Vulcan-Hart ML-126852, ML-126857 Electrical Operation, Component Function, Reset Switch Manual

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VHX SERIES STEAMER - ELECTRICAL OPERATION

ELECTRICAL OPERATION

COMPONENT FUNCTION

CABINET BASE BOILER CONTROLS

Power Switch . . . . . . . . . . . . . . . .

Reset Switch (Manual) . . . . . . . . .

Boiler Fill Valve . . . . . . . . . . . . . . .

Cold Water Condenser

Valve . . . . . . . . . . . . . . . . . . . . . . .

Cold Water Condenser

Cycling Thermostat . . . . . . . . . . .

Cycling Pressure Switch . . . . . . .

High Limit Pressure Switch . . . . .

Main Water Level Control . . . . . .

Auxiliary Water Level Control . . .

Relay Board . . . . . . . . . . . . . . . . . .

Controls 120VAC to the boiler control circuit.

Resets the low water level safety circuit on initial startup or the occurrence of a low water condition. Also, resets the high pressure level safety circuit on initial startup or the occurrence of a high pressure condition which allows heating to start.

Allows water flow to the boiler when energized thru HL-3 contacts on the water level control.

Allows cold water to spray thru a nozzle inside the condenser drain box to condense steam and cool the hot water before discharging into the drain.

Regulates cold water spray inside the condenser drain box during a cooking cycle or boiler blowdown/drain.

Regulates boiler pressure between cut-out (off) and cut-in (on) pressure settings of switch.

Prevents boiler from reaching pressures above 15 PSI by removing power from heating circuit. The high limit automatically resets at approximately 12 psi (green ready light on).

A dual function control that allows water to fill and maintain the proper level in the boiler, providing differential level control; and removes power from heating circuit if water level drops too low, providing low level cut-off protection. The control uses three different probe lengths to monitor water level (high level HL, low level LL, low level cut-off LLCO).

A back up to the low level cut-off on the main water level control. Protects boiler and heating system components from a low water cut-off condition by opening the 120VAC voltage path to the heating circuit. The control uses a single probe to monitor water level (auxiliary low level cut-off Aux LLCO).

Provides a centralized location for wire harness connections and power transfer thru board relays (K1-K4) to the steamer controls. Also, provides voltage test points (T1-T7) for verifying voltage to relay coils, N.O. relay contacts closed, control panel lights and auxiliary contactor coils.

NOTE: The relay’s below are mounted on the relay board and are individually replaceable.

K1 Relay

Energized when water level reaches the Aux LLCO probe (water level

 

condition satisfied).

K2 Relay

Energized when high limit pressure switch is closed (high limit pressure

 

condition satisfied). When K1 & K2 are energized, ready light (green) will be

 

on.

K3 Relay

Energized when K1(2) N.O. contacts close and reset switch is activated.

 

When K3 is energized, K3(2) N.O. contacts close and low water light turns

 

off.

K4 Relay

Energized when K2(2) N.O. contacts are closed and reset switch is

 

activated. When K4 is energized, K4(2) N.O. contacts close and high

 

pressure light turns off. When K3 and K4 are energized, power is supplied to

 

auxiliary contactors A & C.

F25154 (February 2004)

 

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Contents VHX Boiler Base Series High Efficiency Electric Steamer VHX24E ShownTable of Contents VHX Series Steamers INSTALLATION, Operation Cleaning Introduction GeneralModel Number of Pans PAN Depth PER Compartment Inches Specifications Water ConditioningBoiler Code Descriptions Boiler PressureTools ElectricalStandard SpecialRemoval and Replacement of Parts Pressure Switch Control BOX ComponentsMain Control BOX Components Water Level Gauge Assembly Left Side View ShownHeating Elements Heating Element Mounting Plate Heating ElementsBoiler Assembly Right Side View ShownDescaler Cathodic Protector Cooking Compartment Doors RemovalGasket HandleLatch Assembly Service Procedures and Adjustments BoilerWater Level Probe Housing Blowdown Water Level Controls TestMain Water Level Control Auxiliary Low level Cut-Off Control Cycling Pressure Switch Adjustment High Limit Pressure Switch Adjustment Boiler Fill and Cold Water Condenser Solenoid ValvesCold Water Condenser Thermostat Adjustment Intake Shut-Off Valve Adjustment Steam Flow Heating Element TestCooking Compartment Door Sealing Adjustment Door Latch AdjustmentReset Switch Manual Electrical OperationComponent Function Cold Water CondenserCompartment Pressure Switch Blowdown/DrainSteam Solenoid Valve Component Locations Boiler Base ControlsBoiler Base Controls Cooking Compartment Controls Water Level Controls Low Level Cut-Off & Differential ControlAuxiliary Low Level Cut-Off Layout, Legend & Diagnostic Test Points Relay BoardSchematic Sequence of Operation Initial Fill and PreheatWater Refill After Initial Fill Boiler Blowdown/drainVHX Series Steamer Electrical Operation Schematics Cooking Compartment Controls Wiring Diagrams VHX Series Steamer Electrical Operation Heating Element Circuits Cooking Compartment Controls Troubleshooting Symptom Possible CausesBoiler Base Controls Symptom Possible Causes Symptom Possible Causes Cooking Compartment Controls VHX Series Steamer VHX Series Steamer Condensed Spare Parts List VHX24E, VHX24E5, MHB24EPart Number Description