Bunn OT Installation & Operating Manual Download

Page: 13 / 35

Page 13

FIG. 1 ACCESS PANELS

SERVICE

This section provides procedures for testing and replacing various major components used in this brewer

should service become necessary. Refer to Troubleshooting for assistance in determining the cause of any

problem.

Component Access

WARNING - Disconnect the brewer from the power

source before the removal of any panel or the replace-

ment of any component.

The brew timer, and control thermostat are lo-

cated behind the front panel, FIG. 1 located beneath

the brew funnel, attached with four #8-32 slotted-head

screws.

The base warmer(s), switch(es), indicator lamp,

start switch, tank “keep warm” heater, terminal block,

and solenoid valve, are located in the base. Access

is gained by removing the rear panel, FIG. 1 attached

with two #8-32 slotted-head screws

The limit thermostat, and tank heater are located

on the tank lid. Access is gained by removing the

top lid, FIG. 1 attached with three #8-32 slotted head

screws. On the model OT, the upper warmer, switch,

and associated indicator lamp are located on this

removable top lid.

WARNING - Inspection, testing, and repair of electri-

cal equipment should be performed only by qualified

service personnel. The brewer should be disconnected

from the power source when servicing, except when

electrical tests are required and the test procedure

specifically states to connect the brewer to the power

source.

P1687

P1688

32440 010308

Contents

Brew Timer (Early Models).................................... 13

Digital Timer (Late Models) ................................... 14

Control Thermostat ............................................... 16

Warmer(s)

OT:

Brew Station & Upper ..............................................

RT:

Left Rear, Left Front, Brew Station, Right Rear

& Right Front .............................................................

Warmer Switch(es)

OT:

On/Off Brew Station & Upper ...................................

RT:

On/Off Brew Station ..................................................

RT:

Left Rear, Left Front, Right Rear

& Right Front Rotary ..................................................

Indicator Lamp(s) ................................................. 20

Limit Thermostat ................................................... 21

Solenoid Valve ...................................................... 22

Start Switch .......................................................... 23

Tank Heater ........................................................... 24

Thermal Cut-off ................................................... 25

Master ON/OFF Switch .......................................... 26

Wiring Schematics .............................................. 27

Summary of Contents for OT

Page 1: ...he latest revision of the Operating Manual or to view the Illustrated Parts Catalog Programming Manual or Service Manual please visit the Bunn O Matic website at www bunn com This is absolutely FREE and the quickest way to obtain the latest catalog and manual updates For Technical Service contact Bunn O Matic Corporation at 1 800 286 6070 32440 0000D 05 12 1999 BUNN O MATIC CORPORATION ...

Page 2: ...ions to this warranty or to make additional warranties that are binding on BUNN Accordingly statements by such individuals whether oral or written do not constitute warranties and should not be relied upon If BUNN determines in its sole discretion that the equipment does not conform to the warranty BUNN at its exclusive op tion while the equipment is under warranty shall either 1 provide at no cha...

Page 3: ...re turning on thermostat or connecting appliance to power source Use only on a properly protected circuit capable of the rated load Electrically ground the chassis Follow national local electrical codes Do not use near combustibles FAILURE TO COMPLY RISKS EQUIPMENT DAMAGE FIRE OR SHOCK HAZARD READ THE ENTIRE OPERATING MANUAL BEFORE BUYING OR USING THIS PRODUCT THIS APPLIANCE IS HEATED WHENEVER CON...

Page 4: ... coding of each conductor at the electrical source 3 Remove the front panel beneath the sprayhead and rotate the control thermostat knob fully counterclockwise to the OFF position and re place the panel 4 Remove the rear panel feed the cord through the strain relief and connect it to the terminal block 5 Connect the brewer to the power source and verify the voltage at the terminal block before pro...

Page 5: ...hape of the hole made in the supply line by this type of device may restrict water flow P1709 As directed in the International Plumbing Code of the International Code Council and the Food Code Manual of the Food and Drug Administration FDA this equipment must be installed with adequate backflow pre vention to comply with federal state and local codes For models installed outside the U S A you must...

