Vulcan-Hart ML-126852, ML-126857, ML-126853, VHX24E5, MHB24E manual Cycling Pressure Switch Adjustment

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VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS

B.Verify Low Water light is lit (front control panel).

C.Verify 120VAC is on Aux LLCO COM, and 0 volt is on Aux LLCO N.O. contacts.

9.When water level reaches Aux LLCO probe as boiler continues to fill:

A.Verify Aux LLCO LED is lit on the auxiliary low water board.

B.Verify the green ready light is lit (front control panel).

C.Verify 120VAC is on the Aux LLCO common and normally open contacts of the auxiliary water level control board.

10.Open the ball valve on probe housing assembly. This will allow boiler to drain.

11.When water level is no longer visible in sight glass and is below LLCO probe; Aux LLCO circuit should activate.

A.Low water light turns on (front control panel).

B.Aux LLCO led turns off on the auxiliary low water board.

C.Press reset switch to verify lockout condition. Low water light should remain on.

D.If lockout condition does not occur, immediately turn power switch off.

1)Disconnect power to machine.

2)Replace auxiliary low level cut-off control and check for proper operation.

E.If lockout condition is ok, verify the auxiliary water level control circuit is functioning properly.

F.Close the ball valve on probe housing assembly and allow boiler to fill.

1)Verify low water light turns off (front control panel).

2)Press the reset switch and verify auxiliary contactors A & C are energized and boiler is heating.

3.Press reset switch and verify high pressure light turns off.

4.When green ready light comes on, press reset switch to begin heating (low water light turns off).

A.Allow boiler to fully pressurize. Cycling pressure switch opens and heating stops.

5.Turn one cooking compartment timer on to exhaust steam from boiler.

6.Monitor boiler pressure gauge for two complete cycles. Note pressure at which the heat comes on and goes off.

The heat should come on at 10 PSI and go off at 12 PSI.

A.If pressure readings differ, continue with procedure to adjust.

7.Two pressure adjustment screws extend through the top of switch cover. A clockwise rotation increases pressure; a counter- clockwise rotation decreases pressure.

A.Turn the adjustment screw above right side pointer to obtain the proper cut-out (off) pressure setting.

B.Turn the adjustment screw above the left side pointer to obtain the proper cut-in (on) pressure setting.

NOTE: The screw directly above the right side pointer adjusts cut-out (off) and cut-in (on) set points without changing the differential. The screw directly above the left side pointer adjusts cut-in (on) set point and changes the differential.

8.Monitor boiler pressure gauge for two complete cycles and note the pressure at which the heat comes on and goes off.

A.If pressures are correct, pressure switch is properly adjusted.

B.If pressures are not correct, repeat the adjustment for up to three attempts.

9.If the above adjustment cannot be obtained, install a replacement pressure switch and adjust pressure settings as outlined in this procedure.

CYCLING PRESSURE SWITCH

ADJUSTMENT

1.Access cycling pressure switch as outlined under PRESSURE SWITCH CONTROL BOX COMPONENTS in REMOVAL AND REPLACEMENT OF PARTS.

2.Turn power switch on (boiler begins to fill).

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F25154 (February 2004)

 

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Contents VHX24E Shown VHX Boiler Base Series High Efficiency Electric SteamerTable of Contents VHX Series Steamers General INSTALLATION, Operation Cleaning IntroductionModel Number of Pans PAN Depth PER Compartment Inches Boiler Pressure SpecificationsWater Conditioning Boiler Code DescriptionsSpecial ToolsElectrical StandardPressure Switch Control BOX Components Removal and Replacement of PartsMain Control BOX Components Left Side View Shown Water Level Gauge AssemblyHeating Elements Heating Elements Heating Element Mounting PlateRight Side View Shown Boiler AssemblyDescaler Cathodic Protector Handle Cooking Compartment DoorsRemoval GasketLatch Assembly Boiler Service Procedures and AdjustmentsWater Level Controls Test Water Level Probe Housing BlowdownMain Water Level Control Auxiliary Low level Cut-Off Control Cycling Pressure Switch Adjustment Boiler Fill and Cold Water Condenser Solenoid Valves High Limit Pressure Switch AdjustmentCold Water Condenser Thermostat Adjustment Heating Element Test Intake Shut-Off Valve Adjustment Steam FlowCooking Compartment Door Latch Adjustment Door Sealing AdjustmentCold Water Condenser Reset Switch ManualElectrical Operation Component FunctionBlowdown/Drain Compartment Pressure SwitchSteam Solenoid Valve Boiler Base Controls Component LocationsBoiler Base Controls Cooking Compartment Controls Low Level Cut-Off & Differential Control Water Level ControlsAuxiliary Low Level Cut-Off Relay Board Layout, Legend & Diagnostic Test PointsSchematic Initial Fill and Preheat Sequence of OperationBoiler Blowdown/drain Water Refill After Initial FillVHX Series Steamer Electrical Operation Schematics Cooking Compartment Controls Wiring Diagrams VHX Series Steamer Electrical Operation Heating Element Circuits Cooking Compartment Controls Symptom Possible Causes TroubleshootingBoiler Base Controls Symptom Possible Causes Symptom Possible Causes Cooking Compartment Controls VHX Series Steamer VHX Series Steamer VHX24E, VHX24E5, MHB24E Condensed Spare Parts ListPart Number Description
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