Vulcan-Hart ML-126852, ML-126857 Electrical Operation, Component Function, Reset Switch Manual

VHX SERIES STEAMER - ELECTRICAL OPERATION

ELECTRICAL OPERATION

COMPONENT FUNCTION

CABINET BASE BOILER CONTROLS

Power Switch . . . . . . . . . . . . . . . .

Reset Switch (Manual) . . . . . . . . .

Boiler Fill Valve . . . . . . . . . . . . . . .

Cold Water Condenser

Valve . . . . . . . . . . . . . . . . . . . . . . .

Cold Water Condenser

Cycling Thermostat . . . . . . . . . . .

Cycling Pressure Switch . . . . . . .

High Limit Pressure Switch . . . . .

Main Water Level Control . . . . . .

Auxiliary Water Level Control . . .

Relay Board . . . . . . . . . . . . . . . . . .

Controls 120VAC to the boiler control circuit.

Resets the low water level safety circuit on initial startup or the occurrence of a low water condition. Also, resets the high pressure level safety circuit on initial startup or the occurrence of a high pressure condition which allows heating to start.

Allows water flow to the boiler when energized thru HL-3 contacts on the water level control.

Allows cold water to spray thru a nozzle inside the condenser drain box to condense steam and cool the hot water before discharging into the drain.

Regulates cold water spray inside the condenser drain box during a cooking cycle or boiler blowdown/drain.

Regulates boiler pressure between cut-out (off) and cut-in (on) pressure settings of switch.

Prevents boiler from reaching pressures above 15 PSI by removing power from heating circuit. The high limit automatically resets at approximately 12 psi (green ready light on).

A dual function control that allows water to fill and maintain the proper level in the boiler, providing differential level control; and removes power from heating circuit if water level drops too low, providing low level cut-off protection. The control uses three different probe lengths to monitor water level (high level HL, low level LL, low level cut-off LLCO).

A back up to the low level cut-off on the main water level control. Protects boiler and heating system components from a low water cut-off condition by opening the 120VAC voltage path to the heating circuit. The control uses a single probe to monitor water level (auxiliary low level cut-off Aux LLCO).

Provides a centralized location for wire harness connections and power transfer thru board relays (K1-K4) to the steamer controls. Also, provides voltage test points (T1-T7) for verifying voltage to relay coils, N.O. relay contacts closed, control panel lights and auxiliary contactor coils.

NOTE: The relay’s below are mounted on the relay board and are individually replaceable.

K1 Relay	Energized when water level reaches the Aux LLCO probe (water level
	condition satisfied).
K2 Relay	Energized when high limit pressure switch is closed (high limit pressure
	condition satisfied). When K1 & K2 are energized, ready light (green) will be
	on.
K3 Relay	Energized when K1(2) N.O. contacts close and reset switch is activated.
	When K3 is energized, K3(2) N.O. contacts close and low water light turns
	off.
K4 Relay	Energized when K2(2) N.O. contacts are closed and reset switch is
	activated. When K4 is energized, K4(2) N.O. contacts close and high
	pressure light turns off. When K3 and K4 are energized, power is supplied to
	auxiliary contactors A & C.

F25154 (February 2004) Page 24 of 48