SERVICE MANUAL C24GA SERIES CONVECTION STEAMERS MODELS C24GA6 ML-136021 C24GA10 ML-136022 - NOTICE This manual is prepared for the use of trained Vulcan Service Technicians and should not be used by those not properly qualified. If you have attended a Vulcan Service School for this product, you may be qualified to perform all the procedures described in this manual. This manual is not intended to be all encompassing.
C24GA SERIES CONVECTION STEAMERS TABLE OF CONTENTS GENERAL................................................................................................................................................................ Introduction ....................................................................................................................................................... Installation ..................................................................................................................
C24GA SERIES CONVECTION STEAMERS ELECTRICAL OPERATION .................................................................................................................................... Water Level Controls ...................................................................................................................................... Low Level Cut-Off & Differential Control .................................................................................................... Sequence of Operation .....
C24GA SERIES CONVECTION STEAMERS - GENERAL GENERAL INTRODUCTION TOOLS Procedures in this manual will apply to all models unless specified. Pictures and illustrations can be of any model unless the picture or illustration needs to be model specific. Standard • Standard set of hand tools. • VOM with A.C. current tester (Any quality VOM with a sensitivity of at lease 20,000 ohms per volt can be used.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS REMOVAL AND REPLACEMENT OF PARTS Cooking Compartment Left Side Panel COVERS AND PANELS 1. WARNING: DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES. Remove the screws then remove the left side panel from the compartment. Cooking Compartment Right Side Panel 1. Remove the screws then remove the right side panel from the compartment. Cabinet Base Right Side Panel 1.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS Cabinet Base Left Side Panel Cabinet Base Rear Panel 1. 1. Remove the screws then remove the left side panel from the cabinet base. COOKING COMPARTMENT DOOR Cabinet Base Front Panel 1. Remove the screws then remove the front panel from the cabinet base. F35425 (February 2006) Remove the screws then remove the rear panel from the cabinet base. Door Assembly 1. Remove compartment left side panel as outlined under COVERS AND PANELS.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS Door Gasket 1. Open the door. 2. Remove screws from the gasket guard and gasket plate. 3. Remove the gasket guard and the gasket plate. 4. Position the new gasket on the gasket plate. 5. Reverse the procedure to install. 6. Adjust the door as outlined under SERVICE PROCEDURES AND ADJUSTMENTS. 4. Remove the plate, nuts, washers and spacers from the handle screws and remove the door handle from the door. 5.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS Door Latch Assembly COMPARTMENT CONTROLS 1. Open the door. 2. Remove screws from the top and bottom of the door. 3. Pull the outer door panel out from the door housing. 4. Remove the pins and retaining rings. 5. Remove the latch assembly from the door. 6. Reverse procedure to install. Use Loctite 271 to secure fasteners.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS MAIN BURNER WARNING: DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES. 1. Remove front and side covers as outlined under COVERS AND PANELS. 2. Disconnect the gas line at gas combination control valve. 3. Disconnect wires to burner assembly. 4. Remove the nuts securing burner to tank. 5.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS 1. Drain the generator and allow steamer to cool, if necessary. 2. Remove rear and side panels as outlined under COVERS AND PANELS. 3. Disconnect gas line at gas combination control valve. 4. Disconnect wires to burner assembly. 5. Disconnect wires from gas combination control valve. 6. Remove the nuts securing the burner to generator. 7.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS 19. Move any interfering components out of the way, then push generator slightly forward to disengage feet and remove generator from rear of cabinet. 20. Reverse procedure to install generator. FILL AND COLD WATER SOLENOID VALVES WARNING: DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AND FOLLOW LOCKOUT / TAGOUT PROCEDURES. 1. Turn off the water supply to the steamer. 2. Remove front and side covers as outlined under COVERS AND PANELS.
