BUNN ® U3A OPERATING & SERVICE MANUAL BUNN-O-MATIC CORPORATION POST OFFICE BOX 3227 SPRINGFIELD, ILLINOIS 62708-3227 PHONE: (217) 529-6601 FAX: (217) 529-6644 10060.0003A 07/02 ©2002 Bunn-O-Matic Corporation www.bunnomatic.
INTRODUCTION This brewer will brew a three gallon batch of coffee into each reservoir (one at a time). Each reservoir has its own dispensing faucet(s).The brewer also has a hot water faucet(s) for allied beverage use. It is only for indoor use on a sturdy counter. BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTY Bunn-O-Matic Corp. (“BUNN”) warrants equipment manufactured by it as follows: 1) All equipment other than as specified below: 2 years parts and 1 year labor.
USER NOTICES Carefully read and follow all notices on the brewer 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. #00656.0000 #00831.0000 ATTENTION: TURN OFF WHEN UNATTENDED #00878.0000 #10044.0000 #03408.0000 #12593.0000 #03409.0000 #12555.0000 #29299.0000 Page 3 10060.
ELECTRICAL REQUIREMENTS CAUTION - The brewer must be disconnected from the power source until specified in Initial Set-Up. P2226 Requires 2-wire, gorunded service rated 230 volts ac, 32 Amps, single phase, 50 Hz. FACTORY WIRED Requires 4-wire, 3-phase grounded service rated 400 volts ac, 15 amp, 3 phase, 50 Hz. FIELD WIRING ELECTRICAL INSTALLATION INSTRUCTIONS CAUTION – Improper electrical installation will damage electronic components. 1. An electrician must provide electrical service as specified. 2.
INITIAL SETUP CAUTION - The brewer must be disconnected from the power source throughout the Initial Setup, except when specified in the instructions. IMPORTANT: Brewer must be level and installed on a sturdy structure. Electrician's and Plumber's Instructions are provided. These instructions should be carefully followed before proceeding with Initial Setup. Be sure all electrical and plumbing connections are tight. 1. Open manual fill valve located on the bottom of the brewer.
ADJUSTING BREW VOLUMES CAUTION - Disconnect the power source from the brewer prior to the removal of any panel for the replacement or adjustment of any component. NOTE: Prior to setting or modifying batch sizes, check that the brewer is connected to water supply, the tank is properly filled, and a funnel support, funnel and funnel cover are in place. 1. Modifying batch sizes. To modify a batch volume, first check that the SET/LOCK switch is in the “SET” position on the circuit board.
COFFEE BREWING 1. Brew cycles may be started whenever water temperature is correct. This condition is indicated by the dial thermometer on front of the brewer. Whenever the pointer is in the green, brewer is ready for brewing. 2. Insert a Bunn® filter in funnel and add desired amount of coffee. 3. Level the bed of coffee and place funnel into the funnel support. Place funnel cover over the funnel and be sure the water swing spout is over the center of the funnel cover. 4.
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 qualified service personnel. All electronic components have 230 volt ac and low voltage dc potential on their terminals.
TROUBLESHOOTING (cont.) PROBLEM PROBABLE CAUSE REMEDY Brew cycle will not start (cont.) 6. Start Switch Refer to Service - Start Switch for testing procedures. See page 23 7. Timer Refer to Service - Timer for testing procedures. See page 26 or 28 8. Pump Refer to Service - Pump for testing procedures. See page 20 9. Solenoid Valve Refer to Service - Solenoid Valve for testing procedures. See page 22 10. Strainer (A) Direction of flow arrow must be pointing towards brewer.
TROUBLESHOOTING (cont.) PROBLEM PROBABLE CAUSE REMEDY Water running out of the overflow 1. Brewer not level Brewer must be level and installed on a sturdy structure. 2. Solenoid Valve Refer to Service - Solenoid Valve for testing procedures. See page 22 3. Liquid Level Board Refer to Service -Liquid Level Board for testing procedures. See page 17 4. Probe Refer to Service - Probe for testing procedures. See page 17 5. Manual fill and drain valve underneath brewer open. Be sure valve is closed.
