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6 Generac
®
Power Systems, Inc.
3.3 TRANSFER SWITCH VOLTAGE
CHECKS
1. Turn ON the UTILITY power supply to the transfer
switch with whatever means provided (such as the
UTILITY main line circuit breaker).
Proceed with caution. The transfer switch is now
electrically hot. Contact with live terminals
results in extremely hazardous and possibly fatal
electrical shock.
2. With an accurate AC voltmeter, check for correct
voltage across terminal lugs N1 and N2; N1 to NEU-
TRAL; and, finally, N2 to NEUTRAL (see Wiring
Diagram on Page 8).
3. When certain that UTILITY supply voltage is correct
and compatible with transfer switch ratings, turn
OFF the UTILITY supply to the transfer switch.
4. On the generator panel, set the Auto-Off-Manual
switch to MANUAL position. The generator should
crank and start.
5. Let the generator stabilize and warm up at no-load
for at least five minutes.
6. Set the generator’s main circuit breaker (CB1) to its
ON or CLOSED position.
Proceed with caution. Generator output voltage
is now being delivered to transfer switch termi-
nals. Contact with live terminals results in
extremely dangerous and possibly fatal electrical
shock.
7. With an accurate AC voltmeter and frequency meter,
check the no-load, voltage and frequency meter at
transfer switch terminal lugs E1, E2 and NEUTRAL.
Readings should be as follows:
a. Frequency................................61-63 Hz
b. Terminals E1 and E2..............242-253 volts
c. Terminal E1 to Neutral ..........121-126 volts
d. Terminal E2 to Neutral ..........121-126 volts
8. Set the generator’s main circuit breaker (CB1) to its
OFF or OPEN position.
9. To shut down the generator, set its Auto-Off-Manual
switch to its OFF position.
NOTE:
Do NOT proceed until generator AC output voltage
and frequency are correct and within stated lim-
its. If the no-load voltage is correct but no-load
frequency is incorrect, the engine governed speed
probably requires adjustment. If no-load frequen-
cy is correct but voltage is not, the voltage regu-
lator may require adjustment.
3.4 GENERATOR TESTS UNDER LOAD
1. Set the generator’s main circuit breaker to its OFF
or OPEN position.
2. Turn OFF utility power to the transfer switch.
3. Manually move the transfer switch main contacts to
their STANDBY position.
4. To start the generator, set the Auto-Off-Manual
switch to MANUAL. When engine starts, let it stabi-
lize for a few minutes.
5. Turn the generator’s main circuit breaker to its ON
or CLOSED position. The generator now powers all
LOAD circuits. Check generator operation under
load as follows:
• Turn ON electrical loads to the full rated
wattage/amperage capacity of the generator. DO
NOT OVERLOAD.
• With maximum rated load applied, check voltage
and frequency across transfer switch terminals E1
and E2. Voltage should be greater than 230 volts;
frequency should be greater than 58 Hz.
• Let the generator run under rated load for at least
30 minutes. With the unit running, listen for
unusual noises, vibration, overheating, etc., that
might indicate a problem.
6. When checkout under load is complete, set the gen-
erator’s main circuit breaker to its OFF or OPEN
position.
7. Let the generator run at no-load for several minutes.
Then, shut down by setting the Auto-Off-Manual
switch to its OFF position.
8. With the manual transfer handle, move the switch’s
main contacts back to their utility position, i.e., load
connected to utility power supply. The handle and
operating lever of the transfer switch should be in
the up position.
9. Turn on the utility power supply to the transfer
switch, using whatever means provided (such as a
utility main line circuit breaker). The utility power
source now powers the loads.
10. Set the generator’s main circuit breaker to its ON or
CLOSED position.
11. Set the generator’s Auto-Off-Manual switch to its
AUTO position. The system is now set for fully
automatic operation.
DANGER
DANGER
Section 3 — Post Installation Start-Up Adjustments
Generac 100 Amp Transfer Switch