Bunn System III manual

SYSTEM III ® OPERA TING & SER VICE MANU AL BUNN-O-MA TIC CORPORA TION POST OFFICE BOX 3227 SPRINGFIELD, ILLINOIS 62708-3227 PHONE: (217) 529-6601 F AX: (217) 529-6644 27362.0000B 9/00 ©1996 Bunn-O-Matic Corporation BU N N ®[...]

Page 2 W ARRANTY Bunn-O-Matic Corp. (“Bunn”) warrants the equipment manufactured by it to be commercially free from defects in material and workmanship existing at the time of manufacture and appearing within one year from the date of installation. In addition: 1.) Bunn warrants electronic circuit and/or control boards to be commercially free f[...]

Page 3 20201.5600 00831.0000 ! WARNING HOT WATER 12364.0000 10044.0000 USER NOTICES Carefully read and follow all notices in this manual and on the equipment. The notices on this brewer should be kept in good condition. Replace any unreadable or damaged labels. 27362 092900 00656.0000 03408.0000 03409.0000[...]

Page 4 Electrical Hook-Up CAUTION – Improper electrical installation will damage electronic components. 1. An electrician must provide electrical service as specified. 2. Using a voltmeter, check the voltage and color coding of each conductor at the electrical source. 3. Remove the front panel beneath the sprayhead. Models with digital brewer con[...]

Page 5 INITIAL SET -UP CAUTION – The brewer must be disconnected from the power source throughout the initial set-up, except when specified in the instructions. 1. Remove the front panel beneath the sprayhead. Models with digital brewer control assembly: Place the tank heater toggle switch at the bottom left of the control assembly in the "O[...]

Page 6 T o decrease a batch size. Press and release the ST ART or BREW switch once for every two-second inter val to be removed from the total brew time period; then immediately press and hold down the ST ART or BREW switch until three clicks are heard. Release the switch. (Failure to release the switch within two seconds after the third click caus[...]

Page 7 TROUBLESHOOTING A troubleshooting guide is provided to suggest probable causes and remedies for the most likely problems encountered. If the problem remains after exhausting the troubleshooting steps, contact the Bunn-O-Matic Technical Service Department. • Inspection, testing, and repair of electrical equipment should be performed only by[...]

Page 8 Brew cycle will not start (cont.) Automatic refill will not operate Refer to Service - ON/OFF switch for testing procedures. See page 28 Refer to Service - Start switch for testing procedures. See page 32 Refer to Service - Timer for testing procedures. See page 34 or 35 Refer to Service - Dispense valve for testing procedures. See page 21 R[...]

Page 9 Automatic refill will not operate (cont.) Beverage level will not adjust (Selec- tor switch in any position) Water flows into tank continuously (ON/OFF Switch "OFF") Water from tank is not hot Refer to Service - Solenoid valve for testing procedures. See page 30 Refer to Service - Selector switch for testing procedures. See page 16[...]

Page 10 TROUBLESHOOTING (cont.) Water from tank is not hot (cont.) Server warmer is not hot. Spitting or unusual steaming from sprayhead or airvent. Inconsistent beverage level in server. 5. Triac assembly (DBC) 1. ON/OFF switch 2. Warmer element 1. (A) Control thermostat (Electro/ mechanical) (B) Digital Brewer Control 2. Triac assembly (DBC) 3. L[...]

Page 11 TROUBLESHOOTING (cont.) Inconsistent beverage level in server. (cont.) Consistently high or low beverage level in server. Dripping from sprayhead. Water overflows filter. Beverage overflows server. Weak beverage. 3. Dispense valve 1. (A) Time adjustment (Electro/ mechanical) (B) DBC volume adjustment 1. Dispense valve 1. Bypass valve (Elect[...]

Page 12 TROUBLESHOOTING (cont.) Weak beverage (cont.) Brewer is making unusual noises. Temperature on the DBC display varies. 3. Sprayhead 4. Funnel loading 5. Water temperature 1. Solenoid (Inlet) 2. Plumbing lines 3. Water supply 4. Tank heater 5. Contactor 1. Digital brewer control B.O.M. sprayhead #01082.0002 should be used to properly wet the [...]

