Vulcan-Hart MHB24G, VHX24G5 manual GAS Manifold Pressure Adjustment

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VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS

GAS MANIFOLD PRESSURE

ADJUSTMENT

WARNING: DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AT THE MAIN CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT BOX INDICATING THE CIRCUIT IS BEING SERVICED.

WARNING: SHUT OFF THE GAS SUPPLY BEFORE SERVICING THE UNIT.

1.Open the cabinet base door to access main gas valve.

2.Remove the manifold pressure tap plug from the outlet side of valve.

A.Install a hose barb adaptor and attach a gas pressure manometer.

3.Turn the gas supply and power switch ON.

A.Once the boiler fills, press the reset switch to start the ignition process.

NOTE: The reset switch can be pressed after the green ready light on the switch comes ON. This indicates the water level in the boiler is at the minimum operating level.

4.After the main burner lights, allow the boiler to reach operating pressure then compare the gas manometer pressure reading to the pressure chart near the end of this procedure.

A.If other appliances are connected to the same gas line, turn them all ON and check manometer pressure reading again. If the pressure drops ½ inch water column or more, then the gas supply needs to be checked by the gas line installer or the local gas company for adequate sizing.

NOTE: The gas supply line to the steamer should be a minimum of one inch diameter (ID).

B.If the pressure does not drop as described above but the manifold pressure still requires adjustment, proceed to step 5.

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

6.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	BURNER	LINE
	GAS TYPE
			MINIMUM
		MANIFOLD	MINIMUM	MAX
			RECOMMENDED	MAX
			RECOMMENDED

	Natural	3.0	7.0	14.0

	Propane	3.0	11.0
	Propane	3.0	11.0

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

F24700 (October 2001)		Page 36 of 68

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Contents VHX Boiler Base Series High Efficiency GAS Steamers VHX24G ShownTable of Contents VHX Series Steamers Installation Maintenance Cleaning IntroductionGeneral Boiler Control Styles Water Conditioning Specifications SystemWater Supply ElectricalTools Gas SupplyStandard SpecialSteamer Operation Cabinet Base BoilerCooking Compartment Controls VHX Series Steamers OperationBoiler Blowdown Steamer Shut OFF Component Function VHX Series Steamers Component FunctionBlowdown/Drain Ignition Control ModuleSteam Header Assembly Water LevelWater Inlet Valve manual Pressure Relief ValveCompartment Pressure Switch Steam Solenoid ValveManifold Pressure Gauge Steam Supply ManifoldRemoval and Replacement of Parts VHX Series Steamers Removal and Replacement of PartsComponent Locations Cabinet Base Boiler ControlsCabinet Base Boiler Controls Water Level Controls Main or Auxiliary Llco Relay BoardCooking Compartment Controls Water Level Gauge Assembly Pressure SwitchesBoiler Assembly Pilot GAS Valve Main GAS Valve Boiler Fill and Cold Water Condenser Solenoid ValvesBurner Head Assembly Complete Burner AssemblyHeat Exchanger VHX Series Steamers Removal and Replacement of Parts Cooking Compartment Doors RemovalGasket Latch Assembly HandleService Procedures and Adjustments Clean-OutBoiler InspectionWater Level Probe Housing Blowdown Descaler Cathodic ProtectorWater Level Controls TestAuxiliary Low level Cut-Off Control High Limit CyclingFill and Cold Water Solenoid Valves Small incrementsInline Water Strainer Cleaning Boiler BLOWDOWN/DRAIN Solenoid ValvePressure Switch Adjustment Main Burner Ignition ChecksGAS 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 Ignition Control Module Checks TerminalsSpark Verification Test Intake Shut-Off Valve Adjustment Steam Flow Door Sealing AdjustmentCooking Compartment Cooking Compartment DoorsDoor Latch Adjustment VHX Series Steamer Electrical OperationElectrical Operation Low Level Cut-Off & Differential ControlAuxiliary Low Level Cut-Off Board Layout and LED Legend LED LegendBoiler Operational Status LED Indicator Reset Engaged State CInitial Conditions State a Aux Water Level Satisfied State BAir Pressure Switch Satisfied State D K32 CloseK51 Close Burner ON, Boiler Heating to generate steam State ESequence of Operation NEW Style Controls BoilerInitial Fill and Preheat HL-LEDN9, N10, N11, N12, N13 go out N14, N16, N17 go outWater Refill After Initial Fill Boiler Blowdown/drainVHX Series Steamer Electrical Operation Cooking Compartment Controls This page Intentionally Left Blank Schematics Models Built After 5/25/00 New Style Boiler ControlsVHX 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 Troubleshooting VHX Series Steamer TroubleshootingBoiler Base Controls Symptom Possible Causes Adjustments Boiler blowdown solenoid valve clogged and not fully closing Boiler Base Procedures and Adjustments VHX Series Steamer Condensed Spare Parts List VHX Series Steamer Condensed Spare Parts ListNEW Style Controls only VHX24G, VHX24G5, MHB24G