Thermostats - Frymaster 47 SERIES Installation, Operation, Service, And Parts Manual

The following table identifies the meaning as-
sociated with each of the LEDs arranged
across the top of the interface board. NOTE:
For full vat units, ignore the left-side LEDs.
P/N 806-5857 INTERFACE BOARD
LED DIAGNOSTIC LIGHTS
AL Indicates ignition module lockout
MV Indicates 24 VAC to gas main valve
PV Indicates 24 VAC to pilot valve
CMP Indicates 12 VAC from transformer
24V Indicates 24 VAC from transformer
PWR Indicates 24 VAC to ignition module
IFB 806-3398. This standard interface board
is used in a number of fryer types besides the
47 Series. In the 47 Series, it is used in pilot
ignition (millivolt) systems only. The infor-
mation contained in this section applies
only to 47 Series applications.
The board contains two heat relays (K1 and
K2), and two basket lift relays (K3 and K5).
Relay K4 has no function in 47 Series appli-
cations. NOTE: On factory-original units not
equipped with basket lifts, the board will have
no basket lift relays installed. Like the 806-
5857 interface board, LEDs are provided to
assist in troubleshooting.
P/N 806-3398 INTERFACE BOARD
LED DIAGNOSTIC LIGHTS
12V Indicates 12 V A C f rom transf ormer
24V Indicates 24 V A C f rom transf ormer
GV Indicates 24 V A C to gas valve
PWR Indicates 24 V A C to PWR via K1 (L) or K2 (R or F)
AL Indicates open Drain Saf ety Sw itch (if installed)
AIR No f unction in 47 Series applications

THERMOSTATS

Different types of thermostats are used in 47
Series fryers, depending on the fryers' con-
figuration.
47 SERIES GAS FRYERS
CHAPTER 7: SERVICE PROCEDURES
7-7
Fryers equipped with Thermostat Controls
have an adjustable controlling thermostat.
The temperature at which the thermostat opens
and closes is adjusted by physically changing
the setting of the thermostat itself by means of
an attached knob. The Fenwal controlling
thermostat used in the 47 Series fryers is sen-
sitive to one-degree changes in temperature.
CAUTION
Fenwal thermostats are used in a
number of Frymaster™ products. The
thermostat for the 47 Series is 4 inches
long. Do not use 3-inch Fenwal
thermostats in 47 Series fryers.
Fryers equipped with all other type controls
have a temperature probe. In this type ther-
mostat, the probe resistance varies directly
with the temperature. That is, as the tem-
perature rises, so does resistance at a rate of
approximately 2 ohms for every 1º (F or C).
Circuitry in the controller monitors the probe
resistance and controls burner firing when the
resistance exceeds or falls below programmed
temperatures (setpoints).
are programmed by means of a keypad on the
face of the controller.
All 47 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 overheating 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). The different types of thermostats
have different part numbers for CE and Non-
CE configured models, and are not inter-
changeable.
The temperatures