Emerson 381333230 Section Sequence of Operation, Transfer To Emergency, Retransfer to Normal

SECTION 2

SEQUENCE OF OPERATION

Controller Code 1

Refer to Section 5, Optional Accessories for additional control functions.

Refer to Wiring Diagram furnished with the ASCO 386. Note Control Features furnished on this switch, and review operation.

	Transfer
	Control
Transfer	Transfer
To	To
Normal	Emergency

Transfer To Emergency

The sequence for load transfer to the emergency source begins when you turn the door-mounted Transfer Control switch clockwise to the Transfer To Emergency position.

When the Transfer Control switch is operated to Transfer To Emergency, the voltage and frequency sensor begins monitoring the emergency source. The sensor will accept the emergency source only when both voltage and frequency reach 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.

The transfer switch will remain in the Emergency position until the Transfer Control switch is operated to the Transfer To Normal position.

	Transfer
	Control
Transfer	Transfer
To	To
Normal	Emergency

Retransfer to Normal

The sequence for load retransfer to the normal source begins when you turn the door-mounted Transfer Control switch counterclockwise to the Transfer To Normal position.

When the Transfer Control 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.

The transfer switch will remain in the Normal position until the Transfer Control switch is operated to the Transfer To Emergency 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.

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