C24GA SERIES CONVECTION STEAMERS - REMOVAL AND REPLACEMENT OF PARTS 4. Disconnect the water lines for the solenoid valve being serviced and remove the solenoid valve from the unit. 5. Reverse procedure to install solenoid valve. PILOT/SPARK PROBE FLAME SENSOR 1. Remove main burner assembly as outlined under MAIN BURNER in REMOVAL AND REPLACEMENT OF PARTS. 2. Remove the pilot assembly by disconnecting gas tube to the pilot burner and remove screws holding pilot assembly. 3.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS SERVICE PROCEDURES AND ADJUSTMENTS WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TEST OR MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER AND FOLLOW LOCKOUT / TAGOUT PROCEDURES, ATTACH TEST EQUIPMENT AND REAPPLY POWER TO TEST.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS The screw head should not extend out past the screw housing. 1) If gas valve energizes, proceed to step 5. 1. Shut the gas off at combination gas valve. 2. Remove cover from manifold pressure tap. 2) If gas valve does not energize, check the following: 3. Install a barb fitting and connect manometer. 4. Turn on the steamer, let generator fill. 5. Verify air pressure setting is between 0.35" and 0.4" W.C. 6.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS 2. Turn the power on and let the generator come up to pressure. 3. After the ready light comes on, turn one of the cooking compartment timers on to exhaust steam from the generator. 4. Observe generator pressure gauge reading for several cycles and verify that the burner is cycling off at 3.5 to 4 psi. 16. Turn off the machine. 17. Re-install pilot, reconnect wire # 35. 18. Turn on the machine, let generator fill 19.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS Thumb Wheel Adjustment Inlet Water/Steam Strainer The thumb wheel directly below the microswitch changes both the cut-out (off) and the cut-in (on) points of the operating Pressure Switch. Turn the thumb wheel to obtain the proper cut-out (off) setting. Turning thumb wheel clockwise increases the pressure. The cut-out (off) off setting should be 3.5 to 4 psi. F35425 (February 2006) 1. Unscrew the cap from the body. 2.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS AUTOMATIC IGNITION SYSTEMS When the main power switch is turned on and the water level is above LLCO, the ignition control module is energized with 24 volts between terminals five and six. High voltage is sent from terminal nine to the spark electrode and an output of 24 volts is sent from terminals two and three to the pilot coil in the combination valve, allowing gas to flow to the pilot.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS A. If 24VAC is present, then replace ignition control module and retest. It may take up to 3 seconds for the module to reset if main power is turned off then back on. B. If 24VAC is not present, then ensure that transformer is receiving 120VAC input. If ignition control module transformer is receiving proper voltage, then replace ignition control module transformer and retest. 2. 3. 4.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS 5. Verify burner air pressure is 0.35" to 0.4" W.C. 5. 6. Turn the gas combination control valve on and wait until main burner lights. Check wiring for damaged insulation (no short circuit). 6. Observe the manometer pressure reading and compare to the pressure chart below. Check that all connections and terminals are securely fastened (no open circuits). 7.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS Striker Adjustment • Safety goggles or face shield. 1. Reinstall the striker with the slot pointing upwards and hand tighten nut only. • Measuring cup. • 1 gallon container for mixing deliming solution. 2. Close the door to center the striker in the oval mounting hole. • Petrol-Gel Lubricant or equivalent food grade grease for coating deliming port threads. 3.
C24GA SERIES CONVECTION STEAMERS - SERVICE PROCEDURES AND ADJUSTMENTS 10. After 40 minutes, turn power switch off and allow steam generator to completely drain, 5 minutes. 11. Rinse steam generator with clean water: A. Turn power switch on. When ready light comes on, turn cooking timers on for 30 seconds to rinse the steam tubes and nozzles. B. Turn power switch off and allow steam generator to completely drain. C. Turn cooking timers to off. D. Repeat steam generator rinse one time. 10.
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION ELECTRICAL OPERATION contacts open, the generator fill solenoid is deenergized, stopping the flow of water into the generator. WATER LEVEL CONTROLS Low Level Cut-Off and Differential Control The steamer is equipped with three water level sensing probes (high, low and low level cut-off) and a single water level control board. The water level control board performs two functions: 1.
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION 1. Turn power switch on. A. B. a. Air pressure switch. 1) b. Blower motor. c. Step-down transformer which removesvoltage from ignition module. Operating voltage applied to control compartment after cavity relay is latched on. Water level control (WLC) energized. Low level (LL) relay N.C. contacts provide operating voltage to fast-fill solenoid. a. 2) Fast-fill solenoid energized, water begins filling the generator. 2) a. LL relay N.C.
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION Compartment control (Units after Dec. 1, 2005) Refer to schematic diagrams 00855693 & 00856656. 1. Compartment door closed causing door switch to close and Ready Light to illuminate. A. 120 VAC applied through door switch to timer contact 11 and 21. B. Timer manually set to desired time period. C. Voltage applied through contacts 11 and 13. D. 2. 1) Timer begins countdown. 2) Voltage applied through contacts 21 and 23.