TROUBLESHOOTING (cont.) PROBLEM PROBABLE CAUSE REMEDY Fuse opening 1. Fuse Refer to Service - Fuse for testing procedures. See page 16 2. Tank Heater(s) Refer to Service - Tank Heater for testing procedures. See page 25 1. Timer Refer to Service - Timer for testing procedures. See page 26 or 28 2. Start Switch Refer to Service - Start Switch for testing procedures. See page 23 1. Timer Refer to Service - Timer for testing procedures. See page 26 or 28 2.
TROUBLESHOOTING (cont.) PROBLEM PROBABLE CAUSE REMEDY Coffee reservoir overflows 1. Coffee reservoir not completely empty before a brew cycle was started. Be sure coffee reservoir is empty before brew cycle is started. 2. Timer Refer to Service -Timer for testing procedures. See page 26 or 28 3. Pump - Flow Rate Check pump flow rate with a watch. Pump flow rate should be approximately 24 ounces in 15 seconds. Be sure pump assembly is free of any obstructions. 1.
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 electrical equipment should be performed only by qualified service personnel. The brewer should be unplugged when servicing, except when electrical tests are required and the test procedure specifically states to plug in the brewer.
SERVICE (cont.) CONTACTOR (cont.) Test Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the red wire from the limit thermostat to the contactor coil and the black wire from the main harness to the contactor coil. 3. Connect the brewer to the power source. 4. Check the voltage across the limit wire and the wire from the the main harness.The indication must be 230 volts ac. 5. Disconnect the brewer from the power source. If voltage is present as described, proceed to #6.
SERVICE (cont.) CONTROL THERMOSTAT P2178.60 FIG. 4 CONTROL THERMOSTAT Location: The control thermostat is mounted on the right front of the component bracket. Test Procedures: 1. Disconnect the brewer from the power source. 2. Locate the thermostat and check for 230 volts between the red wire from the main harness on the control thermostat and the black wire on the main terminal block 3. Disconnect the brewer from the power source. If voltage is present as described, proceed to #4.
SERVICE (cont.) Removal and Replacement: Fuse: 1. Remove the cap from the fuse holder. 2. Remove fuse from the fuse holder, inspect, if blown discard. 3. Install new 5 amp fuse in the fuse holder. 4. Reinstall fuse holder cap. FUSE AND FUSE HOLDER Fuse Holder: 1. Disconnect the wires from the rear of the fuse holder. 2. Remove the nut securing the fuse holder to the component bracket. 3. Push fuse holder through the hole in the component bracket. 4.
SERVICE (cont.) LIQUID LEVEL BOARD AND LEVEL PROBE LIMIT THERMOSTAT FIG. 8 LIMIT THERMOSTAT P2178.55 Location: The limit thermostat is located on the center front of the component bracket behind the timer mounting bracket. Test Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the red wires from the limit thermostat. 3. Check for continuity across the limit thermostat terminals with an ohmmeter. If continuity is present as described, the limit thermostat is operating properly.
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.
SERVICE (cont.) ON/OFF SWITCH 5. Disconnect all wires on the ON/OFF switch. 6. Check for continuity across the center terminal (2) and the lower terminal (1) when the switch is in the "ON" (upper) position. Continuity must not be present when the switch is in "OFF" (lower) position. If continuity is present as described, the switch is operating properly. If continuity is not present as described, replace the switch. FIG.12 ON/OFF SWITCH P2104.
SERVICE (cont.) 4. Remove the four #8-32 screws (6) securing the pump assembly (4) to the component bracket (7). 5. Remove pump assembly (4). 6. Remove pump gasket (5) and inspect, replace if necessary. 7. Position gasket (5) on component bracket (7). 8. Install new pump assembly (4) on component bracket (7) and secure with four #8-32 screws (6). 9. Install fill tube (1) on pump assembly (4). 10. Slide clamp (3) down into position on the fill tube (1) and tighten screw (2). 11. Refer to Fig.
