Vulcan-Hart Vulcan Steamer Electrical Operation and Water Level Control Guide
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VHX SERIES STEAMER - ELECTRICAL OPERATION

ELECTRICAL OPERATION

WATER LEVEL CONTROLS

Low Level Cut-Off & 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 (solid state). The water level control board performs two functions: 1) Provide low level cut-off protection to shut off the heat source in case the water level drops below the low level cut-off (LLCO) probe. 2) Perform as a differential level control to maintain the water level between the low and high water level probes.

The water level control (WLC) has input voltage (120VAC) across terminals 11 and 12 which powers the primary side of the transformer. On one side of the transformer secondary, power is provided to the control by a series path through chassis ground (terminal 10). The other side of the transformer secondary (12VAC) is attached to the probe that directs power to the other side of board relay coils (LLCO and HL) and to the Inverse Latching Relay (ILR) electronic circuit on the board. As water enters the boiler, it becomes part of the water level control’s circuit. When the water level in the boiler reaches a probe, that circuit is completed.

The inverse latching relay of the board is de- energized, leaving the ILR-1 (N.O.) and ILR-2 (N.C.) contacts in their shelf state.

When the main power switch is turned ON, power is supplied to the WLC board which energizes the high level (HL) relay, closes HL-3 normally open contacts, and illuminates the HL relay LED. With the HL-3 contacts closed, the boiler fill solenoid is energized and water begins filling the boiler.

When the water level reaches the low level cut-off (LLCO) probe, the LLCO relay is energized and illuminates the LLCO LED. With the LLCO-2 contacts closed the heat source is then energized. The LLCO relay will remain energized and its LED will stay lit until the water level in the boiler drops below the LLCO probe. NOTE: Auxiliary control(s) in the heating circuit must also be satisfied before heating can start.

When the water level reaches the low level (LL) probe, power to terminal 2 on the WLC board is present but no switching occurs.

After the water level reaches the high level (HL) probe, the inverse latching relay of the board is energized and locked through the low level probe

(LL)and ILR-1 contacts. With ILR-2 contacts open, this de-energizes the HL relay and the HL LED goes out. With the HL-3 contacts open, the boiler fill solenoid is de-energized, stopping the flow of water

into the boiler.

When the water level drops below the low level (LL) probe, power is removed from the inverse latching relay, the HL relay energizes through ILR-2 and HL contacts change state. The fill solenoid is energized through HL-3 to refill the boiler and the HL LED is lit. The HL relay and LED will toggle ON and OFF during a cooking cycle as needed.

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F24700 (October 2001)

 

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Contents VHX24G Shown VHX Boiler Base Series High Efficiency GAS SteamersTable of Contents VHX Series Steamers General InstallationMaintenance Cleaning Introduction Boiler Control Styles System Water Conditioning SpecificationsWater Supply ElectricalGas Supply ToolsStandard SpecialCabinet Base Boiler Steamer OperationCooking Compartment Controls VHX Series Steamers OperationBoiler Blowdown Steamer Shut OFF VHX Series Steamers Component Function Component FunctionBlowdown/Drain Ignition Control ModuleWater Level Steam Header AssemblyWater Inlet Valve manual Pressure Relief ValveSteam Solenoid Valve Compartment Pressure SwitchManifold Pressure Gauge Steam Supply ManifoldVHX Series Steamers Removal and Replacement of Parts Removal and Replacement of PartsComponent Locations Cabinet Base Boiler ControlsCabinet Base Boiler Controls Cooking Compartment Controls Water Level Controls Main or Auxiliary LlcoRelay Board Boiler Assembly Water Level Gauge AssemblyPressure Switches Boiler Fill and Cold Water Condenser Solenoid Valves Pilot GAS Valve Main GAS ValveComplete Burner Assembly Burner Head AssemblyHeat Exchanger VHX Series Steamers Removal and Replacement of Parts Gasket Cooking Compartment DoorsRemoval Handle Latch AssemblyClean-Out Service Procedures and AdjustmentsBoiler InspectionDescaler Cathodic Protector Water Level Probe Housing BlowdownTest Water Level ControlsAuxiliary Low level Cut-Off Control Cycling High LimitSmall increments Fill and Cold Water Solenoid ValvesBoiler BLOWDOWN/DRAIN Solenoid Valve Inline Water Strainer CleaningMain Burner Ignition Checks Pressure Switch AdjustmentGAS Manifold Pressure Adjustment VHX Series Steamer Service Procedures and Adjustments AIR Pressure Switch Adjustment GAS Pilot Pressure Adjustment Pressure Readings Inches W.C GAS Manifold Pressure Adjustment Terminals Ignition Control Module ChecksSpark Verification Test Door Sealing Adjustment Intake Shut-Off Valve Adjustment Steam FlowCooking Compartment Cooking Compartment DoorsVHX Series Steamer Electrical Operation Door Latch AdjustmentLow Level Cut-Off & Differential Control Electrical OperationAuxiliary Low Level Cut-Off LED Legend Board Layout and LED LegendReset Engaged State C Boiler Operational Status LED IndicatorInitial Conditions State a Aux Water Level Satisfied State BK32 Close Air Pressure Switch Satisfied State DK51 Close Burner ON, Boiler Heating to generate steam State ENEW Style Controls Boiler Sequence of OperationInitial Fill and Preheat HL-LEDN14, N16, N17 go out N9, N10, N11, N12, N13 go outBoiler Blowdown/drain Water Refill After Initial FillVHX Series Steamer Electrical Operation Cooking Compartment Controls This page Intentionally Left Blank Models Built After 5/25/00 New Style Boiler Controls SchematicsVHX Series Steamer Electrical Operation Models Built Before 5/25/00 Old Style Boiler Controls Cooking Compartment Controls Wiring Diagrams VHX Series Steamer Electrical Operation Models Built Before 5/25/00 Old Style Boiler Controls VHX Series Steamer Electrical Operation Cooking Compartment Controls Boiler Base Controls TroubleshootingVHX Series Steamer Troubleshooting Symptom Possible Causes Adjustments Boiler blowdown solenoid valve clogged and not fully closing Boiler Base Procedures and Adjustments VHX Series Steamer NEW Style Controls only VHX24G, VHX24G5, MHB24G Condensed Spare Parts ListVHX Series Steamer Condensed Spare Parts List
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