Bunn U3 manual

U3 U3A OPERA TING & SER VICE MANUAL BUNN-O-MA TIC CORPORA TION POST OFFICE BOX 3227 SPRINGFIELD, ILLINOIS 62708-3227 PHONE: (217) 529-6601 F AX: (217) 529-6644 T o ensure you have the 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, a[...]

Page 2 10060 100908 BUNN-O-MA TIC 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 . 2) Electronic circuit and/or control boards: parts and labor for 3 years. 3) Compressors on refrigeration equipment: 5 years[...]

Page 3 W A RNING V e ry Hot W ater Use With Care! INTRODUCTION This brewer will brew a three gallon batch of coffee into each reser voir (one at a time). Each reser voir 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 where ambient temperature is in th[...]

Page 4 ELECTRICAL REQUIREMENTS CAUTION - The brewer must be disconnected from the power source until specified in Initial Set-Up. U333 & U3833 requires 3-wire, grounded ser vice rated 240 volt ac, 35 amp or 440 volts ac, 30 amp for U333,three phase, 60 Hz or 380 volts ac, 30 amp for U3833, three phase, 50 Hz. Proceed as follows: U3 & U38 r[...]

Page 5 INITIAL SETUP CAUTION - The brewer must be disconnected from the power source throughout the initial setup, except when specified in the instructions. IMPORT ANT : 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 [...]

Page 6 INITIAL SETUP (cont.) 6. Brewing 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. The recommended brewing temperature is approximately 200 ° F (93°C). Water temperature may be increased[...]

Page 7 COFFEE BREWING 1. Brewing 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 Bunn ® filter in funnel and add desired amount of coffee. 3. Level the bed of coffee and place funne[...]

Page 8 PROBLEM Brew cycle will not start PROBABLE CAUSE 1. No water 2. No power or incorrect voltage to the brewer REMEDY Water lines and valves to the brewer must be open. (A1) Check the terminal block for 120 volts ac across the red and white terminals and the black and white terminal on three wire 102/208 volt or 120/240 volt models. (A2 ) Chec [...]

Page 9 TROUBLESHOOTING (cont.) PROBLEM Brew cycle will not start (cont) Brew cycle starts with brew lockout relay engaged. PROBABLE CAUSE 2. No power or incorrect voltage to the brewer (cont) 3. Water level below pump housing. (Water level in the hot water gauge glass should be approximately half full). 4. ON/OFF Switch 5. Start Switch 6. Relay 7. [...]

Page 10 TROUBLESHOOTING (cont.) PROBLEM T ank not filling Water running out of the over - flow PROBABLE CAUSE 1.ON/OFF Switch (This switch must be in the "ON" position for the refill circuit to operate. 2. No water 3. Solenoid Valve 4. Probe 5. Liquid Level Board 1.Brewer not level 2. Solenoid Valve 3. Liquid Level Board 4. Probe 5. Ma[...]

Page 11 PROBABLE CAUSE 1. Limit Thermostat CAUTION - Do not eliminate or bypass limit thermostat. Use only Bunn-O-Matic replacement part #29329.1000 2. Control Thermostat 3. T ank Heater(s) 4. Contactor 1. Circuit Breaker 2. T ank Heater(s) 1. Timer 2. Start Switch 1. Timer 2. Solenoid Valve 3. Lime build-up in swing spout and pump tubing. 1. Filte[...]

Page 12 TROUBLESHOOTING (cont.) PROBLEM Funnels overflow (cont.) Coffee reservoir overflows Brewer is making unusal noises PROBABLE CAUSE REMEDY 3. Pump - Flow Rate 4. Soft Water 1. Coffee reser voir not completely empty befor a brew cycle was started. 2. Timer 3. Pump - Flow Rate 1. Solenoid Valve 2. Plumbing lines 3. Water supply 4. T ank Heate[...]

Page 13 SERVICE This section provides procedures for testing and replacing various major components used in this brewer should service become necessar y . Refer to T roubleshooting for assistance in determining the cause of any problem. WARNING - Inspection, testing, and repair of electri- cal equipment should be performed only by qualified servic[...]

Page 14 SERVICE (cont.) CIRCUIT BREAKER (120/208V and 120/240V Three Wire Models and 440V Four Wire Models) Location: The cir cuit breaker is located on the right rear of the component bracket. T est Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the black wire from the main harness from the circuit breaker and the white [...]

