25
SERVICE
Problem Probable Cause Corrective Action
Functional Description
The RF40 Series fryers contain a welded steel stainless frypot that is directly heated by gas
flames that are diffused evenly over its lower surface by ceramic deflectors (targets).
The flames originate from orifices in a U-shaped burner manifold positioned beneath the frypot.
The orifice diameters differ for natural and LP gas as indicated in the accompanying table.
Gas flow to the manifold is regulated by an electromechanical gas valve. This series of fryers
is equipped with a millivolt gas valve and all models use a pilot ignition system.
Pilot Ignition System
The pilot ignition system is made up of the pilot orifice, pilot hood, and a thermopile. The pilot
serves two purposes: light the burner and heat the thermopile. In operation, the thermopile is in
contact with the pilot flame and generates millivolts. The millivolt output passes through a
normally closed high-limit switch and energizes the gas valve pilot coil, which in turn opens
the pilot valve. If the pilot flame is extinguished, voltage is lost to the gas valve pilot coil and the
pilot valve closes
Thermostats
Fryers equipped with thermostat controls have an adjustable
controlling (operating) thermo-
stat. The temperature at which the thermostat opens and closes is adjusted by physically chang-
ing the setting of the thermostat itself by means of an attached knob. The Fenwal controlling
thermostat used in the RF40 Series fryers is sensitive to one-degree changes in temperature.
All RF40 Series fryers are equipped with a
high-limit thermostat. In the event that the fryer fails
to properly control the oil temperature, the high-limit thermostat prevents the fryer from over-
heating to the flash point. The high-limit thermostat acts as a normally closed power switch
that opens when exposed to temperatures above 425ºF to 450ºF (218ºC to 232ºC).
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Содержание Legend RD18
Страница 42: ...40 SERVICE...
