168-7823 Time Delay Relay In The Engine Supervisory System (ESS) Caterpillar

Reference: ENGINE NEWS, SEPTEMBER 2000, PAGE 5, "New Time Delay Relay Used In The Engine Supervisory System (ESS)"

Problem:

Some 168-7823 Time Delay Relays may have an incorrect supplier model number.

Solution:

See the illustration. If the supplier model number (D) is 3PR1505-1BW30, the time delay relay is correct. Some 168-7823 Time Delay Relays have a supplier model number (D) that is 3PR1505-1AQ30. This is not correct. If you have a time delay relay with an incorrect model number, that time delay relay can still be used if it is installed differently then a time delay relay with the correct model number.

When connecting a 3PR1505-1AQ30 time delay relay to the ESS panel, there are two changes that must be made to the wiring:

1. Connect the wire that normally goes to the A1 terminal of the time delay relay to the A3 terminal of the time delay relay.

2. Connect the wire that normally goes to the B1 terminal of the time delay relay to the B3 terminal of the time delay relay.

All of the other connections are the same as shown in the wiring diagram.

For a time delay of approximately 13 seconds, set up the Time Delay Relay as follows:

* Turn potentiometer (A) to a value of 40%.

* Turn rotary switch (B) until the value 30s is in the opening (B1).

* Turn rotary switch (C) until the value B is in the opening (C1). Do NOT set a value of "B." (B followed by a dot) in the opening (C1).

This Is A View Of A 168-7823 Time Delay Relay With An Incorrect Supplier Model Number (D). The Correct Supplier Model Number (D) is 3RP1505-1BW30.

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