Generac Power Systems 8 kW LP - Manual (Page 151)

OPERATIONAL TESTS
AND ADJUSTMENTS
sEctioN 5.1
sYstEm fuNctioNal tEsts
Part 5
Page 149
DANGER
+ tHE traNsfEr sWitcH is NoW ElEctri-
callY “Hot”, coNtact WitH “Hot” Parts
Will rEsult iN EXtrEmElY HaZarDous
aND PossiBlY fatal ElEctrical sHocK.
ProcEED WitH cautioN.
5. Use an accurate AC voltmeter to check utility power
source voltage across transfer switch Terminals N1 and
N2. Nominal line-to-line voltage should be 240 volts AC.
6. Check utility power source voltage across Terminals N1
and the transfer switch neutral lug; then across Terminal
N2 and neutral. Nominal line-to-neutral voltage should
be 120 volts AC.
7. When certain that utility supply voltage is compatible
with transfer switch and load circuit ratings, turn off the
utility power supply to the transfer switch.
8. On the generator panel, set the AUTO-OFF-MANUAL
switch to MANUAL. The engine should crank and start.
9. Let the engine warm up for about five minutes to allow
internal temperatures to stabilize. Then, set the generator
main circuit breaker to its “ON” (or closed) position.
DANGER
+ ProcEED WitH cautioN! GENErator
PoWEr VoltaGE is NoW suPPliED to
tHE traNsfEr sWitcH. coNtact WitH
liVE traNsfEr sWitcH Parts Will
rEsult iN DaNGErous aND PossiBlY
fatal ElEctrical sHocK.
10. Connect an accurate AC voltmeter and a frequency
meter across transfer switch Terminal Lugs E1 and E2.
Voltage should be 242-252 volts; frequency should read
about 61-63 Hertz (7/8 kW units) and about 60 Hertz on
10-20 kW units.
11. Connect the AC voltmeter test leads across Terminal
Lug E1 and neutral; then across E2 and neutral. In both
cases, voltage reading should be 121-126 volts AC.
12. Set the generator main circuit breaker to its OFF (or open)
position. Let the engine run at no-load for a few minutes to
stabilize internal engine generator temperatures.
13. Set the generator AUTO-OFF-MANUAL switch to OFF.
The engine should shut down.
note: it is important that you do not proceed until
you are certain that generator ac voltage and fre-
quency are correct and within the stated limits.
Generally, if both ac frequency and voltage are
high or low, the engine governor requires adjust-
ment. if frequency is correct, but voltage is high
or low, the generator voltage regulator requires
adjustment.
Generator teStS under load
To test the generator set with electrical loads applied,
proceed as follows:
1. Set generator main circuit breaker to its OFF (or
open) position.
2. Turn OFF all loads connected to the Transfer Switch
Terminals T1 and T2.
3. Set the generator AUTO-OFF-MANUAL switch to OFF.
4. Turn off the utility power supply to the transfer switch,
using the means provided (such as a utility main line
circuit breaker).
+ Do Not attEmPt maNual traNsfEr
sWitcH oPEratioN uNtil all PoWEr
VoltaGE suPPliEs to tHE traNsfEr
sWitcH HaVE BEEN PositiVElY turNED
off. failurE to turN off all PoWEr
VoltaGE suPPliEs Will rEsult iN
EXtrEmElY HaZarDous aND PossiBlY
fatal ElEctrical sHocK.
5. Manually set the transfer switch to the STANDBY posi-
tion, i.e., load terminals connected to the generator
E1/E2 terminals. The transfer switch operating lever
should be down.
6. Set the generator AUTO-OFF-MANUAL switch to
MANUAL. The engine should crank and start immediately.
7. Let the engine stabilize and warm up for a few minutes.
8. Set the generator main circuit breaker to its ON (or
closed) position. Loads are now powered by the standby
generator.
9. Turn ON electrical loads connected to transfer switch T1
and T2. Apply an electrical load equal to the full rated
wattage/amperage capacity of the installed generator.
10. Connect an accurate AC voltmeter and a frequency
meter across Terminal Lugs E1 and E2.
a. 7/8kW voltage should be greater than 230 volts
and frequency should be greater than 58 Hz.
b. 10-20 kW voltage should be greater than 240
volts and frequency should be
60 Hz.