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION SCHEMATIC DIAGRAMS Generator Schematic Diagram Page 25 of 40 F35425 (February 2006)
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION Schematic Diagram - Compartment Controls (Standard) F35425 (February 2006) Page 26 of 40
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION Schematic Diagram - Compartment Controls (Constant Steam) Page 27 of 40 F35425 (February 2006)
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION COMPONENT LOCATION CABINET BASE GENERATOR F35425 (February 2006) Page 28 of 40
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION COMPONENT FUNCTION CABINET BASE GENERATOR Water Level Control and Level Sensing Probes................... The Water Level Control circuit board and Level Sensing Probe Assembly allow water to enter the generator to fill and maintain the proper water level. These probes will also shut off the heat source to the generator if the water level drops too low. The water level control works by using three different probe lengths to monitor the water level.
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION Hold Thermostat........................... The Hold Thermostat energizes the Generator Slow Fill Solenoid Valve when generator temperature reaches the non-adjustable setpoint at 190°F. Drain............................................. The Drain is located on the lower right of the base and removes steam condensate and water from cooking compartments and generator. Metal Fiber Main Burner...............
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION COMPONENT LOCATION COOKING COMPARTMENT Page 31 of 40 F35425 (February 2006)
C24GA SERIES CONVECTION STEAMERS - ELECTRICAL OPERATION COMPONENT FUNCTION COOKING COMPARTMENT General The upper section of the steamer consists of two separate cooking compartments. Each compartment functions independently with its own set of controls. Power is supplied to the controls only after the steam pressure rises above 4 psi to energize the compartment latching relay. The relay remains energized as long as Main Power Switch is on. Ready Light (Green)......................
C24GA SERIES CONVECTION STEAMERS - TROUBLESHOOTING TROUBLESHOOTING General Water Accumulating in Compartment The following paragraphs provide descriptive information of the most common troubles that can occur in the steamer. The Troubleshooting Chart provides a list of other typical fault conditions. The left-hand column of the table lists typical symptoms and the right-hand column lists probable causes and the suggested remedies.
C24GA SERIES CONVECTION STEAMERS - TROUBLESHOOTING TROUBLESHOOTING SEQUENCE OF OPERATION STEP FUNCTION DESCRIPTION 1 Power On Power Switch is switched to the on position. 2 Fill Stage 1 Boiler fills with fast fill water valve, (3.7 GPM). 3 Low Level Probe Confirmation Low Level Probe, (LLCO), is confirmed then power is applied to burner system, fast fill valve is turned off. 4 Burner Operation Power is supplied to operating pressure switch.
C24GA SERIES CONVECTION STEAMERS - TROUBLESHOOTING TROUBLESHOOTING CHART SYMPTOM Compartment leaks steam or water around door. Cold water condenser not operating properly. Steam visible inside compartment when unit is not in cook mode. Heat coming on without water in. Pressure relief valve opening or leaking. Generator will not heat or build pressure. Steam output low or slow cooking. Unit leaks water. Generator water level too high. POSSIBLE CAUSES 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. 1. 2. 1. 2. 1. 2. 3.
C24GA SERIES CONVECTION STEAMERS - TROUBLESHOOTING SYMPTOM Generator does not fill. Timer motor does not run. Door not closing properly. Door won’t open or hard to open. Buzzer not operating. Burner won’t light or won’t stay lit. Pilot not lit or goes out. POSSIBLE CAUSES 1. 2. 3. 4. 1. 2. 3. 4. 5. 1. 2. 1. 2. 3. 4. 1. 2. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 1. 2. 3. 4. 5. 6. 7. F35425 (February 2006) Water supply not on. Fill solenoid not opening or plugged.
C24GA SERIES CONVECTION STEAMERS - TROUBLESHOOTING SYMPTOM Spark igniter not sparking. POSSIBLE CAUSES 1. 2. 3. 4. 5. 6. 7. 8. 9. Incorrect spark gap setting. Poor ground between pilot bracket and burner. Loose, broken or damaged lead wires (including ground) from ignition module to ignitor. Ignitor boot on ignition cable loose, damaged or missing causing excessive ignition voltage leakage. Ceramic flame rod insulator on ignitor cracked or damaged from extreme heat. Ignition module not receiving power.
C24GA SERIES CONVECTION STEAMERS - CONDENSED SPARE PARTS LIST CONDENSED SPARE PARTS LIST C24GA SERIES CONVECTION STEAMERS PART NO.
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