Vulcan-Hart 136647, Service Manual

GRA SERIES GAS FRYERS - ELECTRICAL OPERATION

ELECTRICAL OPERATION

COMPONENT FUNCTION

FRYER CONTROLS

Cooking Control

. . . . . . . . . . . . . . Monitors and evaluates input signals to the control: Activates heat output

signal to maintain shortening temperature; and activates filter output signal
to power the fill solenoid valve.

Transformer . . . . . . . . . . . . . . . . .

Supplies 24VAC to the cooking control ignition control module. Transformer
is energized when power switch is turned on.

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

Supplies power to control circuit for fryer operation and filtering.

Melt  Select  Switch . . . . . . . . . . . .

Controls burner operation based on type of shortening being used (liquid/
solid).

Gas  Combination  Valve . . . . . . . .

Allows gas flow to the pilot when pilot valve coil is energized; and gas flow to
the burners when main valve coil is energized. Also, regulates the gas
manifold pressure.

High  Limit  Thermostat . . . . . . . . .

Prevents the shortening from reaching temperatures over 450

E

F (auto reset

@ 415°F, normal operation resumes when temperature falls below this
point).

Temperature  Probe . . . . . . . . . . .

Senses temperature of shortening. Converts the temperature into a
resistance which is monitored by the cooking control. The probe is an RTD
(resistance temperature detector) of the Thermistor type. As temperature
increases the resistance value decreases.

Ignition Control Module . . . . . . . .

Controls and monitors gas pilot ignition. Energizes pilot valve coil on the
combination control valve and generates spark for pilot ignition. Monitors the
presence of a flame and supplies an ignition status input signal to the
cooking control.

Ignitor/Flame  Sense . . . . . . . . . . .

Ignites the gas pilot and senses the presence of a flame. The flame
presence generates a micro-amp flame sense current that is rectified to the
ignition control module.

Drain Valve Interlock
Switch  (DVI) . . . . . . . . . . . . . . . . .

A magnetic reed switch mounted on the manual drain valve that supplies a
drain valve position signal (open/closed) to the cooking control. When drain
valve is open, the drain interlock input to the control is removed (magnetic
reed switch contacts open). This prevents gas burners from coming on with
the fry tank empty.

F25377 (March 2010)

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