Page 13 TROUBLESHOOTING (cont.) Cannot access the DBC DBC display is blank 1. Digital brewer control 1. Digital brewer control Refer to Service - Digital brewer con- trol for testing procedures. See page 22 step 7 Refer to Service - Digital brewer con- trol for testing procedures. See page 23 step 9 Problem Probable Cause Remedy 27362 092900[...]

Page 14 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. WARNING - Inspection, testing, and repair of electri- cal equipment should be performed only by qualified service pe[...]

Page 15 SERVICE (cont.) BYPASS VALVE Location: The bypass valve is located inside the hood on the left side just in front of the tank. Test Procedures: 1. Disconnect the brewer from the power source. 2. With a voltmeter, check the voltage across the white/green wire and the white/violet wire on the bypass valve. Connect the brewer to the power sour[...]

Page 16 5. Reattach the connector to the brew timer circuit board or DBC connector. Grinder Interface: 6. Disconnect pink, gray and tan wires on the selector switch from the pink, gray and tan wires on the interface socket. 7. Check for continuity across the pink wire and the tan wire on the selector switch when the switch is in the 1 gallon positi[...]

Page 17 SERVICE (cont.) BREW SELECTOR SWITCH (cont.) P1105.75 7. Install the knob so that the arrow lines up in the 2 gallon position when the switch is turned to the full right position. 8. Reattach the connector to the brew timer circuit board or DBC 9. Refer to Fig. 5 when reconnecting the wires. P1112.75 ELECTRO/MECHANICAL DIGITAL CONTROL (DBC)[...]

Page 18 SERVICE (cont.) CONTACTOR ASSEMBLY (ELECTRO/MECHANICAL ONLY) Location: The contactor assembly is located inside the hood to the right of the overflow cup. Test Procedures: Mechanical Thermostat 1. Disconnect the brewer from the power source. 2. Disconnect the white wire or the red wire and the black wire of the contactor coil and disconnect[...]

Page 19 Removal and Replacement: 1. Remove all wires from the contactor. 2. Remove the two #10-32 screws securing contactor to the inside of the hood. 3. Securely install the new contactor inside the hood. 4. Refer to Fig. 7 when reconnecting the wires. SERVICE (cont.) CONTACTOR ASSEMBLY (ELECTRO/MECHANICAL ONLY) (cont.) P1113 BLK T2 to Tank Heater[...]

Page 20 SERVICE (cont.) P1098 CONTROL THERMOSTAT (ELECTRO/MECHANICAL ONLY) Location: The control thermostat is located inside the front of the brewer in the center of the component bracket. Test Procedures: 1. Disconnect the brewer from the power source. 2. With a voltmeter, check the voltage across the blue wires on the control thermostat and the [...]

Page 21 DISPENSE VALVE N N x o p e r a t i n g p r e s s u r e l # 2 2 3 0 0 . 0 5 0 0 6 0 5 0 0 ) . 5 0 0 g p m F L O W J2 S ET L O C K L O CK SET T L 1 T L 2 T L 3 T L 4 T L 5 J 1 P2231.35 SERVICE (cont.) Location: Dispense valve is located inside the hood directly above the sprayhead. Test Procedures: 1. Disconnect the brewer from the power sour[...]

Page 22 Location The digital control board is located inside the upper front of the trunk on the component bracket. The digital display is located in the upper center of the front of hood. NOTE: Check the function list (supplied) for FUNC- TION, ENTRY AND DESCRIPTION. 1. If display indicates a "FAULT" use the list below to troubleshoot th[...]

Page 23 SERVICE (cont.) heater relay or triac. ("0" means the temperature will be allowed to vary by the value in "set relay temperature difference") 7. If you cannot access the DBC with the password you have entered, the password has been changed. If you know what the brew settings are you can "reset" the memory back [...]

Page 24 P1099 P1094.35 Location The triac/heat sink is located on the lower rear of the brewer. Removal and Replacement NOTE - each triac installation requires the use of an approved silicone heat sink compound. Bunn-O- Matic recommends the use of Dow Corning 340 com- pound or equivalent. It can be purchased direct from Bunn-O-Matic (part number M2[...]

Page 25 SERVICE (cont.) LEVEL CONTROL BOARD AND LEVEL PROBE (Electro/ mechanical only) Location: The level control board is located inside the front of the brewer on the lower left side of the component bracket. The level probe is located inside the hood on the left center rear of the tank lid next to the limit thermostat. Test Procedure: 1. Discon[...]

