Control Options

24G SERIES FLATBOTTOM GAS FRYERS CHAPTER 1: SERVICE PROCEDURES

via transformer to 24 VAC before entering the ignition module. If resistance in the temperature probe indicates the temperature in the frypot is below 150°F (66°C), the current flows through a melt cycle circuit where a switch alternately closes for approximately 4 seconds and opens for approximately 20 seconds. If the temperature is 150°F (66°C) or above, the current flows through a heat circuit, bypassing the timer switch. In either case, current is supplied to the other leg of the heat relay coil, which then closes an electronic switch in the 24 VAC circuit to provide current to the ignition module.

Circuitry in the ignition module sends 24 VAC current to the gas valve via a normally closed high- limit switch and a drain safety switch. Simultaneously, the module causes the ignitor to spark for up to 11 seconds to light the burner flame. A flame sensor verifies that the burner is lit by measuring the flow of microamps through the flame. If the burner does not light (or is extinguished), current to the ignition module is interrupted, preventing the main valve from opening, and the ignition module "locks out" until the power switch is turned "OFF", then back "ON".

A temperature probe monitors the temperature in the frypot. When the programmed setpoint temperature is reached, resistance in the probe causes the heat cycle circuitry in the controller to interrupt current flow through the heat relay. This in turn interrupts the 24 VAC to the ignition module, resulting in closure of the gas valve.

24G Series Flatbottom gas fryers are equipped with Thermatron temperature controller. The fryer is turned on and off by means of a rocker switch and the temperature is set by adjusting a potentiometer. The Thermatron board is located in the wireway box behind the control panel, or in a component box inside the cabinet (depending on fryer configuration).

The Thermatron temperature controller operates by comparing resistance between the potentiometer setting and the temperature probe. If the resistance values don’t match, an on-board relay energizes, sending voltage to the gas valve, which supplies fuel to the burners. When the resistance values are equal, the on-board relay de-energizes, interrupting voltage to the gas valve, which stops the fuel flow.

Depending on the system configuration and destination, 24VAC, 115VAC or 208/230VAC controller boards are used.

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