Product Manual

TP-6946 3/16 65Section 7 Changing the Service Disconnect Position
7.2.2 Procedure to Disconnect th e
Engine Start Bypass Circuit
Transfer switches using the new transformer
assemblies include an engine start bypass circuit that
prevents the ATS from sending an engine start signal to
the generator when it is placed in the Service
Disconnect position. If it is necessary to configure the
ATS to operate in the Service Disconnect to Emergency
position, this bypass circuit must be disconnected from
the controller’s input connection.
After performing this procedure, programmable output
#1 is available for customer use, if needed.
Programmable output #1 has been factory-set to
Service Disconnect Generator Control. Be sure to reset
the output to the appropriate event if connecting it to
customer equipment.
Hazardous voltage.
Will cause severe injury or death.
Only authorized personnel should
open the enclosure.
DANGER
Accidental starting.
Can cause severe injury or death.
Disconnect the battery cables before
working on the generator set.
Remove the negative (--) lead first
when disconnecting the battery.
Reconnect the negative (--) lead last
when reconnecting the battery.
WARNING
Servicing the transfer switch. Hazardous voltage can
cause severe injury or death. Deenergize all power sources
before servicing. Turn off the main circuit breakers of all
transfer switch power sources and disable all generator sets
as follows: (1) Move all generator set master controller
switches to the OFF position. (2) Disconnect power to all
battery chargers. (3) Disconnect all battery cables, negative
(--) leads first. Reconnect negative (--) leads last when
reconnecting the battery cables after servicing. Follow these
precautions to prevent the starting of generator sets by an
automatic transfer switch, remote start/stop switch, or engine
start command from a remote computer. Before servicing any
components inside the enclosure: (1) Remove all jewelry. (2)
Stand on a dry, approved electrically insulated mat. (3) Test
circuits with a voltmeter to verify that they are deenergized.
See Figure 7-5 and follow these instructions.
1. Prevent the generator set from starting:
a. Press the OFF button on the generator
controller.
b. Disconnect power to the generator engine
starting battery charger, if installed.
c. Disconnect all generator engine start battery
cables, negative (--) leads first.
2. To remove power from the ATS controller, follow
the instructions in Section 6 to perform the service
disconnect procedure and the control circuit
isolation procedure.
3. Open the ATS enclosure door and find the
programmable output connections to TB1 on the
back of the Decision-Makerr MPAC 1500
controller.
4. Engine start bypass circuit leads 4B and 4D are
connected to programmable output #1, terminals
TB1-5 and TB1-6 o n the controller’s main logic
circuit board. Disconnect leads 4B and 4D from the
controller.
5. Connect leads 4B and 4D together and tape
securely.