Frymaster FMCFE Service & Parts Manual page 8

MASTER JET CF SERIES ATMOSPHERIC GAS FRYERS
1.1 Functional Description (cont.)
FREQUENTLY USED TEST POINTS FOR MODELS WITH INTERFACE BOARDS
12 VAC Power to Controller
24 VAC Power
24 VAC Power to Gas Valve
120 VAC Power
Probe Resistance*
** Disconnect 15-Pin harness from controller before testing probe circuit.
** See Probe Resistance Chart at end of chapter.
Four LEDs, arranged across the top of the boards and identified in the table below, are provided to
assist in troubleshooting.
Every board contains one heat relay (K3), and may contain two basket lift relays (K1 and K2). As
shipped from the factory, fryers with bell-crank basket lifts will have relays K1, K2, and K3. All
other factory-original fryers will have boards with only relay K3.
NOTE: The basket lift option is not available on MJCF Series fryers. The above diagnostic
tables are not applicable to user-supplied or KFC-1 computers.
THERMOSTATS AND TEMPERATURE PROBES
MJCF Series fryers equipped with thermostat controls have an adjustable controlling (operating)
thermostat. The temperature at which the thermostat opens and closes is adjusted by changing the
setting of the thermostat with an attached knob. When new, the Fenwal controlling thermostat is
sensitive to one-degree changes in temperature.
Fenwal thermostats are used in a number of Frymaster products. The thermostat for
the MJCF Series is 4 inches long. Do not use 3-inch Fenwal thermostats in MJCF
CHAPTER 1: SERVICE PROCEDURES
Meter
Test Setting
50 VAC Scale
50 VAC Scale
50 VAC Scale
250 VAC Scale
R x 1000 OHMS 2 and 3 of J1
MASTER JET SERIES INTERFACE BOARD
LED DIAGNOSTIC LIGHTS
GV Indicates 24 VAC to the gas valve
AL Indicates open Drain Safety Switch (if installed)
24V Indicates 24 VAC from transformer
COMP Indicates 12 VAC to computer
CAUTION
Series fryers.
Pins
1 and 3 of J2
24 VAC Terminals
6 on J1 and GROUND
7 and 12 of J1
1-3
Results
12-18
22-28
22-28
110-125
**