Filter
Top Products
SECTION 2
SEQUENCE OF OPERATION
2 --- 1
Controller Code 1
Refer to Section 5, Optional Accessories for a dditional control functions.
Refer to Wiring Diagram furnished with the ASCO 386. Note Control Features furnished on this switch, and review operation.
Transfer
Control
Transfer
To
Normal
Transfer
To
Emergency
Transfer To Emergency
The sequence for load transfer to the emergency
source begins when you turn the door-mounted
Tran sfer Con tro l switch clockwise to the Transfer To
Emergency position.
When the Transfer Contro l switch is operated to
Tr a ns fer To Emergenc y, the voltage and frequency
sensor begins monitoring the emergency source.
The sensor will accept the emergency source only
when both
voltage and frequency r each preset
pickup points. If the emergency source is available
immediately, the sensor may accept it as soon as
the Transfer Control switch is operated.
When the emergency source is accepted by the
sensor, relay ER picks up to transfer the load to
the emergency source.
ER relay energizes, the TS coil is energized, the
transfer switch operates, and all switch contacts
(mains, controls, auxiliaries) reverse position.
The transfer switch is now supplying the load from
the emergency source.
ThetransferswitchwillremainintheEmergency
position until the Transfer Con tro l switc h is
operated to the Transfer To Normal position.
Transfer
Control
Transfer
To
Normal
Transfer
To
Emergency
Retransfer to Normal
The sequence for load retransfer to the normal
source begins when you turn the door-mounted
Tran sfer Control switch counterclockwise to the
Transfer To Normal position.
When the Transfer Contro l switch is operated to
Transfer To Normal, the voltage sensor begins
monitoring the normal source.
The SE relay energizes when the sensor accepts
the normal source voltage.
SE relay energizes. The TS coil is energized, the
transfer switch operates, and all switch contacts
(mains, controls, auxiliaries) reverse position.
The transfer switch is now supplying the load from
the normal source again.
The SE relay de–energizes when the Transfer
Control switch is released.
ThetransferswitchwillremainintheNormal
position until the Transfer Control switch is
operated to the Tr a ns fer To Emergenc y position.
Note
Activation of standard control features
shown in Section 5 will alter the sequence of
operation and introduce additional time
delays during transfer operations.