Vulcan-Hart MHB24G, VHX24G5 manual Water Refill After Initial Fill, Boiler Blowdown/drain

Page 48

VHX SERIES STEAMER - ELECTRICAL OPERATION

 

 

upper and lower set point limits. The

 

 

B.

Boiler connected to correct voltage

 

 

cycling pressure switch continues to

 

 

 

(120VAC).

 

 

energize and de-energize the heating

 

 

 

1) Power to cooking compartment

 

 

circuit to cycle the burner ON and OFF.

 

 

 

 

 

 

 

 

controls. See "COOKING

 

 

This sequence continues until one of the

 

 

 

 

 

 

COMPARTMENT CONTROLS" later

 

 

following occurs:

 

 

 

in this section.

 

 

1) Power switch is turned OFF.

 

 

C.

Boiler properly grounded (boiler and water

 

 

2) Boiler water level drops below the

 

 

 

level controls share a common ground)

 

 

 

 

 

 

 

 

 

LLCO probes for the main water level

 

D.

Gas and water supply valve(s) ON.

 

 

control (WLC) and the auxiliary low

 

E.

Main gas valve ON.

 

 

level control.

 

 

 

 

 

 

F.

Cycling pressure switch CLOSED.

 

 

3) Boiler pressurizes to 15 PSI, causing

 

 

 

 

 

 

 

 

 

the high limit pressure switch to open.

 

G.

High limit pressure switch CLOSED.

Water Refill (After Initial Fill)

 

 

H.

Cold water condenser (CWC) thermostat

1.

Water level drops below low level probe (LL).

 

 

OPEN.

 

 

I.

Automatic blowdown valve (A.B.D.) OPEN

 

A.

HL relay is energized.

 

 

 

 

 

 

and boiler empty.

 

 

 

 

 

 

 

 

 

 

1) HL-3 (N.O.) contacts close.

 

2. Turn power switch ON.

 

 

 

 

 

 

 

 

2) Fill solenoid is energized.

 

 

A.

Relay R4 energized and R4 contacts

 

 

 

 

 

 

 

 

 

3) HL LED comes ON.

 

 

 

(N.O.) CLOSE.

2. Water reaches LL (low level) probe.

 

 

B.

Power ON light (red) comes ON.

3. Water reaches high level probe.

 

 

C.

Blowdown solenoid valve is energized and

 

A.

HL relay is de-energized.

 

 

 

CLOSES.

 

 

 

D.

Auxiliary water level control is powered.

 

 

1) HL-3 (N.O.) contacts open.

 

 

 

 

 

 

 

1) Aux. LLCO N.O. contacts remain

 

 

2) Fill solenoid is de-energized.

 

 

 

 

 

 

 

 

OPEN (Aux. LLCO relay de-

 

 

 

 

 

 

 

 

 

 

3) HL LED goes out.

 

 

 

energized).

4. The water refill cycle will occur whenever the

 

E.

Low water level light (amber) comes ON.

 

water level is below the low level probe and will

 

NOTE: The low water indicator light will remain

 

not affect the operation of either the preheat or

 

 

 

ON and the safety circuit de-energized until the

 

cook cycle.

 

 

 

 

 

water level in the boiler reaches the auxiliary

 

 

 

 

 

 

 

Boiler Blowdown/drain

 

 

low level cut-off probes (aux. LLCO, minimum

1.

Power switch turned OFF.

 

 

level) for the aux. water level control, and the

 

 

manual reset switch is pressed.

 

 

 

 

 

 

 

 

A.

Automatic blowdown solenoid valve (N.O.)

 

F.

High pressure light (amber) comes ON.

 

 

is de-energized and valve opens to drain

 

 

 

 

NOTE: The high pressure indicator light will

 

 

the boiler.

 

 

 

B.

Power is removed from all components

 

 

remain ON and the safety circuit de-energized

 

 

 

until the manual reset button is pressed (high

 

 

except cold water condenser (CWC)

 

 

 

 

 

 

limit pressure switch must be closed).

 

 

thermostat and solenoid valve. The CWC

 

 

 

 

G.

Power is connected through the high limit

 

 

thermostat cycles as necessary to lower

 

 

 

the discharge temperature of the water

 

 

 

pressure switch contacts (N.C.) to one side

 

 

and condense steam going into the drain.

 

 

of the push button reset switch.

OLD STYLE CONTROLS - BOILER

 

 

H.

Water level control is powered (Low Level

This sequence of operation is written for boiler

 

 

 

Cut-off & Differential Control).

 

 

 

1) High level (HL) relay is energized, HL

bases with the old style boiler controls. See

 

 

 

"BOILER CONTROL STYLES" under "GENERAL".

 

 

contacts (N.O.) CLOSE

Refer to schematic diagram 5480.

 

 

 

a.

HL LED lights up.

 

 

 

 

 

 

 

 

Initial Fill And Preheat

 

 

 

b.

Fill solenoid is energized and

 

 

 

 

 

 

 

 

1.

Conditions.

 

 

 

 

water begins filling boiler (fill

 

A.

Power switch OFF.

 

 

 

 

time 4-11 min.).

 

 

 

 

 

 

F24700 (October 2001)

 

 

Page 48 of

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Page 47 Page 49
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Page 47 Page 49
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
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