Programmable Relay Control Module (PRCM) Caterpillar

The maximum length of the CAT data link cable that connects the PRCM to the engine ECM is 30.5 m (100 ft). If the length of the cable exceeds 30.5 m (100 ft), a Customer Communication Module (CCM) is required. The customer communication module is used in order to increase the signal of the CAT data link. Connect the + battery on the customer communication module to the + battery post on the rear of the PRCM. Connect the negative battery on the customer communication module to the negative battery post on the rear of the PRCM. Connect the CAT data link to the PRCM. Connect the CAT data link + to contact 19 and connect the CAT data link - to contact 20.

Note: Shielded twisted pair cable is required for the CAT data link. Use 123-2376 Electrical Cable .

• The operating voltage range is from 15 to 45 DCV. The relay driver module (RDM) is powered from a battery system of 24 DCV or a battery system of 32 DCV.

• The case of the PRCM is electrically isolated from the internal circuitry.

• The PRCM is protected against reverse battery polarity.

• The input/output circuitry is protected. The circuitry is protected from a short to the positive battery source and ground. Terminals 2, 13, and 14 on the RDM are NOT fused. These terminals are NOT protected from a short circuit to the positive battery source or ground.

• The PRCM is capable of operating with an earth ground and the PRCM is capable of operating without an earth ground.

• The PRCM must share a common ground with the optional Relay Driver Module (RDM) and the relay boards.