Bunn H5E H5X SERVICE cont Electronic Controls cont, Electronic Controls Removal and Replacement

SERVICE (cont.)

Electronic Controls (cont.)

Electronic Controls Removal and Replacement

NOTE - Each electronic control assembly is calibrated to a temperature sensor probe. Both components MUST be replaced as a set.

1.Remove all wires from the electronic control as- sembly terminals.

2.Remove the two 8-32 screws holding the electronic control assembly to the component bracket.

3.Disconnect the temperature sensor, overflow tube temperature sensor, and indicator wires from the left side of the electronic control assembly board.

4.Remove the temperature sensor from the grom- met in the tank lid.

5.Install the new temperature sensor into the grom- met on the tank lid. Route the wires to the location of the new electronic control assembly.

6.Attach the temperature sensor, overflow tube tem- perature sensor, and indicator wires to the elec- tronic control assembly.

7.Fasten the new electronic control assembly to its bracket.

BLU to Triac Assy

WHI/BRN to Tank Heater Switch

TAN to Triac Assy

PNK to Liquid Level Probe

WHI or RED to Terminal Block

BLK to Overflow Safety Switch

GRN to Chassis Ground

WHI/BLU to Solenoid

P1774

FIG. 3 WIRING CONNECTIONS

WHI & WHI to
Temperature Sensor
PNK & GRY to
Heater Indicator
Refill Indicator
Power Indicator
Ready Indicator
GRY & GRY
toThermistor
FIG. 4 WIRING CONNECTIONS	P1774

8.Reconnect the wires.

9.Review the initial set-up procedures.

Triac Assembly Removal and Replacement

NOTE - Each triac installation requires the use of an approved silicone heat sink compound. Bunn-O-Matic recommends the use of Dow Corning 340 compound or equivalent. It can be purchased direct from Bunn-O- Matic (part # 12572.0002).

1.Place the tank heater switch on the electronic con- trol assembly in the “OFF” position.

2.Completely drain the tank.

3.Carefully set the dispenser on its face (faucet side).

4.Remove the four feet attached with four 8-32 phillips-head screws.

5.Remove the bottom panel and four feet attached with seven 8-32 slotted-head screws.

6.Remove the existing triac assembly held in place with a 10-32 hex keps nut.

7.Apply a small amount of the silicone heat sink com- pound to the copper heat sink.

8.Securely fasten the new triac assembly to the bot- tom of the tank in the same relative position as the one removed. Bunn-O-Matic recommends tighten- ing the nut to a torque setting of approximately 18 inch-pounds.

9.Route the wires up around the rear of the dispenser.

10.Reinstall the bottom panel and four feet.

11.Stand the dispenser upright.

12.Disconnect the other ends of the old triac assem- bly wires.

13.Connect the TAN and BLU wires with spade termi- nals of the new assembly to the electronic control assembly, FIG. 3.

14.Connect the BLU wire with the ring terminal to the tank heater, FIG. 13.

15.Connect the WHI/VIO wire of the new assembly to the WHI or RED terminal at the terminal block.

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