3.3.3
LOAD TRANSFER
The transfer of load when the generator is running is dependent
upon the operating mode as follows:
1.
Manual
– Will not transfer to generator if utility is present.
– Will transfer to generator if utility fails (below 65% of nominal for
10 consecutive seconds.
– Will transfer back when utility returns for 15 consecutive sec-
onds. The engine will continue to run until removed from the
Manual mode.
2.
Auto
– Will start and run if Utility fails for 10 consecutive seconds.
– Will start a five (5) second engine warm-up timer.
– Will not transfer if utility subsequently returns.
– Will transfer to generator if utility is still not present.
– Will transfer back to utility once utility returns (above 75% of
nominal) for 15 seconds.
– Will transfer back to utility if the generator is shut down for any
reason (such as the switch is in the OFF position or a shutdown
alarm.
– After transfer, will shut down engine after one (1) minute cool-
down time.
3.
Exercise
– Will not exercise if generator is already running in either Auto or
Manual mode.
– During exercise, the controller will only transfer if utility fails
during exercise for 10 seconds, and will switch to Auto mode.
3.3.4
UTILITY RESTORED
Initial Condition: Generator supplying power to customer load.
When the utility returns (above 80% of nominal), a 15 second
return to utility timer will start. At the completion of this timer, if
the utility supply is still present and acceptable, the control will
transfer the load back to the utility and run the engine through a
one (1) minute cool down period and then shut down. If utility fails
for three (3) seconds during this cool down period, the control
will transfer load back to the generator and continue to run while
monitoring for utility to return.
3.4
MANUAL TRANSFER
OPERATION
3.4.1
TRANSFER TO GENERATOR POWER SOURCE
To start the generator and activate the transfer switch manually,
proceed as follows:
1.
Set the generator's AUTO/OFF/MANUAL switch to OFF.
2.
Set the generator's main circuit breaker to its OFF (or OPEN)
position.
3.
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 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 pos-
sibly fatal electrical shock.
4.
Use the manual transfer handle inside the transfer switch to
move the main contacts to their STANDBY position, i.e., loads
connected to the standby power source (Figure 3.2).
5.
To crank and start the engine, set the AUTO/OFF/MANUAL
switch to MANUAL.
6.
Let the engine stabilize and warm up for a few minutes.
7.
Set the generator's main circuit breaker to its ON (or CLOSED)
position. The standby power source now powers the loads.
Figure 3.2 – Manual Transfer Switch Operation
3.4.2
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 fol-
lows:
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 pos-
sibly fatal electrical shock.
Operation
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