Page 15 P2209.60 FIG. 4 CONT ACTOR CONT ACTOR Location: The contactor is located on the left front of the component bracket T est Procedures: 1. Disconnect the brewer from the power source. 2A. 120/ 208V , 120 /240V , 38 0V THRE E WIRE MODEL S, 380V and 440V FOUR WIRE MODELS Disconnect the black wire from the contactor coil to the limit thermostat [...]

Page 16 RED to Left T ank Heater (T2) RED to T erminal Block(L2) BLK Thermal Fuse to Left T ank Heater BLK to left T ank Heater (L1) BLK to Right T ank Heater (T1) BLK to T erminal Block (L1) RED to Right T ank Heater (L2) WHI from Main Harness (120/208V ,120/240V ,380V Three Wire Models, 380V and 440V Four Wire Models) RED from Main Harness (208V [...]

Page 17 SERVICE (cont.) CONTROL THERMOST A T FIG. 6 CONTROL THERMOST A T P2209.60 Location: The control thermostat is mounted on the right front of the component bracket. T est Procedures: 1. Disconnect the brewer from the power source. 2. Locate the thermostat and the voltage check points. 3. Connect the brewer to the power source. Model 120/208V [...]

Page 18 SERVICE (cont.) FUSE AND FUSE HOLDER (208V , 240V , 230V T wo Wire Models and 380V Three Wire Models) Location: The fuse and fuse holder are located on the right rear of the component bracket. T est Procedures: 1. Disconnect the brewer from the power source. 2. Remove the cap and fuse from the fuse holder . 3. Remove fuse from the cap. 4. C[...]

Page 19 LIMIT THERMOST A T SERVICE (cont.) P1800 FIG. 11 LIMIT THERMOST A T TERMINALS FIG. 10 LIMIT THERMOST A T P2209.60 Location: The limit thermostat is located on the center front of the component bracket behind the timer mounting bracket. T est Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the black wires or the red[...]

Page 20 8. Disconnect the brewer from the power source and remove the jumper wire from terminal 4. 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. LIQUID LEVEL BOARD AND LEVEL PROBE FIG.12 LIQUID LEVEL BOARD AND LEVEL PROBE P2209.60[...]

Page 21 SERVICE (cont.) LIQUID LEVEL BOARD AND LEVEL PROBE (cont.) T1 BLU to Solenoid Valve T2 BLK to ON/OFF Switch (All models except 230V-CE models) T3 WHI to Main Harness (120/208V , 120/240V , four wire 380V and 440V models) T3 WHI to T ransformer (380V three wire models) T3 RED to Main Harness (208V , 240V single phase and three phase models) [...]

Page 22 5. Disconnect the wires on the ON/OFF switch. 6. a) 120/208V , 120/240V , 208V , 240V , 380V and 440V Models - Check for continuity across the terminals on the rear of the switch with the switch in the "ON" (upper) position. Continuity must not be present when the switch is in the "OFF" (lower) position. b) 230V - CE Mod[...]

Page 23 SERVICE (cont.) PUMP ASSEMBL Y FIG.16 PUMP ASSEMBL Y P2209.60 Location: The pump is located on the center rear of the component bracket. T est Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the black wire from the black lead on the pump and the white wire from the black lead on the pump. 3. With a voltmeter , chec[...]

Page 24 RELA Y (BREWERS W/BREW LOCKOUT) FIG.18 RELA Y P1731.55 Location: The relay is located on the front part of the com - ponent bracket, mounted on the top of the timer bracket. T est Procedures: All Models Except 230V - CE Models 1. Disconnect the brewer from the power source. 2. Disconnect the wires from relay terminals "A" & &q[...]

Page 25 SERVICE (cont.) RELA Y (BREWERS W/BREW LOCKOUT) B 9 6 8 5 7 B 6 9 8 5 A 1 4 7 2 3 A 1 4 2 3 120/208V , 120/240V , 208V , 380V , 440V AND 240V MODELS PRIOR TO #U300004095 230V MODELS #U300004095 AND UP FIG.19 RELA Y TERMINALS P1739 RED from Main Harness BLU from Brew Timer BLK to Control Thermostat BLU to Start Switch BLU from Brew Timer BLK[...]

Page 26 SELECTOR SWITCH (HALF BA TCH OPTION) FIG. 20 SELECTOR SWITCH (HALF BA TCH) Location: The selector switch is located in the upper center of the switch mounting panel. T est Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the wires from the switch terminals. 3. Check for continuity across the switch terminals with th[...]