Page 6: ...panel 9 Rotate the control thermostat knob fully clock wise to the ON position and replace the front panel 10 Connect the brewer to the power source and wait approximately twenty minutes for the water in the tank to heat to the proper temperature Some water will drip from the funnel during this time this is due to expansion and should not occur thereafter 11 Place an empty decanter under the funne...

Page 7: ...or modifying batch sizes check that the brewer is connected to water supply the tank is properly filled and a funnel and server are in place 1 Modifying batch sizes To modify a batch volume first check that the SET LOCK switch is in the SET posi tion on the circuit board To increase a batch size Press and hold the START or BREW switch until three clicks are heard Release the switch Failure to rele...

Page 8: ...panel located beneath the brew funnel 2 Adjust the needle valve as required to increase or decrease the pressure of the hot water flowing from the faucet Turn the propeller on the valve in a counterclockwise direction to increase the flow and in a clockwise direction to decrease the flow 3 Reconnect the brewer to the power source and allow the water in the tank to heat to the proper temperature be...

Page 9: ...s have 120 volt ac voltage on their terminals Shorting of terminals or the application of external voltages may result in equipment failure Intermittent operation of electronic equipment is unlikely Component failure will normally be permanent If an intermittent condition is encountered the cause will likely be a switch contact or a loose connection at a terminal or crimp Solenoid removal requires...

Page 10: ...Station Warmer Switch for testing procedures See page 18 Refer to Service Start Switch for testing procedures See page 23 Refer to Service Timer for testing procedures See page 13 14 Refer to Service Solenoid Valve for testing procedures See page 22 Refer to Service Solenoid Valve for testing procedures See page 22 Refer to Service Timer for testing procedures See page 13 14 Refer to Service Limit...

Page 11: ...k assembly for ex cessive lime deposits Delime as required A Direction of flow arrow must be pointing away from the solenoid B Remove the control and check for obstructions Clear or replace Check the operating water pressure to the brewer It must be between 20 and 90 psi 138 and 620 kPa Water should flow freely from the sprayhead for approximately twenty seconds after the brew solenoid has shut of...

Page 12: ...r should be centered in the funnel and the bed of coffee leveled by gentle shaking Place a funnel over an empty de canter on the warmer beneath the sprayhead Place the On Off brew station warmer switch in the upper position press the start switch and check the water temperature immediately below the sprayhead with an accurate thermometer The reading should not be less than 195 F Adjust the control...

Page 13: ...on the tank lid Access is gained by removing the top lid FIG 1 attached with three 8 32 slotted head screws On the model OT the upper warmer switch and associated indicator lamp are located on this removable top lid WARNING Inspection testing and repair of electri cal equipment should be performed only by qualified service personnel The brewer should be disconnected from the power source when serv...

Page 14: ...ribed in step 2 until the start switch is released 5 Disconnect the brewer from the power source If voltage is present as described reconnect the polar ized three pin connectors and proceed to 6 If voltage is not present as described refer to the Wir ing Diagrams and check the brewer wiring harness 6 Disconnect the in line connectors on the black and white wires from the timer to the solenoid 7 Ch...

Page 15: ... to the power source The indication must be a 120 volts ac for two wire 120 volt models b 200 or 240 volts ac for two wire 200 or 240 volt models and three wire 120 240 volt models c 100 volts ac for two wire 100 volt models If continuity is present as described reconnect the wires and proceed to 7 If continuity is not present as described refer to the Wiring Diagrams and check the brewer wiring h...

Page 16: ...h until three clicks are heard Release the switch Failure to release the switch within two seconds after the third click causes the volume setting to be aborted and previous volume setting will remain in memory Al low the brew cycle to finish in order to verify that the desired volume has been achieved 2 Setting brew volumes To set a brew volume first check that the SET LOCK switch is in the SET p...

Page 17: ...e as described in step 2 Voltage must not be indicated across these terminals when the thermostat is turned OFF fully counterclockwise 5 Disconnect the brewer from the power source If voltage is present as described the control thermo stat is operating properly If voltage is not present as described replace the control thermostat Removal and Replacement 1 Remove both wires from the control thermos...

Page 18: ...to the splice or indicator lamp using the chart below If continuity is present as described proceed to 6 If continuity is not present as described refer to the Wiring Diagrams and check the brewer wiring har ness 6 Check for continuity across the two terminals on the warmer If continuity is present as described the warmer is operating properly If continuity is not present as described replace the ...

