Sanyo CG1411, KGS1411 service manual Combustion Control, Safety Controls

8-1-3. Combustion Control

(1) Combustion

Combustion air is supplied into the burner for 20 seconds prior to ignition. The variable speed combustion air blower motor speed is sensed and controlled. After this pre-purge is competed, spark ignition is provided at the burner. Burner condition is monitored continuously during the burning period.

(2) Safety Controls

Following safety devices function to control the gas solenoid valve to shut off

●Flame Detection Circuit: Stops gas flow with flame sensor circuit

● Bimetal Thermostat:	Stops gas flow with bimetal thermostat at 221°F (105°C)
● Thermal Fuse:	Stops gas flow with thermal fuse at 302°F (150°C) — replaceable fuse
● Fuse-Control Circuit:	Protected by internal 3A and 5A device
	Supply
		Gas inlet

Exhaust

Joint

Refrigerant

heaterSolenoid valve 1

Solenoid

valve 2

Combination

gas valve

Ignition	Flame sensor
electrical rod	probe

Flame sensor

	Air	circuit
Combustion	Combustion
	blower fan
blower motor
	Ignition	Timer circuit
	circuit

Pre-purge circuit

Power supply

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