Manuals / Bunn / Kitchen Appliance / Coffeemaker

Bunn U3A service manual SERVICE cont MASTER ON/OFF SWITCH Late Models, Master On/Off Switch Loc

Models: U3A U3

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SERVICE (cont.)

SERVICE (cont.)

MASTER ON/OFF SWITCH (Late Models)

P1752.55

FIG. 36 MASTER ON/OFF SWITCH LOC.

Location:

The Master ON/OFF switch is located in the top hous- ing at the rear, FIG. 36.

Test Procedure:

1.Disconnect the brewer from the power source and remove the wires from all terminals of the Master ON/OFF switch.

2.Check for continuity across the two terminals on the switch at L1 BLK and BLK to Main Harness when it is held in the lower position, Fig. 32. Check for continuity across the two terminals on the switch at L2 RED and RED to Main Harness when it is held in the lower position.

Continuity must not be present across these terminals in the upper position.

If continuity is present as described, reconnect the wires, the switch is operating properly.

If continuity is not present as described, replace the switch.

Removal and Replacement:

1.Remove all wires from the switch terminals.

2.Remove the two screws from the outside of the base and gently push the switch through the opening.

3.Locate the new switch into the opening and se- cure with screws removed in step 2.

4.Refer to FIG. 37 when reconnecting the wires.

Incoming Power Supply
L1	- BLK
L2	- RED
Main Wiring harness
BLK
RED
	P3955
FIG. 37 MASTER ON/OFF SWITCH WIRING

Page 36	10060	011708

Image 36

Bunn U3A service manual SERVICE cont MASTER ON/OFF SWITCH Late Models, Master On/Off Switch Loc

Contents

OPERATING & SERVICE MANUAL U3 U3ABUNN-O-MATIC CORPORATION BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTY PageINTRODUCTION USER NOTICESATTENTION TURN OFF WHEN UNATTENDED Very Hot Water Use With CareELECTRICAL INSTALLATION INSTRUCTIONS ELECTRICAL REQUIREMENTSINITIAL SETUP CE REQUIREMENTSPLUMBING REQUIREMENTS INITIAL SETUP cont ADJUSTING BREW VOLUMESVolumes CLEANING COFFEE BREWINGFILTER HOLDER TROUBLESHOOTING PROBLEMPROBABLE CAUSE TROUBLESHOOTING cont PROBLEM PROBABLE CAUSEREMEDY TROUBLESHOOTING cont PROBLEMPROBABLE CAUSE TROUBLESHOOTING cont PROBLEM Refer to Service - Contactor for testing procedures. See pagePROBABLE CAUSE REMEDYTROUBLESHOOTING cont PROBLEM Funnels overflow cont Coffee reservoir overflowsPROBABLE CAUSE REMEDYSERVICE COMPONENT ACCESSContents SERVICE cont Wire Models and 440V Four Wire ModelsCONTACTOR SERVICE cont2A. 120/208V, 120/240V, 380V THREE WIRE MODELS SERVICE cont CONTACTOR cont BLK to Right TankTank Heater BLK Thermal Fuse to Right Tank Heater BLK to Terminal Block L1SERVICE cont CONTROL THERMOSTAT Disconnect the wires from the control thermoInstall 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 SERVICE cont LIQUID LEVEL BOARD AND LEVEL PROBE VoltageSERVICE cont LIQUID LEVEL BOARD AND LEVEL PROBE 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 SERVICE cont RELAY BREWERS W/BREW LOCKOUT BLU fromSERVICE 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 SERVICE cont START SWITCH BREW FIG. 24 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 SERVICE cont TIMER Early Modelscont To Three Pin FemaleSERVICE cont DIGITAL TIMER Late Models SERVICE cont DIGITAL TIMER Late Models NOTE All volume settings must be done with the sprayhead installedNOTE 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 SERVICE cont MASTER ON/OFF SWITCH Late Models FIG. 36 MASTER ON/OFF SWITCH LOC120/208 VOLTS AC 120/240 VOLTS AC 3 WIRE + GND SINGLE PHASE MAIN ON/OFF SWITCH Late Models onlyPage 10060Page 10060080900 SCHEMATIC WIRING DIAGRAM U3A & U38A BREWERS PRIOR TO U300004095 Page10060 080900SCHEMATIC WIRING DIAGRAM U3A - CE BREWERS S/N U300004095 - UP Page10060 080900SCHEMATIC WIRING DIAGRAM U3833 Page10060 080900SCHEMATIC WIRING DIGRAM U3833 Page10060 080900