Page 19: ... 3 Refer to FIG 13 when reconnecting the wires 4 Push the new switch firmly into the opening Location These switches are located beneath and to the left of their associated warmers as viewed from the front FIG s 11 and 12 Test Procedure 1 Locate the switch terminal with black wires that do not go to the nearby indicator lamp 2 Check the voltage across this terminal and the terminal on the indicato...

Page 20: ... 3 Check the voltage across terminal 1 and the white or red wire on the terminal block with a voltmeter when the switch is in the ON position Connect the brewer to the power source The indication must be as described in step 1 Voltage must not be present across these terminals in the OFF positions 4 Disconnect the brewer from the power source If voltage is present as described the switch is operat...

Page 21: ...the switch to the indicator lamp 2 Check continuity of the white or red wire from the indicator lamp to the terminal block If continuity is present proceed to 3 If continuity is not present refer to Wiring Diagrams and check brewer wiring harness 3 Check for voltage across the indicator lamp ter minals Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 vo...

Page 22: ... thermostat is located on the tank lid between the tank heater terminals FIG 19 Test Procedure 1 Disconnect the brewer from the power source 2 Check voltage across the black wire from the limit thermostat and the white or red wire on the tank heater terminal Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models b 200 or 240 volts ac for two wire ...

Page 23: ...ole noid valve to the bracket 7 Lift out the solenoid valve 8 Securely install the new solenoid valve to the bracket Check the direction of flow arrow on the valve It must be pointing toward the flow control 9 Securely fasten the water lines to and from the solenoid valve 10 Refer to FIG 22 when reconnecting the wires Location The solenoid valve is located below and to the left of the tank as view...

Page 24: ... 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 Compress the clips inside the housing and gently push the switch through the o...

Page 25: ... and spray head 15 Reinstall the thermostat into the tank lid 16 Refer to FIG 27 when reconnecting the wires Location The tank heater is located on the tank lid FIG 26 Test Procedure 1 Check the voltage across the black and white or red wires on the tank heater with a voltmeter when the control thermostat is turned ON fully clockwise Connect the brewer to the power source The indication must be a ...

Page 26: ...inuity across the thermal cut off terminals using an ohmmeter If continuity is present the thermal cut off is operat ing properly If continuity is not present as described replace the thermal cut off Removal and Replacement 1 Disconnect the thermal cut off from the tank heater terminal and the wiring harness 2 Remove thermal cut off and discard 3 Connect new thermal cut off to the tank heater term...

Page 27: ...cross 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 ter...

Page 28: ...SINGLE PHASE 60 HZ BLK UPPER WARMER BLK BLK WHI P3 WHI P2 WHI KEEP WARM HEATER BLK BLU LIMIT THERMOSTAT SW THERMOSTAT BLK GREEN TANK HEATER WHI WHI BLK FAUCET OPTION ONLY THERMAL CUT OFF SOL T5 T1 T2 T4 T3 P1 P2 P3 ARE PINS OF A POLARIZED THREE PIN CONNECTOR WHI OT20 RED OT35 BLK OT20 35 L1 L2 BLK BLK OT15 only WHI OT35 only WHI OT20 only WHI OT20 only N MAIN ON OFF SWITCH Late OT20 35 Models only...

Page 29: ...OF A POLARIZED THREE PIN CONNECTOR 10280 0000D 7 00 1988 BUNN O MATIC CORPORATION 120 240 VOLTS AC 3 WIRE SINGLE PHASE RED TANK HEATER BLK UPPER WARMER 130W BLK WHI P3 WHI P2 WHI TAN SELECTOR CONTROL BOARD BLK PNK TAN GRY PNK TAN GRY GRINDER INTERFACE CONNECTORS WHI 2 3 F 1 3 GRN YEL RED 3500W KEEP WARM HEATER 50W WHI WHI SW THERMOSTAT WHI GRN WHI BLU BREW TIMER SOL T5 T1 T2 T4 T3 32440 070700 ...

