Vulcan-Hart VHX24G5, MHB24G manual Pressure Readings Inches W.C

Page 35

VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS

4.After the main burner lights, allow the boiler to reach operating pressure then turn the ON/OFF knob for the main gas valve to OFF.

5.Restart the ignition sequence by "rapidly" turning the power switch OFF then back ON. A rapid switching is needed to keep the boiler from starting automatic blowdown.

A.Press the reset switch to start the ignition process.

6.After the pilot burner lights, compare the manometer pressure reading to the pressure chart near the end of this procedure.

NOTE: The pilot gas valve operates on a time delay circuit and will only be energized for approximately 15 seconds to light the main burner then shut OFF. The pilot pressure reading must be taken while the pilot valve is energized within this time interval. After the main burner ignition time expires, the ignition control module will sense there is no flame present and will then try to re-establish a flame to light the main burner. This cycle will continue to repeat until the main gas valve is turned back ON.

A.If the pressure is not correct, proceed to step 7 to adjust.

B.If the pressure is correct, turn the power switch OFF, replace the adjustment screw cap and pilot pressure plug tap to the gas valve. Turn the knob on the main gas valve back to ON.

7.Remove the adjustment screw cap to access the pressure adjustment screw.

8.With the burner lit, set the pressure as outlined below.

A.To increase pressure, turn the screw clockwise.

B.To decrease pressure, turn the screw counterclockwise.

NOTE: Accurate gas pressure adjustments can only be made with the gas ON and the burner lit.

		PRESSURE READINGS (INCHES W.C.)

	GAS TYPE	PILOT	LINE
	GAS TYPE
			MINIMUM
		MANIFOLD	MINIMUM	MAX
			RECOMMENDED	MAX
			RECOMMENDED

	Natural	3.5	7.0	14.0

	Propane	3.5	11.0
	Propane	3.5	11.0

NOTE: If the incoming line pressure is less than the minimum recommended, then the manifold pressure can not be set correctly.

9.Once the correct pressure has been set, turn the gas supply and power switch OFF. Replace the adjustment screw cap and pilot pressure plug tap on the valve.

10.Turn the knob on the main gas valve to ON, the gas supply ON and check for proper operation.

Page 35 of 68		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 Electrical Water Conditioning SpecificationsSystem Water SupplySpecial ToolsGas Supply StandardVHX Series Steamers Operation Steamer OperationCabinet Base Boiler Cooking Compartment ControlsBoiler Blowdown Steamer Shut OFF Ignition Control Module Component FunctionVHX Series Steamers Component Function Blowdown/DrainPressure Relief Valve Steam Header AssemblyWater Level Water Inlet Valve manualSteam Supply Manifold Compartment Pressure SwitchSteam Solenoid Valve Manifold Pressure GaugeCabinet Base Boiler Controls Removal and Replacement of PartsVHX Series Steamers Removal and Replacement of Parts Component LocationsCabinet 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 AssemblyInspection Service Procedures and AdjustmentsClean-Out BoilerDescaler 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 Cooking Compartment Doors Intake Shut-Off Valve Adjustment Steam FlowDoor Sealing Adjustment Cooking CompartmentVHX Series Steamer Electrical Operation Door Latch AdjustmentLow Level Cut-Off & Differential Control Electrical OperationAuxiliary Low Level Cut-Off LED Legend Board Layout and LED LegendAux Water Level Satisfied State B Boiler Operational Status LED IndicatorReset Engaged State C Initial Conditions State aBurner ON, Boiler Heating to generate steam State E Air Pressure Switch Satisfied State DK32 Close K51 CloseHL-LED Sequence of OperationNEW Style Controls Boiler Initial Fill and PreheatN14, 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