Frymaster 2424G - Manual (Page 9)

24G SERIES FLATBOTTOM GAS FRYERS
CHAPTER 1: SERVICE PROCEDURES
1-3
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.
Control Options
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.