Page 30: ...ING DIAGRAM OTA BLK L2 BLK BLK P1 P2 P3 ARE PINS OF A POLARIZED THREE PIN CONNECTOR 10282 0000B 7 00 1988 BUNN O MATIC CORPORATION 240 VOLTS AC 2 WIRE SINGLE PHASE 50 60 HZ RED BLK TANK HEATER BLK UPPER WARMER BLK P3 P2 RED BLK RED BLK RED BLK RED BLK RED BLK BLK RED BLK WHI GRN WHI BLU WHI BREW TIMER SOL T5 T1 T2 T4 T3 32440 070700 ...

Page 31: ...PIN CONNECTOR 100 VOLTS AC 2 WIRE SINGLE PHASE 50 60 HZ BLK UPPER WARMER BLK P3 P2 RED RED RED RED RED BLK RED WHI BLK BLU LIMIT THERMOSTAT L1 BLK GRN YEL N RED TANK HEATER BLU READY INDICATOR BLK SW THERMOSTAT BLK RED K1 N O K1 N O RED BLK 10635 0000B 7 00 1991 Bunn O Matic Corporation K1 WHI GRN WHI BLU BREW TIMER SOL T5 T1 T2 T4 T3 32440 070700 ...

Page 32: ...T35B BLK L2 BLK BLK P1 P2 P3 ARE PINS OF A POLARIZED THREE PIN CONNECTOR 200 VOLTS AC 2 WIRE SINGLE PHASE 50 60 HZ RED TANK HEATER BLK UPPER WARMER BLK P3 P2 RED RED RED RED RED BLK RED BLU READY INDICATOR BLK SW THERMOSTAT 10637 0000B 7 00 1991 Bunn O Matic Corporation WHI GRN WHI BLU WHI BREW TIMER SOL T5 T1 T2 T4 T3 32440 070700 ...

Page 33: ...N OFF ON L1 1 OFF ON OFF ON L1 1 BLU BLU BLK WHI BLK P1 P3 P2 BLK BLK P1 P2 P3 ARE PINS OF A POLARIZED THREE PIN CONNECTOR BLU LIMIT THERMOSTAT SW THERMOSTAT TANK HEATER N BLK BLK L1 BLK GREEN L2 RED WHI WHI BLK FAUCET OPTION ONLY THERMAL CUT OFF WHI BLK BLK RIGHT REAR WARMER OFF ON OFF ON L1 1 WHI BLK WHI RED 4 3 2 1 PIN GRY L E D INDICATOR TIMER OPTIONAL FLASHING INDICATOR SYSTEM WHI GRN WHI BLU...

Page 34: ...RTA BLK L2 RED BLK BLK P1 P2 P3 ARE PINS OF A POLARIZED THREE PIN CONNECTOR BLK BLK BLK BLK BLK BLK LEFT FRONT WARMER RIGHT FRONT WARMER LEFT REAR WARMER 240 VOLTS AC 2 WIRE SINGLE PHASE 50 60 HZ OFF ON OFF ON L1 1 OFF ON OFF ON L1 1 OFF ON OFF ON L1 1 RED RED RED RED RED RED BLK BLK RIGHT REAR WARMER OFF ON OFF ON L1 1 RED WHI GRN WHI BLU WHI BREW TIMER SOL T5 T1 T2 T4 T3 32440 070700 ...

Page 35: ... RT BLK N WHI BLK BLK P1 P2 P3 ARE PINS OF A POLARIZED THREE PIN CONNECTOR BLK BLK BLK BLK BLK BLK LEFT FRONT WARMER RIGHT FRONT WARMER LEFT REAR WARMER OFF ON OFF ON L1 1 OFF ON OFF ON L1 1 OFF ON OFF ON L1 1 WHI WHI WHI WHI WHI WHI BLK BLK RIGHT REAR WARMER OFF ON OFF ON L1 1 WHI 120 VOLTS AC 2 WIRE SINGLE PHASE 50 60 HZ WHI GRN WHI BLU WHI BREW TIMER SOL T5 T1 T2 T4 T3 32440 070700 ...

Search results

Summary of Contents for OT

Reviews:

Related manuals for OT

Brands by name

Popular brands

Bunn OT, Installation & Operating Manual

Search results

Summary of Contents for OT

Reviews:

Related manuals for OT

Brands by name

Popular brands