6).
3. Set a VOM to measure AC voltage.
4. Connect one meter test lead to Wire N1. Connect the
4. Connect one meter test lead to Wire N1. Connect the
other meter test lead to Wire N2. Approximately 240
VAC should be measured. See Figure 9.
RESULTS:
1. If voltage was measured in Step 4 and the pin connec-
tions are good, replace the circuit board.
2. If voltage was NOT measured in Step 4, repair or replace
Wire N1/N2 between connector and terminal block.
teSt 38 – check utility SenSe VoltaGe
The N1 and N2 terminals in the transfer switch deliver
utility voltage “sensing” to a circuit board. If voltage at
the terminals is zero or low, standby generator startup
and transfer to the “Standby” source will occur auto-
matically as controlled by the circuit board. A zero
or low voltage at these terminals will also prevent
retransfer back to the “Utility” source.
utility voltage “sensing” to a circuit board. If voltage at
the terminals is zero or low, standby generator startup
and transfer to the “Standby” source will occur auto-
matically as controlled by the circuit board. A zero
or low voltage at these terminals will also prevent
retransfer back to the “Utility” source.
PROCEDURE:
With utility source voltage available to terminal lugs
N1 and N2, use a VOM to test for utility source line-
to-line voltage across terminal locations N1 and N2
terminals. Normal line-to-line utility source voltage
should be indicated.
With utility source voltage available to terminal lugs
N1 and N2, use a VOM to test for utility source line-
to-line voltage across terminal locations N1 and N2
terminals. Normal line-to-line utility source voltage
should be indicated.
N2
N1
N1A N2A
F1
F2
F3
A
A
A
B
B
B
T1
Figure 10. Transfer Switch Fuse Block
RESULTS:
1. If voltage reading across the N1 and N2 terminals is
zero or low, refer to Flow Chart.
2. If voltage reading is good, refer to Flow Chart.
teSt 39 – check VoltaGe at terminal
luGS n1, n2
DISCUSSION:
If source voltage is not available to N1/N2 terminals,
automatic startup and transfer to STANDBY will occur
when the generator AUTO-OFF-MANUAL switch is
set to AUTO. This test will prove that “Utility” voltage is
available to those terminals, or is not available.
If source voltage is not available to N1/N2 terminals,
automatic startup and transfer to STANDBY will occur
when the generator AUTO-OFF-MANUAL switch is
set to AUTO. This test will prove that “Utility” voltage is
available to those terminals, or is not available.
*
DaNGEr: ProcEED WitH cautioN! HiGH
aND DaNGErous VoltaGEs arE PrEsENt
at tErmiNal luGs N1/N2. coNtact WitH
HiGH VoltaGE tErmiNals Will rEsult
iN DaNGErous aND PossiBlY lEtHal
ElEctrical sHocK. Do Not attEmPt
tHis tEst WHilE staNDiNG oN WEt or
DamP GrouND, WHilE BarEfoot, or
WHilE HaNDs or fEEt arE WEt.
at tErmiNal luGs N1/N2. coNtact WitH
HiGH VoltaGE tErmiNals Will rEsult
iN DaNGErous aND PossiBlY lEtHal
ElEctrical sHocK. Do Not attEmPt
tHis tEst WHilE staNDiNG oN WEt or
DamP GrouND, WHilE BarEfoot, or
WHilE HaNDs or fEEt arE WEt.
PROCEDURE:
1. Make sure that all main line circuit breakers in the utility
line to the transfer switch are “On” or “Closed.”
Page 84
Part 3
TRANSFER SWITCH
sEctioN 3.4
DiaGNostic tEsts