The transfer switch provides a special circuit that de-energizes the motor control circuit five (5) seconds prior to transfer in either direction to prevent high current transients due to an out-of-phase condition between the motor and the source to which it is being connected. A contact is provided to actuate the engine starting circuit when normal source fails. To prevent false starts, a time delay (factory set at ? to 3 seconds) is provided between normal source failure and actuation of the engine start contact. An isolation switch ahead of the alternate source input terminals of the transfer switch is provided. When the switch is opened, auxiliary contacts in the generator start circuit prevent starting if commanded to by the transfer switch. An additional auxiliary contact on the isolation switch is provided for remote annunciation of isolation switch position. An adjustable time delay (0-30 minutes) prevents restoration to normal service for a preset period of time to assure normal line stabilization.An auxiliary N.O. contact is provided for remote annunciation of transfer to emergency. This contact is operated by the transfer mechanism as a direct indication of switch position. LED's located on the controller OID indicate the transfer switch position, either normal or emergency. An additional LED is provided to indicate the Emergency Isolation Switch is in the OFF position.
|Application||Fire Protection System|
|Type||Automatic Transfer Switch|