Page 27 SERVICE (cont.) SOLENOID FIG. 22 SOLENOID P2209.60 Location: The solenoid is mounted on the upper left rear of the component bracket. T est Procedures: 1 . Disconnect the dispenser from the power source. 2. 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 fo[...]

Page 28 SERVICE (cont.) SOLENOID 6. Remove the tank inlet tube grommet and dis- card. 7. Install new tank inlet tube grommet. 8. Install new solenoid assembly . 9. Inst all liqu id leve l board, shield and secure soleno id assembly and shield to the component bracket with a #10-32 screw and flat washer .. 10. Install water inlet tube to connector [...]

Page 29 ST ART SWITCH (BREW) FIG. 24 ST ART SWITCH (BREW) P1317.30 Location: The brew start switch is located on the upper right side of the brewer component housing. T est Procedures: 1. Disconnect the brewer from the power source. 2. Remove the wires from the start switch termi- nals. 3. Check for continuity across the switch terminals when the s[...]

Page 30 BLK to Contactor T1 (All Models Except 230V-CE Models) BLK (Thermal Fuse) to Contactor T op Left T ermi - nal) (230V-CE Models) RED to Contactor T2 (All Models Except 230V-CE Models) RED (Thermal Fuse) to Con- tactor T op Right T erminal) (230V-CE Models) BLK to Contactor L1 (1 20/2 08V , 120/ 240 Th ree Wire Single Phase, 208V and 240V T w[...]

Page 31 SERVICE (cont.) THERMAL FUSES (230V-CE MODELS ONL Y) J 2 TL1 TL 2 TL 3 TL 4 T L5 J1 FIG. 28 THERMAL FUSES P1750.65 Location: The thermal fuses are mounted on the tank heater terminals and the contactor terminals. T est Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the thermal fuse from the tank heater terminal an[...]

Page 32 SERVICE (cont.) TIMER (Early Models)(cont.) 5. With a voltmeter , check the voltage across the sockets P1 and P2 (blue and white wires) of the female connector on the main harness when the "ON/OFF" switch is in the "ON" (upper) position and the start switch pressed. Connect the brewer to the power source. The indication [...]

Page 33 DIGIT AL TIMER (Late Models) FIG. 32 DIGIT AL TIMER P2209.60 SERVICE (cont.) Location: The timer is located on the front center of the component bracket. T est Procedure. NOTE: Do not remove or install wires while timer board is installed. Pressure applied to one side may cause damage to the board. 1. Disconnect the brewer from the power so[...]

Page 34 SERVICE (cont.) DIGIT AL TIMER (Late Models) BLU/BLK wire from TL5 to P1 WHI/GRN wire from TL4 to (WHI) Pump WHI/BLU wire from TL3 to (BLK) Pump WHI wire from TL2 to P2 BLK wire from TL1 to P3 J2 - Three Pin connector from Half/Full Batch Switch P2037 FIG. 33 DIGIT AL TIMER TERMINALS NOTE: All volume settings must be done with the sprayhead[...]

Page 35 BLK from T erminal Block SERVICE (cont.) TRANSFORMER (380V THREE WIRE MODELS ONL Y) FIG. 34 TRANSFORMER P1752.55 Location: The transformer is located on the top rear of the timer mounting bracket. T est Procedures: 1. Disconnect the brewer from the power source. 2. Disconnect black wire and the red wire from the terminal block at the transf[...]

Page 36 MASTER ON/OFF SWITCH (Late Models) SERVICE (cont.) FIG. 37 MASTER ON/OFF SWITCH WIRING Location: The Master ON/OFF switch is located in the top hous- ing at the rear , FIG. 36. T est 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 t[...]

Page 37 N L1 L2 WHI BLK RED MAIN ON/OFF SWITCH (Late Models only) RED BLK 10492.0000E 03/07 © 1990 BUNN-O-MA TIC CORPORA TION 120/208 VO LT S AC 120/240 VO LT S AC 3 WIRE + GND SINGLE PHASE 10060 011708[...]

Page 38 10060 080900[...]

Page 39 SCHEMA TIC WIRING DIAGRAM U3A & U38A (BREWERS PRIOR TO U300004095) 10060 080900[...]

Page 40 SCHEMA TIC WIRING DIAGRAM U3A - CE (BREWERS S/N U300004095 - UP) 10060 080900[...]

Page 41 SCHEMA TIC WIRING DIAGRAM U3833 10060 080900[...]

Page 42 SCHEMA TIC WIRING DIGRAM U3833 10060 080900[...]