Page 26 LEVEL CONTROL BOARD AND LEVEL PROBE (Electro/ mechanical only)(cont.) P1100 SERVICE (cont.) b.) 200 to 240 volts ac for two wire 200 or 240 volt models after a delay of approximately 1 second. 17. Disconnect the brewer from the power source. If voltage is present as described, reinstall the probe, the level control board and level probe are[...]

Page 27 Location: The limit thermostat is located inside the hood on the tank lid to the left of the tank heater. Test Procedure: 1. Disconnect the brewer from the power supply. 2. Disconnect both black wires from the limit ther- mostat. 3. With an ohmmeter, check for continuity across the limit thermostat terminals. If continuity is present as des[...]

Page 28 SERVICE (cont.) ON/OFF (Warmer) SWITCH Location: The ON/OFF (Warmer) switch is located on the front of the hood to the right of the start switch. Test Procedure: 1. Disconnect the brewer from the power source. 2. Viewing the switch from the back remove the red or white wire from the upper right terminal and the black wire from the center te[...]

Page 29 Removal and Replacement: 1. Disconnect the red leads from the overflow pro- tection switch from the black wire from the termi- nal block or DBC board assembly and the blue wire from the thermostat or red wire from DBC board assembly. 2. Remove the nut beneath the copper overflow cup. 3. Remove the entire switch assembly from the cup. 4. Pla[...]

Page 30 SERVICE (cont.) SOLENOID VALVE (Refill) Location: The inlet solenoid valve is located inside the trunk on top of the flow control bracket. Test Procedure: 1. Disconnect the brewer from the power source. 2. Disconnect both wires from the solenoid valve coil terminals and check for continuity across the solenoid valve coil terminals. If conti[...]

Page 31 SERVICE (cont.) SOLENOID VALVE (Refill) (cont.) P1107 9. Slide flow control bracket and solenoid as an assembly over flow control and secure with four #8-32 screws to the support bracket. 10. Securely fasten the water lines to and from the solenoid valve and flow control. 11. Refer to Fig. 24 when reconnecting the wires. WHI to Level Contro[...]

Page 32 START SWITCH Location: The start switch is located in front of hood to the left of the ON/OFF switch. Test Procedure: 1. Disconnect the brewer from the power source and remove the wires from both terminals of the switch. 2. Check for continuity across the two terminals on the switch when it is held in the lower position. Continuity must not[...]

Page 33 Location: The tank heater is located inside the hood on the right rear of the tank lid. Test Procedure: Electro/Mechanical Models. 1. Disconnect the brewer from the power supply. 2 With a voltmeter, check the voltage across the black and the red wire on the tank heater. With the control thermostat turned to the "ON" position (full[...]

Page 34 SERVICE (cont.) TIMER (ELECTRO/MECHANICAL ONLY)(EARLY MODELS) tion. Select the 2 gallon batch setting. Connect the brewer to the power source and press the start switch. The indication must be: a.)120 volts ac for three wire 120/208 volt models and three wire 120/240 volt models for approxi- mately 1 minute 20 seconds for 2 gallon batch. b.[...]

Page 35 SERVICE (cont.) DIGITAL TIMER (ELECTRO/MECHANICAL ONLY) (LATE MODELS) B U N N 9 0 p s ig m a x o p e ra ti n g p re s s u re S t ra in e r/ F lo w C o n t ro l # 2 2 3 0 0 . 0 5 0 0 (R e p l. F lo w W a s h e r # 2 0 5 2 6 . 0 5 0 0 ) ( R e p l. S c re e n # 2 3 7 2 1 . 0 0 0 0 ) . 5 0 0 g p m F L O W J 2 S E T L O C K L O CK SET T L 1 T L [...]

Page 36 T imer Setting: NOTE: Prior to setting or modifying volumes, check that the brewer is connected to water supply , the tank is properly filled, and a funnel and server are in place. NOTE: All volume settings must be done with the sprayhead installed. NOTE: The timer must be adjusted for each individual batch setting. 1. Modifying brew volume[...]

Page 37 4. Disconnect wires from the warmer element. 5. Check the continuity across the two terminals on the warmer element. If continuity is present as described, reconnect the white or red wire and white/red wires, or the white or red wire and white/violet wires on the warmer element. If continuity is not present as described, replace the warmer [...]

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