The ARA-120-AJE Alternating Relay with Sequence Locking Switch is a special function triplexer alternating relays are designed three-load installations. This unit has a field selection switch that is used to lock the alternating relay into a desired sequence. The model ARA-120-AJE Alternating Relay with Sequence Locking Switch has the option of automatically alternating on each load cycle or by external clocking, while allowing for additional loads to run in the event of excess load requirements.
The alternating action is initiated by the control switch between terminals 2 and 4 when the factory installed jumper is in place between terminals 3 and 4. The alternating action may be initiated externally by removing the factory installed jumper between terminals 3 and 4 and placing an isolated normally open switch between terminals 2 and 3. The alternating action will occur each time this isolated switch is closed and then re-opened. A four-position rotary switch has been incorporated to permit field selection of the sequence to be maintained.
The selection switch has the following positions: Normal — Normal operation as a triplexer Lock 1 — Locks in sequence 1-2-3; No alternation will occur while in this position. Lock 2 — Locks in sequence 2-3-1; No alternation will occur while in this position. Lock 3 — Locks in sequence 3-1-2; No alternation will occur while in this position.
In the event of a power failure, the alternating relay will return to its quiescent state and continue sequencing loads on one-at-a-time.
