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Page 18

T1 BLU to Solenoid Valve

T2 RED to ON/OFF Switch

T3 BLK  to Main Harness

T4 PNK to Level Probe

FIG.11 LIQUID LEVEL BOARD TERMINALS

P1733.50

SERVICE (cont.)

LIQUID LEVEL BOARD AND LEVEL PROBE (cont.)

touching the frame. Repeat these several times.
Keep in mind there is  an approximate five second
delay for output to stabilize.

8. Disconnect the brewer from the power source and

remove the jumper wire from T4.

If voltage is present as described, liquid level board is
operating properly, proceed to #9.
If voltage is not present as described, replace the liquid
level board.

9. Reconnect the pink wire to T4.
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 and

simulate the "FULL" and "NEED WATER" condi-
tions by touching the end of the probe to any metal
surace of the brewer. Measure the voltage be-
tween T1 and T3 on the liquid level board.  The
voltage should be 0 volts with the probe touching
the frame and 230 volts ac not touching the frame.
Keep in mind there is an approximate delay of five
seconds for output to stabilize.

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
operating properly.
If voltage is not present as described, check the pink
wire on the level probe from liquid level board T4.

Removal and Replacement:
1. Remove all wires from the liquid level board.
2. Remove the #10-32 screw and flat washer secur-

ing 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. 11 and reconnect the wires.

10060.3  070102

Summary of Contents for U3A

Page 1: ...NG SERVICE MANUAL BUNN O MATIC CORPORATION POST OFFICE BOX 3227 SPRINGFIELD ILLINOIS 62708 3227 PHONE 217 529 6601 FAX 217 529 6644 www bunnomatic com U3A BUNN 10060 0003A 07 02 2002 Bunn O Matic Corp...

Page 2: ...ted by BUNN shipping the defective equipment prepaid to an authorized BUNN service location and 3 receiving prior authorization from BUNN that the defective equipment is under warranty THE FOREGOING W...

Page 3: ...ewer and in this manual They were written for your protection All notices on the brewer are to be kept in good condition Replace any unreadable or damaged labels 00878 0000 12593 0000 03408 0000 03409...

Page 4: ...cold water system with operating pressure between 20 and 90 psi 138 and 620 kPa from a 1 2 or larger supply line A shut off valve should be installed in the line before the brewer Install a regulator...

Page 5: ...nect the brewer to the power source and wait for the water in the tank to heat to the proper temperature This will take approximately 1 2 hours depending on the incoming water temperature Some water w...

Page 6: ...the water stream from the swing arm Release the switch Failure to release the switch within two seconds after the third break in the water stream causes the volume setting to be aborted and previous v...

Page 7: ...damp cloth 2 Drain both coffee reservoirs by opening coffee faucets When empty close faucets 3 Cycle two or three inches of water into each coffee reservoir adding a bucket of crushed ice to obtain a...

Page 8: ...airofelectricalequipmentshouldbeperformedonlybyqualifiedservicepersonnel All electronic components have 230 volt ac and low voltage dc potential on their terminals Shorting of terminals or the applica...

Page 9: ...ng procedures See page 20 Refer to Service Solenoid Valve for testing procedures See page 22 A Direction of flow arrow must be pointing towards brewer B Remove the strainer and check for obstructions...

Page 10: ...r must be level and installed on a sturdy structure Refer to Service Solenoid Valve for testing procedures See page 22 Refer to Service Liquid Level Board for testing procedures See page 17 Refer to S...

Page 11: ...rtoService Timerfortesting procedures See page 26 or 28 Refer to Service Start Switch for testing procedures See page 23 RefertoService Timerfortesting procedures See page 26 or 28 Refer to Service So...

Page 12: ...to Service Timer for test ing procedures See page 26 or 28 Checkpumpflowratewithawatch Pumpflowrateshouldbeapproxi mately 24 ounces in 15 seconds Be sure pump assembly is free of any obstructions Plum...

Page 13: ...tthebrewerfromthepower source before the removal of any panel or the replace ment of any component All components are accessible by the removal of the swing spout front cupola cover rear cupola cover...

Page 14: ...ce If voltage is present as described proceed to 9 If voltage is not present as described refer to the wiring diagrams and check the brewer wiring harness 9 Check for continuity across the terminals o...

Page 15: ...hermostat Removal and Replacement 1 Disconnect the wires from the control thermostat 2 Remove the thermostat capillary bulb by firmly pullinguponthecapillaryatthecomponentbracket This will disengage t...

Page 16: ...178 60 RED from ON OFF Switch P2112 RED from Main Harness FUSE AND FUSE HOLDER Removal and Replacement Fuse 1 Remove the cap from the fuse holder 2 Remove fuse from the fuse holder inspect if blown di...

Page 17: ...EVEL BOARD AND LEVEL PROBE P2178 55 Location The liquid level board is located on the left rear of the component bracket The level probe is located on the right rear of the component bracket Test Proc...

Page 18: ...by touching the end of the probe to any metal surace of the brewer Measure the voltage be tween T1 and T3 on the liquid level board The voltage should be 0 volts with the probe touching the frame and...

Page 19: ...agram and check the brewer wiring harness 5 Disconnect all wires on the ON OFF switch 6 Check for continuity across the center terminal 2 andthelowerterminal 1 whentheswitchisinthe ON upper position C...

Page 20: ...pump does not run replace the pump If voltage is not present as described refer to the wiring diagram and check the brewer wiring harness Removal and Replacement Refer to Fig 15 1 Disconnect the wire...

Page 21: ...must not present when the switch is in the OPEN right full position If continuity is present as described the switch is operating properly If continuity is not present as described replace the switch...

Page 22: ...ribed reconnect the wires to the solenoid If continuity is not present as described replace the solenoid valve 7 Check the solenoid valve for coil action Connect thedispensertothepowersource Listencar...

Page 23: ...when the switch is 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 BLU to...

Page 24: ...operating properly If continuity is not present as described replace the switch Removal and Replacement NOTE Measurethedistancefromthetopoftheswitch plunger to the hood cover The same distance is nee...

Page 25: ...he brewer from the power source 2 Disconnect the wires from each tank heater 3 Check for continuity across the terminals of each tank heater If continuity is present as described tank heaters are oper...

Page 26: ...he component bracket Test Procedures 1 Disconnect the brewer from the power source 2 Disconnectthepolarized threepinconnectorfrom the brewer main harness and rotate the brew timer dial fully countercl...

Page 27: ...uired If voltage is not present as described replace the timer Removal and Replacement 1 Separate all connectors between the brewer wir ing harness and the timer 2 Disconnect the timer leads from the...

Page 28: ...scribed disconnect the brewer from the power source and replace the timer 7 With a voltmeter check the voltage across termi nals TL1 and TL4 when the ON OFF switch is in the ON position Connectthebrew...

Page 29: ...stream from the swing arm Release the switch Failure to release the switch within two seconds after the third break in the water stream causes the volume setting to be aborted and previous volume sett...

Page 30: ...Page 30 10493 0004A 07 02 2002 BUNN O MATIC CORPORATION 10060 3 070102...

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