SERVICE (cont.) Removal and Replacement: 1. Remove the wires from the switch terminals. 2. Compress the clips on the back side of the switch mounting bracket and gently push them through the opening. 3. Push the new switch into the opening and spread the clips to hold switch in the mounting bracket. 4. Refer to Fig. 17 and reconnect the wires. SELECTOR SWITCH (HALF BATCH OPTION) P2104.25 FIG.
SERVICE (cont.) SOLENOID 7. Check the solenoid valve for coil action. Connect the dispenser to the power source. Listen carefully in the vicinity of the solenoid valve for a "clicking" sound as the coil magnet attracts. If the sound is heard as described and water will not pass through the solenoid valve, there may be a blockage in the water line before the solenoid valve or, the solenoid valve may require inspection for wear, and removal of waterborne particles.
SERVICE (cont.) START SWITCH (BREW) Removal and Replacement: 1. Remove the wires from the switch terminals. 2. Compress the clips on the back side of the switch mounting bracket and gently push them through the opening. 3. Push the new switch into the opening and spread the clips to hold switch in the mounting bracket. 4. Refer to Fig. 21 and reconnect the wires. FIG. 20 START SWITCH (BREW) P2104.25 Location: The brew start switch is located on the upper right side of the brewer component housing.
SERVICE (cont.) SWING ARM SWITCH If continuity is present as described, the switch is operating properly. If continuity is not present as described, replace the switch. P2168.50 FIG. 22 SWING ARM SWITCH Location: The swing arm switch is attached to the cupola cover. Removal and Replacement: NOTE: Measure the distance from the top of the switch plunger to the hood cover. The same distance is needed when the new switch is installed. 1. Remove nut securing switch to hood cover and remove switch. 2.
SERVICE (cont.) TANK HEATERS Test Procedures: 1. Disconnect the 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 operating properly. If continuity is not present as described, replace the tank heater. FIG. 24 TANK HEATER P2178.55 Location: Removal and Replacement: 1. Remove the thermal fuses from the tank heater. 2.
SERVICE (cont.) TIMER (Early Models) THERMAL FUSES OLD STYLE FIG. 27 TIMER FIG. 26 THERMAL FUSES P2178.55 P2179.65 Location: Location: The thermal fuses are mounted between the tank heater terminals and contactor terminals or terminal block. Test Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the thermal fuses from the tank heater terminal and the contactor terminal or terminal block. 3. Check for continuity across the terminals on the ends of each thermal fuse.
SERVICE (cont.) TIMER (Early Models)OLD STYLE(cont.) If voltage is present as described, proceed to #8. If voltage is not present as described, refer to the wiring diagram and check the brewer wiring harness. Three Pin Connector from Half/Full Batch Switch 8. Disconnect the black and white wires to the swing arm switch and pump leads. 9.
SERVICE (cont.) 6. With a voltmeter, check the voltage across terminals TL1 and TL4 when the "ON/OFF" switch is in the "ON" position. Connect the brewer to the power source. The indication must be 0 volts. DIGITAL TIMER (Late Models) If voltage is as described, proceed to #7. If voltage is not as described, disconnect the brewer from the power source and replace the timer. 7. With a voltmeter, check the voltage across terminals TL1 and TL4 when the "ON/OFF" switch is in the "ON" position.
SERVICE (cont.) DIGITAL TIMER (Late Models) 1. Modifying brew volumes. To modify a brew volume, first check that the SET/LOCK switch is in the “SET” position on the circuit board. To increase a brew volume, place the ON/OFF switch in the “ON” position, press and hold the START switch until you see three breaks in the water stream from the swing arm. Release the switch and press it again one or more times.
10493.0004A 07/02 © 2002 BUNN-O-MATIC CORPORATION Page 30 10060.
