Sequence Of Operation, Closed Transition Models; Preferred Source Loss And Return, Closed-Transition; Failure To Synchronize (Programmed-Transition Override) - Kohler MPAC 1500 Manual

3.9 Sequence of Operation,
Closed-Transition Models
Closed-transition transfer switches operate with no
interruption of power to the load during transfer when
both sources are available. The controller monitors the
sources for synchronization before initiating transfer.
Sources are paralleled for less than 100 milliseconds
during transfer.
3.9.1 Preferred Source Loss and
Return, Closed Transition
Preferred Source Fails
1. Load control contacts open.
2. Engine start time delay runs and expires.
3. The generator is signaled to start (engine start
contacts close).
4. The generator starts and the standby source
becomes available.
5. Preferred-to-standby time delay expires.
6. Preferred source contacts open.
7. Off-to-standby time delay expires.
8. Emergency power contacts close.
9. Post-transfer load control sequences run and load
control contacts close, as programmed through the
Load Add settings.
Preferred Source Returns
1. Standby-to-preferred and pre-transfer load control
time delays expire.
2. Load control contacts open according to the Load
Disconnect time delay settings.
3. Check/wait for source synchronization.
Note: If the sources do not synchronize before the
Fail to Sync time delay expires, the
programmed-transition override function
operates. See Section 3.9.2.
4. When sources are synchronized, preferred source
contacts close.
5. Standby source contacts open within 100
milliseconds.
32 Section 3 Operation
Note: If the standby source contacts do not open
within 100 ms, the extended transfer time
relay trips the standby source breaker.
6. Post-transfer load control sequences and engine
cooldown time delay expire.
7. Load control contacts close as programmed
through the Load Add settings.
8. The generator is signaled to stop (engine start
contacts open).
3.9.2 Failure to Synchronize
(Programmed-Transition Override)
If the sources do not synchronize before the Fail to Sync
time delay expires, the programmed-transition override
function can initiate a transfer. The override function
transfers to the other source using programmed-
transition mode, which causes an interruption in power
to the load during transfer. The contactor stops in the Off
position for a programmed period of time, which is set by
the off-to-preferred or off-to-standby time delay. The
override function can be set to operate automatically or
to require manual activation.
D
If Automatic programmed-transition override is
selected, a programmed-transition transfer will be
initiated automatically when the Fail to Sync time
delay expires.
D
If Manual programmed-transition
selected, an operator can initiate a programmed-
transition transfer by entering the setup password
and pressing a button after the Fail to Sync time delay
expires. If a manual transfer is not initiated, the
controller continues to monitor the sources and
transfers if synchronization occurs.
See Section 5.14,
programmed-transition override function to automatic or
manual. See Section 5.9, Time Delays, to set the
off-to-preferred and off-to-standby time delays.
Programmed-Transition Override Sequence
1. Fail to Sync time delay expires.
2. If Automatic programmed-transition override is
enabled, go to step 4.
3. If manual programmed-transition override is
enabled, the Manual Transfer screen opens. The
operator enters the setup password and manually
initiates programmed-transition transfer.
override
Set System, to set
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