SUPPORT AS 2277974 - Caterpillar

Return To NORMAL Bypass (For Use With In-Phase Monitor Controls)
The Return To NORMAL Bypass option that can be used with the In-Phase Monitor Control does not work in the same manner as the Return To NORMAL Bypass option which is used with the standard Microprocessor Based Control. The In-Phase Monitor Control gives the operator the ability to transfer the load back to the normal power source after normal power is restored thus bypassing the Return To Utility timer. To bypass the Return To Utility timer, the operator should press switch SW4 (normally open). The circuit board will then cause the transfer mechanism to switch the load to the normal power source. SW4 is mounted on the front of the door panel of the Automatic Transfer Switch enclosure.Preferred Source Selector Switch
This option may be used when it is desirable for either source of power to serve as the normal (preferred) source. The other power source then becomes the standby source. The preferred source selector (PSS) switch: is mounted to the door, is manually operated, AND has two positions (SOURCE #1 and SOURCE #2). The PSS switch connects to the transfer switch, to provide a means of selecting the normal (preferred) source.The PSS switch is shown above in the SOURCE #1 position. In this position, UNIT #1 is the preferred source and UNIT #2 is the standby source. The PSS switch shorts wires #253 and #254 together, which provides the signal to start and run UNIT #1. If SOURCE #1 fails with the PSS switch in the SOURCE #1 position, the transfer switch signals the standby power source (UNIT #2) to start.When the PSS switch is in the SOURCE #2 position, UNIT #2 is the preferred source and UNIT #1 is the standby source. In this position, wire #199 is opened and therefore the control system (Microprocessor, In-Phase Monitor or Programmable Logic) thinks SOURCE #1 is not available. The transfer relay (TR) is energized and contacts 2 & 8 are open. The PSS switch shorts wires #178 and #183 together, which provides the signal to start and run UNIT #2. If SOURCE #2 fails with the PSS switch in the SOURCE #2 position; transfer relay (TR) de-energizes and contacts 2 & 8 close, and the transfer switch signals the standby power source (UNIT #1) to start.Transfer Contact-Elevator (For Use With Microprocessor Based Controls)
The optional Transfer Contact-Elevator provides a time delay, which permits elevators to continue operating (long enough to reach the next floor) before a transfer to another power source can occur. Without this optional time delay, the loss of power that occurs during any transfer action could result in elevator(s) stopping between floors. This option consists of Relays SR1 and TD1, which are energized by NORMAL source voltage; and Relays SR2 and TD2, which are energized by STANDBY source voltage.The TD1, SR1 or TD2, SR2 relays delay the operation of the transfer switch for their preset time. Two sets of contacts are provided to signal the elevator prior to