Series Interface Board LED Diagnostic Lights

FREQUENTLY USED TEST POINTS FOR 45 SERIES INTERFACE BOARDS

	Meter
Test	Setting	Pins	Results
12 VAC Power to Controller	50 VAC Scale	1 and 3 of J2	12-18
24 VAC Power	50 VAC Scale	24 VAC Terminals	22-28
24 VAC Power to Gas Valve	50 VAC Scale	6 on J1 and GROUND	22-28
120 VAC Power	250 VAC Scale	7 and 12 of J1	110-125
Probe Resistance*	R x 1000 OHMS	2 and 3 of J1	**

*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.

45 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

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.

THERMOSTATS AND TEMPERATURE PROBES

Different types of thermostats are used in 45 Series fryers, depending on the fryers’ configuration.

Fryers equipped with Thermostat Controls have an adjustable controlling (operating) thermostat. The temperature at which the thermostat opens and closes is adjusted by physically changing the set- ting of the thermostat itself by means of an attached knob. When new, the Fenwal controlling ther- mostat used in 45 Series fryers is sensitive to one-degree changes in temperature.

CAUTION

Fenwal thermostats are used in a number of Frymaster products. The thermostat for the 45 Series is 4 inches long. Do not use 3-inch Fenwal thermostats in 45 Series fryers.

Fryers equipped with all other type controls have a temperature probe. In these units, the probe resistance varies directly with the temperature. That is, as the temperature 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). The temperatures are programmed by means of a keypad on the face of the controller.

All 45 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

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