YFG255 SERIES GAS RETHERMALIZERS
CHAPTER 1: SERVICE PROCEDURES
1-2
A temperature probe monitors the temperature in the cookpot. 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 current to the
ignition module, resulting in closure of the gas valve.
Control Options
YFG255 Series gas rethermalizers are equipped with a factory preset temperature controller. These
are unique in that the components are wired directly to the controller and do not require an interface
board.
Temperature Probe
YFG255 rethermalizers are equipped with a temperature probe with resistance values that
correspond directly with the temperature. That is, as the temperature rises, so does resistance. See
the resistance table on page 1-20. Circuitry in the controller monitors the probe resistance and
controls burner firing when the resistance exceeds or falls below programmed temperatures
(setpoints).