Bunn FMD-5, FMD-4 service manual TANK HEATER RELAY 120V Dispensers only, SERVICE cont

SERVICE (cont.)

TANK HEATER RELAY (120V Dispensers only)

J1

J2

J4

J3

J1

J2

J4

J3

P2635

FIG. 39 TANK HEATER RELAY

Location:

The tank heater relay is located behind the lower front access cover, mounted on the left rear side of the component bracket.

Test Procedure:

1.Disconnect the dispenser from the power source.

2.Place the tank heater switch in the “OFF” (upper) position.

3.With an ohmmeter, check for continuity between normally closed (NC-5) and common (COM-3) terminals of the relay. The indication must be less than 1 ohm.

6.With an ohmmeter, check for continuity between the normally closed (NC-5) and common (COM-3) terminals of the relay.

7.Place containers below any three dispense nozzles.

8.Connect the dispenser to the power source.

9.Simultaneously initiate dispenses at each of the selected dispense stations while monitorintg con- tinuity across the referenced terminals of the tank heater relay. The indication must be open circuit.

If continuity is absent as described, the relay is func- tioning correctly.

If continuity is present, replace the relay.

Removal and Replacement:

1.Loosen the three #8-32 screws securing the com- ponent bracket to the dispenser housing base.

2.Pull component bracket out the front of the dis-

penser far enough so the tank heater relay can be disconnected from the main wiring harness.

3Disconnect the tank heater relay from the main wiring harness.

4.Remove the two #8-32 screws securing the tank heater relay to the rear of the component bracket.

5.Remove and discard the tank heater relay.

6.Install new tank heater relay on the rear of the component bracket and secure with two #8-32 screws.

7.Connect the tank heater relay to the main wiring harness (see Fig. 40).

8.Place the component bracket into position and tighten the three #8-32 screws.

If continuity is present as described, proceed to step 4. If continuity is not present as described, replace the relay.

4.With an ohmmeter, check the resistance across the coil terminals (1 & 2) of the relay. The indica- tion must be approximately 4,000 ohms (4kΩ).

If the resistance measures as described, proceed to step 5.

BRN/BLK from Main Harness

BLK from Main Harness

BLK from Main Harness

WHI from Main Harness

No Connection

If the resistance does not measure as described, replace the relay.

5.Disconnect the wires from the normally closed (NC-5) and common (COM-3) terminals of the relay.

P2639

FIG. 40 TANK HEATER RELAY TERMINALS

40 35135 012103