Figure 3.2 – Manual Transfer Switch Operation
3.5.2 TRANSFER BACK TO UTILITY POWER
SOURCE
When utility power has been restored, transfer back
to that source and shut down the generator. This can
be accomplished as follows:
1. Set the generator’s main circuit breaker to its
OFF (or open) position.
2. Let the engine run for a minute or two at no-load
to stabilize the internal temperatures.
3. Set the generator’s AUTO/OFF/MANUAL switch to
its OFF (or open) position. The engine should
shut down.
4. Check that utility power supply to the transfer
switch is turned OFF.
Do not attempt to activate the transfer switch
manually until all power voltage supplies
to the switch have been positively turned off.
Failure to turn off all power voltage supplies
may result in extremely hazardous and possibly
fatal electrical shock.
5. Use the manual transfer handle inside the trans-
fer switch to move the main contacts back to their
“Utility” position, i.e., loads connected to the util-
ity power source (Figure 3.2).
6. Turn ON the utility power supply to the transfer
switch using the means provided.
7. Set the system to automatic operation as outlined
in “Automatic Transfer Operation,” Section 3.3.
3.6 SETTING THE EXERCISE TIMER
The generator is equipped with an exercise timer.
Once it is set, the generator will start and exercise
once every seven days, on the day of the week and at
the time of day the following sequence is completed.
During this exercise period, the unit runs for approx-
imately 12 minutes and then shuts down. Transfer of
loads to the generator output does not occur during
the exercise cycle.
A switch on the control panel (see Figure 3.1) permits
selection of the day and time for system exercise. To
select the desired day and time of day, the following
sequence must be performed at that time.
1. Verify that the AUTO/OFF/MANUAL switch is set
to AUTO.
2. Hold down the set timer switch until the genera-
tor starts (approximately 10 seconds) and then
release.
3. The generator will start and run for approximately
12 minutes and then shut down on its own. The
exerciser will then be set to run at that time of day
every week.
NOTE:
The exerciser will only work in the AUTO mode
and will not work unless this procedure is per-
formed. The exerciser will need to be reset every
time the 12-volt battery is disconnected and then
reconnected. The exerciser WILL NOT work if dip
switch 2 (Remote Not Auto) on the controller
printed circuit board is ON.
3.7 PROTECTION SYSTEMS
3.7.1 LOW OIL PRESSURE SWITCH
This switch (Figure 3.3) has normally closed contacts
that are held open by engine oil pressure during crank-
ing and operating. Should oil pressure drop below the
8 psi range, switch contacts close, and the engine
shuts down. The unit should not be restarted until oil
is added, and the AUTO/OFF/MANUAL switch must be
turned to OFF and then back to AUTO.
3.7.2 HIGH TEMPERATURE SWITCH
This switch’s contacts (Figure 3.3) close if the tem-
perature should exceed approximately 140º C (284º
F), initiating an engine shutdown. The generator will
automatically restart and the LED will reset once the
temperature has returned to a safe operating level.
DANGER
Section 3 — Operation
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators
16 Generac
®
Power Systems, Inc.