Generator Tests Under Load; Checking Automatic Operation - Generac Guardian Serie Manuel Du Propriétaire

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 inter-
nal temperatures to stabilize. Then, set the generator's 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 dan-
gerous and possibly fatal electrical shock.
10. Connect an accurate AC voltmeter and a frequency meter
across transfer switch terminal lugs E1 and E2. 8kW voltage
should be 230-240 volts at a frequency of 61-63 Hertz. 12,
14, 16, 17 and 20kW voltage should be 247-249 at a fre-
quency of 59.5-60.5 Hertz. 10kW voltage should be 220-230
volts at a frequency of 59.5-60.5 Hertz.
11. Connect the AC voltmeter test leads across terminal lugs E1
and neutral; then across E2 and neutral. In both cases, volt-
age reading should be 121-126 volts AC (8kW), and 125-126
volts AC (10, 12, 14, 16, 17 and 20kW).
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.
It is important not to proceed until certain that generator AC
voltage and frequency are correct and within the stated limits.
Generally, if both AC frequency and voltage are high or low,
the engine governor requires adjustment* (*GH410 only). If
frequency is correct, but voltage is high or low, the generator'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) posi-
tion.
2. Turn OFF all breakers on the load center of the transfer box (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 utility main line circuit
breaker).
Section 2 — Post Installation Start-up and Adjustments
NOTE:
Air-cooled Generators

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 electri-
cal 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 the load center of the transfer switch (T1 and T2).
10. Connect an accurate AC voltmeter and a frequency meter
across terminal lugs E1 and E2.
• 8kW voltage should be greater than 230 volts and frequency
should be greater than 58 Hz.
• 10, 12, 14, 16, 17 and 20kW voltage should be greater than
240 volts and frequency should be 60 Hz.
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 overheat-
ing, 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) posi-
tion.
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 utility power source side.
5. Turn ON the utility power supply to the transfer switch,
using the means provided (such as a utility main line circuit
breaker).
6. Set the generator's main circuit breaker to its ON (or CLOSED)
position.
7. Set the AUTO/OFF/MANUAL switch to AUTO. The system is
now ready for automatic operation.
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