Manuals / Bunn / Kitchen Appliance / Coffeemaker

Bunn U3A service manual SERVICE cont, LIQUID LEVEL BOARD AND LEVEL PROBE cont

Models: U3A U3

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LIQUID LEVEL BOARD AND LEVEL PROBE (cont.)

SERVICE (cont.)

LIQUID LEVEL BOARD AND LEVEL PROBE (cont.)

9.Reconnect the pink wire to terminal 4.

10.Remove the two #8-32 screws securing the level probe to the component bracket.

11.Gently pull the probe out of the component bracket

and inspect for corrosion. Replace if necessary.

12 Place the probe so that neither end is in contact with any metal surface of the brewer.

13.Connect the brewer to the power source. Check the voltage across terminals 1 and 3, refer to chart below. There is an approximate delay of five seconds for output to stabilize.

Model	Voltage -	Voltage -
	Jumper	Jumper
	Not Touching	Touching
	Frame	Frame
120/208V &	120V	0
120/240V - 3
wire w/ground
single phase
230V - 2 wire	230V	0
w/ground
single phase
208V or 240V -	208V or	0
2 wire wground	240V	0
single phase
280V or 440V -	220V or	0
4 wire w/ground	254V	0
3 phase
380V - 3 wire	120V	0
w/ground 3

phase w/ stepdown trans- former

14. Disconnect the brewer from the power source.

If voltage is present as described, reinstall the level probe, the liquid level board and level probe are op- erating properly.

If voltage is not present as described, check the pink wire on the level probe from liquid level board terminal 4.

Removal and Replacement:

1.Remove all wires from the liquid level board.

2.Remove the #10-32 screw and flat washer securing the protective shield to the component bracket.

3.Remove the #10-32 screw and internal tooth lockwasher securing the liquid level board to the component bracket.

4.Remove liquid level board and discard.

5.Install new liquid level board on component bracket and secure with a #10-32 screw and internal tooth lockwasher.

6.Install protective shield and secure with #10-32 screw and flat washer.

7.Refer to Fig. 13 and reconnect the wires.

T1 BLU to Solenoid Valve

T2 BLK to ON/OFF Switch (All models except 230V-CE models)

T3 WHI to Main Harness (120/208V, 120/240V, four wire 380V and 440V models)

T3 WHI to Transformer

(380V three wire models)

T3 RED to Main Harness (208V, 240V single phase and three phase models) T3 BLK to Main Harness (230V two wire models)

T4 PIN to Level Probe

P1733

FIG.13 LIQUID LEVEL BOARD TERMINALS

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Bunn U3A service manual SERVICE cont, LIQUID LEVEL BOARD AND LEVEL PROBE cont

Contents

OPERATING & SERVICE MANUAL U3 U3ABUNN-O-MATIC CORPORATION Page BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTYUSER NOTICES INTRODUCTIONATTENTION TURN OFF WHEN UNATTENDED Very Hot Water Use With CareELECTRICAL REQUIREMENTS ELECTRICAL INSTALLATION INSTRUCTIONSINITIAL SETUP CE REQUIREMENTSPLUMBING REQUIREMENTS INITIAL SETUP cont ADJUSTING BREW VOLUMESVolumes CLEANING COFFEE BREWINGFILTER HOLDER TROUBLESHOOTING PROBLEMPROBABLE CAUSE PROBABLE CAUSE TROUBLESHOOTING cont PROBLEMREMEDY TROUBLESHOOTING cont PROBLEMPROBABLE CAUSE Refer to Service - Contactor for testing procedures. See page TROUBLESHOOTING cont PROBLEMPROBABLE CAUSE REMEDYFunnels overflow cont Coffee reservoir overflows TROUBLESHOOTING cont PROBLEMPROBABLE CAUSE REMEDYSERVICE COMPONENT ACCESSContents Wire Models and 440V Four Wire Models SERVICE contCONTACTOR SERVICE cont2A. 120/208V, 120/240V, 380V THREE WIRE MODELS BLK to Right Tank SERVICE cont CONTACTOR contTank Heater BLK Thermal Fuse to Right Tank Heater BLK to Terminal Block L1Disconnect the wires from the control thermo SERVICE cont CONTROL THERMOSTATInstall thermostat and mounting bracket on the FIG. 6 CONTROL THERMOSTATSERVICE cont FIG.8 FUSE AND FUSE HILDERFIG. 9 FUSE HOLDER TERMINALS SERVICE cont LIMIT THERMOSTAT Disconnect the brewer from the power sourceWith an ohmmeter, check for continuity across Voltage SERVICE cont LIQUID LEVEL BOARD AND LEVEL PROBELIQUID LEVEL BOARD AND LEVEL PROBE cont SERVICE contSERVICE cont ON/OFF SWITCH RED to Start Switch, Brew Timer & Liquid Level BoardFIG. 15 ON/OFF SWITCH TERMINALS SERVICE cont PUMP ASSEMBLY SERVICE cont RELAY BREWERS W/BREW LOCKOUT BLU from SERVICE cont RELAY BREWERS W/BREW LOCKOUTSERVICE cont SELECTOR SWITCH HALF BATCH OPTION SOLENOID SERVICE cont2. A For 120/208 volt and 120/240 volt three wire, single phase models, 380 volt three wire, three phase models and 380 volt, 440 volt four wire, three phase models, disconnect the black wire from the liquid level board #2 and the white wire on the solenoid. With a voltmeter, check the voltage across the black and the white wire. Connect the brewer to the power source. The indication must be SERVICE cont SOLENOID FIG. 24 START SWITCH BREW SERVICE cont START SWITCH BREWSERVICE cont TANK HEATERS LEFTFIG. 27 TANK HEATER TERMINALS SERVICE cont THERMAL FUSES 230V-CE MODELS ONLY TIMER Early ModelsFIG. 28 THERMAL FUSES To Three Pin Female SERVICE cont TIMER Early ModelscontSERVICE cont DIGITAL TIMER Late Models NOTE All volume settings must be done with the sprayhead installed SERVICE cont DIGITAL TIMER Late ModelsNOTE Half-Batch and full batch settings must each be set separately FIG. 33 DIGITAL TIMER TERMINALSSERVICE cont TRANSFORMER 380V THREE WIRE MODELS ONLYFIG. 35 TRANSFORMER TERMINALS FIG. 36 MASTER ON/OFF SWITCH LOC SERVICE cont MASTER ON/OFF SWITCH Late ModelsMAIN ON/OFF SWITCH Late Models only 120/208 VOLTS AC 120/240 VOLTS AC 3 WIRE + GND SINGLE PHASEPage 10060Page 10060080900 Page SCHEMATIC WIRING DIAGRAM U3A & U38A BREWERS PRIOR TO U30000409510060 080900Page SCHEMATIC WIRING DIAGRAM U3A - CE BREWERS S/N U300004095 - UP10060 080900Page SCHEMATIC WIRING DIAGRAM U383310060 080900Page SCHEMATIC WIRING DIGRAM U383310060 080900