Vulcan-Hart VL3GSS, VL3GMS Electric Models, Boiler Blowdown/drain, Initial Fill And Preheat

VL SERIES STEAMER - ELECTRICAL OPERATION

1)HL-3 opens.

2)Fill solenoid de-energized and water stops flowing into tank.

3)HL LED goes out.

4.The water refill cycle will occur whenever the water level is below the low level probe and will not affect the operation of either the preheat or cook cycle.

Boiler Blowdown/drain

1.Main power switch turned OFF.

A.Boiler blowdown sequence starts.

B.The blowdown solenoid valve (N.O.) is de- energized and valve opens to drain the boiler.

C.Power is removed from all components except cold water condenser (CWC) thermostat and solenoid valve. The CWC thermostat cycles as necessary to lower the discharge temperature of the water and condense steam going into the drain.

ELECTRIC MODELS

This sequence of operation is written for steamers with electro mechanical water level controls, Cal- Code boiler controls option and with Prevent cooking compartment controls. Refer to schematic diagram number 3941 for a boiler control schematic and 3962 for a schematic and wiring diagram on Prevent cooking compartment controls.

INITIAL FILL AND PREHEAT

1.Conditions.

A.Power switch OFF.

B.Manual reset switch OFF.

C.Cooking timers off.

D.Compartment power switches OFF.

E.Unit connected to correct voltage supply.

1)L1 to one side of the boiler fill solenoid valve; to one side of the main and auxiliary contactor(s); to one side of the power on light (red); to one side of the heat on light (amber); to one side of the timer motor; to one side of the cold water condenser solenoid valve; to one side of the blowdown solenoid valve; to terminal 1 on the auxiliary low level control then jumpers connect L1 to terminal 1 on the differential and low level controls; to the compartment controls.

2)L2 to the common terminal on the blowdown timer relay; to pin 4 on the boiler ON/OFF switch; to one side of the manual reset switch; to one side of the auxiliary switch(s) mounted on the side of the auxiliary contactor(s); to the compartment controls.

F.Unit properly grounded. (Boiler and water level control share a common ground)

G.Water supply valve on.

H.Control (cycling) pressure switch closed.

I.High limit pressure switch closed.

J.Cold water condenser (CWC) thermostat open.

K.Blowdown solenoid valve (drain) closed and boiler empty.

L.Compartment doors open.

2.Power switch turned ON. (located on boiler control box)

A.Power to terminal 2 on the differential water level control then jumpers connect to terminal 2 on both the low level cut-off and auxiliary low level cut-off water level controls.

B.Power switch indicator light (red) comes on.

C.Boiler fill solenoid valve is energized and boiler begins to fill.

NOTE: The safety circuit remains de-energized until the water level in the boiler reaches the low level cut-off probe (minimum level) for the auxiliary low level cut-off control and the manual reset switch is pressed. Also, until the water level in the boiler reaches the low level cut-off probe (minimum level) for the low level cut-off control, the low level cut-off control remains de-energized. The heating elements will not come on until the manual rest switch is pressed these conditions are satisfied.

3.Water level reaches LLCO (low water level cut- off) probe for the low level cut-off control and to the auxiliary LLCO probe for the auxiliary low level cut-off control.

A.Power to terminal 10 on the low level cut- off and on the auxiliary low level cut-off control is present. The internal contactor coil on the water level controls are then energized.

1)The normally open contacts on terminals 7 and 8 for both the main and auxiliary low level cut-off controls close.

2)The main heater contactor(s) are then energized.

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