4 generator tests under load, 5 checking automatic operation – Generac Power Systems 04390-1 User Manual

Page 13

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Generac

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Power Systems, Inc.

11

10. Connect an accurate AC voltmeter and a frequen-

cy meter across transfer switch terminal lugs E1
and E2. Voltage should be 242-252 volts; fre-
quency should read about 61-63 Hertz.

11. Connect the AC voltmeter test leads across termi-

nal lug E1 and neutral; then across E2 and neu-
tral. In both cases, voltage reading should be 121-
126 volts AC.

12. Set the generator’s 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's Auto/Off/Manual switch to

OFF. The engine should shut down.

NOTE:

It is important not to proceed until you are certain
that generator AC voltage and frequency are cor-
rect and within the stated limits. Generally, if both
AC frequency and voltage are high or low, the
engine governor requires adjustment. If frequency
is correct, but voltage is high or low, the genera-
tor’s voltage regulator requires adjustment.

2.4

GENERATOR TESTS UNDER LOAD

To test the generator set with electrical loads applied,
proceed as follows:

1. Set generator’s 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's Auto/Off/Manual switch to OFF.
4. Turn OFF the utility power supply to the transfer

switch, using the means provided (such as a util-
ity main line circuit breaker).

Do not attempt manual transfer switch opera-
tion 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

position, i.e., load terminals connected to the
generator's E1/E2 terminals. The transfer switch
operating lever should be down.

6. Set the generator's 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’s 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 frequen-

cy meter across terminal lugs E1 and E2. Voltage
should be greater than 230 volts; frequency
should be greater than 58 Hertz.

11. Let the generator run at full rated load for 20-30

minutes. Listen for unusual noises, vibration or
other indications of abnormal operation. Check
for oil leaks, evidence of overheating, etc.

12. When testing under load is complete, turn OFF

electrical loads.

13. Set the generator's main circuit breaker to its

OFF (or open) position.

14. Let the engine run at no-load for a few minutes.
15. Set the Auto/Off/Manual switch to OFF. The

engine should shut down.

2.5

CHECKING AUTOMATIC
OPERATION

To check the system for proper automatic operation,
proceed as follows:

1. Set generator’s main circuit breaker to its OFF

(or open) position.

2. Check that the Auto/Off/Manual switch is set to

OFF.

3. Turn OFF the utility power supply to the transfer

switch, using means provided (such as a utility
main line circuit breaker).

4. Manually set the transfer switch to the UTILITY

position, i.e., load terminals connected to the util-
ity power source side.

5. Turn ON the utility power supply to the transfer

switch, using the means provided (such as a util-
ity main line circuit breaker).

6. Set the Auto/Off/Manual switch to AUTO. The sys-

tem is now ready for automatic operation.

7. Turn OFF the utility power supply to the transfer

switch.

With the Auto/Off/Manual switch at AUTO, the engine
should crank and start when the utility source power
is turned OFF. After starting, the transfer switch
should connect load circuits to the standby side. Let
the system go through its entire automatic sequence
of operation.

With the generator running and loads powered by
generator AC output, turn ON the utility power sup-
ply to the transfer switch. The following should
occur:

• After about six seconds, the switch should transfer

loads back to the utility power source.

• About one minute after retransfer, the engine

should shut down.

Section 2 — Post Installation Start-up and Adjustments

Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators

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