Frymaster H50 Series manual Interface Boards

the other leg of the heat relay coils, which then close electronic switches in the 24 VAC circuit to provide current to the ignition module. Circuitry in the ignition module sends 24 VAC to the gas valve via a normally closed high-limit switch (and, in fryers with built-in filtration systems, a normally closed drain safety switch). Simultaneously, the module causes the ignitor to spark for 4 seconds to light the burner. A flame sensor verifies the burner ignition by measuring the flow of microamps through the flame. If the burner does not light (or is extinguished), current to the ignition module is cut, the gas valve closes, and the ignition module “locks out” until the power switch is turned off and then back on. A probe monitors the temperature in the frypot. When the programmed setpoint temperature is reached, resistance in the probe causes the heat cycle circuitry in the controller to cut off current flow through the heat relay. This in turn cuts off the 24 VAC to the ignition module, causing the gas valve to close.

INTERFACE BOARDS

All fryers in this series have an interface board located in the component box located behind the control panel. The interface board provides a link between the controller/computer and the fryer’s individual components without requiring excessive wiring, and allows the controller to execute commands from one central point. The H50 Series of fryers has been in production since 1983. Consequently, servicers are likely to encounter three different interface board designs. Although the boards differ slightly in appearance, basic functioning and electrical connections are the same from one to another. In the earlier design 806-3398 interface board (used between June 1996 and July 1999), the diagnostic LEDs are arrayed in a row across the bottom of the board as shown in the left- hand illustration below. In later design 806-3398 interface boards (and in the 106-0396 interface boards that replaced them in current production fryers), the LEDs (labeled D1 though D7) are scattered around the board as shown in the right-hand illustration. The primary difference between the earlier design boards and the later design boards is the combining of the separate blower motor relay (K4) and the heat relays (K1 and K2) into a pair of replaceable relays (K2 and K3) in the latter. Also, the 106-0386 interface board has an additional fuse located in the upper right hand corner. Prior to June 1996, a board with replaceable relays very similar in appearance to the 106-0386 board was used. It is distinguished from the 106-0386 board by the absence of fuses.

NOTE: Although the printing on many boards indicates 2 Amp fuses, 3 Amp fuses (P/N 807-3843) must be used.

	SOUND										GND
	1				1	4	7	10	13
GND	2			J2	2	5	8	11	14
	3				3	6	9	12	15
3	6	9	12						3	6	9	12
2	5	8	11						2	5	8	11

		SOUND			J2									GND
		1							13
					1	4	7	10
		2										F2	Ignition		D7
GND					2	5	8	11	14	D6		2 AMP Module
		3			3	6	9	12	15						AIR
										12V
	3	6	9	12							3	6	9	12
					This Fuse is NOT
J1	2	5	8	11							2	5	8	11	J3
					present on 806-3398 IFB.

J1

1 4 7 10

J3

1 4 7 10

1 4 7 10 1 4 7 10

GND V2D

PWR AD AS V2S

K3 K4

BLOWER

MOTOR

RELAY

HEAT

RELAY

K1 K2

K5

	GND
	V1D
	PWR
	ALR
HEAT	V1S
RELAY

GND V2D

PWR

AD

AS

V2S

D1	K1
GV

HEAT

RELAY

D2 PWR AND

BLOWER

MOTOR

K4

D3

24V

HEAT

RELAY

AND

BLOWER

MOTOR

	D5
Blower	GV
Motor	GND
2 Amp

	V1D
	PWR
	ALR
D4	V1S
	PWR

1	2	6	3	4	5
GND	GV PWR AL 12V AIR 24V			AL PWR GV GND

GND	RELAY
	K2

RELAY

K3

GND

EARLIER DESIGN INTERFACE BOARD P/N 806-3398

LATER DESIGN INTERFACE BOARDS P/N 806-3398 and 106-0386

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