Bunn ULTRA-1 manual SERVICE cont TORQUE SENSOR CIRCUIT BOARD, Do Not Turn On Augers

SERVICE (cont.)

TORQUE SENSOR CIRCUIT BOARD

ULTRA-2 shown

FIG. 63 TORQUE SENSOR CIRCUIT BOARD P1341

Location:

The torque sensor circuit board is located on the rear of the cooling drum mount just left of center.

Test Procedures:

1.Place black meter lead at J1-3 (common) and red lead at J1-1 (signal). Set meter to 10 - 20volts DC scale. Turn on power switch.

DO NOT TURN ON AUGERS!

2.Using a strip of paper, momentarily block the light path between red LED and white phototransistor. If the meter displays 5vdc when blocked and 0v when unblocked, then the Torque Sensor is good. If there is no 5vdc reading, verify that both red and white sensors are clean.

3.If there is still no 5vdc reading when blocked, place the red meter lead at J1-2 and verify that there is 4.5vdc supplied to Torque Sensor. If there is no 5vdc supplied, check wiring between control board and Torque Sensor. If wiring is ok, then replace the main control board.

1.Ultra-2 Left Signal (WHI/GRY)

1.Ultra-2 Right Signal (WHI/GRN)

1.Ultra-1 Signal (WHI/GRY)

2. (+) 5vdc (BLU)

3. (-) common (WHI/BLK)

1

J1

L.E.D.

PHOTOTRANSISTOR

FIG. 64 TORQUE SENSOR CIRCUIT

BOARD TERMINALS

Removal and Replacement:

1.Remove the two #8-32 locking screws securing the auger motor cover to the cooling drum mount.

2.Remove the cover and set aside for reassembly.

3.Remove the #8 locking screw on the lower right side of the auger motor mounting bracket securing the auger motor run capacitor. Set capacitor aside with wires attached.

4.Disconnect the auger motor plug from the connector on the main wiring harness.

5.Remove the three remaining #8 locking screws securing the auger motor mounting bracket to cooling drum mounting bracket.

6.Remove motor with mounting bracket, split pin/

torsion spring bearings as an assembly and set aside for reassembly.

NOTE: When removing or installing the motor be sure the split pin in the motor shaft is turned to a position that will clear the torque sensor circuit board.

7.Disconnect the plug from the dispenser main wiring harness to the torque sensor circuit board.

8.Remove the #8-32 locking screw and washer secur- ing torque sensor circuit board to the cooling drum mount.

9.Remove torque sensor circuit board and discard.

10.Install new torque sensor circuit board in the slot in the rear of the cooling drum mount and secure with a #8-32 locking screw and washer.

11.Refer to Fig. 42 and reconnect the wires.

12.Reinstall motor with mounting bracket, drip tray, split pin and torsion spring bearings using three #8 locking screws onto the cooling drum bracket.

13.Install the auger motor capacitor on the lower right side of the auger mounting bracket using the remaining #8 locking screw.

14.Connect the auger motor terminal to the terminal on the main wiring harness.

15.Refer to Fig. 64 when reconnecting the wires.

16.Position the auger motor cover on the cooling drum mount and secure with two #8-32 locking screws.

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