Product Manual

TP-6946 3/16 47Section 6 Operation
Section 6 Operation
6.1 Transfer Switch Operation
6.1.1 Normal Operation
Under normal conditions, the load is energized from the
utility supply through the closed utility transfer power
switching device. If the utility power fails, the generator
will start and the load will be reenergized via the closed
generator transfer power switching device. Refer to the
controller operation manual for the sequence of
operation.
In the normal operating mode, the service disconnect
switch must be in the AUTO position. See Section 6.4 or
Section 6.3 for service disconnect instructions.
6.1.2 Overcurrent Trip
If the utility source power switching circuit breaker trips
open due to an overcurrent condition, the ATS controller
will initiate an engine start signal and initiate transfer of
the load to the generator supply. A Source1 breaker trip
fault will be displayed on the ATS controller. The utility
source will be locked out and the load will remain on the
generator supply until the fault is manually reset.
If the emergency source power switching circuit breaker
trips open due to an overcurrent condition, the load is
transferred to the utility supply. A Source2 breaker trip
fault will be displayed on the ATS controller. The
generator source will be locked out and the load will
remain on the utility supply until the fault is manually
reset.
If the emergency source power switching circuit breaker
trips open during a loaded test or exercise sequence,
the load is transferred to normal and the test or exercise
sequence ends.
Note: Contact your local distributor/dealer to identify
and correct the cause of the overcurrent
condition before resetting the fault.
Press the RESET button on the breaker to reset the
breaker on ICCB models. Then check the controller
display for fault messages. See the ATS controller
operation manual for instructions to reset the fault. See
the List of Related Materials in the Introduction section
for the manual part number.
MCCB type breakers will automatically reset when the
controller fault is reset and the transfer switch controller
initiates transfer to the other source.
6.2 Service Disconnect Position
Model KEP Service Entrance rated transfer switches
are configured with the service disconnect position set
to either Emergency or OFF. The service disconnect
position is factory set on the Decision-Makerr
MPAC 1500 controller. Units that are factory-configured
to use the OFF position are identified on the service
disconnect switch decal, shown in Figure 6-1. Units that
do not have the Service Disconnect to OFF label shown
in Figure 6-1 use the Emergency position.
The two styles require different procedures to
disconnect power during maintenance or service.
6.2.1 Service Disconnect to Emergency
When the service disconnect switch is moved to the
SERVICE DISCONNECT position, the transfer switch
signals the generator set to start and transfers to the
Emergency source. See Section 6.3 for service
disconnect procedures for transfer switches with
the service disconnect to Emergency position.
Controllers with MPAC firmware versions earlier than
1.10 use the Service Disconnect to Emergency position.
The service disconnect position is not displayed on
controllers with firmware versions earlier than 1.10.
6.2.2 Service Disconnect to OF F
When the service disconnect switch is moved to the
SERVICE DISCONNECT position, the utility breaker
opens. Utility power is disconnected and the ATS is in
the OFF position. See Section 6.4 for service
disconnect procedures for transfer switches with
the service disconnect to OFF position.
Controllers with MPAC firmware version 1.10 or higher
are factory set with the Service Disconnect to OFF
position. The position can be seen in the View System
Setup screen on the controller. See the controller
operation manual for instructions to view the system
setup, if necessary.
NOTICE:
SERVICE DISCONNECT TRANSFERS
TO OFF, REMOVING POWER FROM
THE LOAD. POWER WILL NOT BE
RESTORED UNTIL THE SWITCH IS
RETURNED TO AUTO.
GM99262
Figure 6-1 Service Disconnect to OFF Label