Cleveland Range KGT-12-T, KGT-6-T manual Operating Sequences, Solid State Control Sequence

OPERATING SEQUENCES

1.	Turn On-Off Switch/	*	14 volt transformer is energized and powers solid state control system.
	Temperature Control Knob "ON"	*	Temperature knob is turned up and control box calls for heat.
		*	Relay (RY-1) closes and powers 24 volt transformer.
		*	Ignition control box is powered.
3.	Ignitor Sparks	*	Gas valve is energized.
		*	Ignitor sparks and ignition occurs.
4.	Temperature Reached	*	Solid state controls senses temperature reached.
		*	Relay (RY-1) opens and 24 volt transformer loses power.
		*	Ignition control box is turned off.
		*	Gas valve closes.
5.	Maintaining Temperature	*	Solid state controls senses temperature drop.
		*	Relay (RY-1) closes and powers 24 volt transformer.
		*	Ignitor control box is powered.
		*	Steps three and four are repeated.

SOLID STATE CONTROL SEQUENCE

Our solid state controls consist of the following components.

On-Off Switch/	* Provides or interrupts electrical power to the control system.
Temperature	* Rotate to change resistance from 0 to 50,000 ohms. This resistance is
Control Knob	compared to the resistance on the thermistor using a voltage comparator
(Potentiometer)	circuit inside the control box.
	* If the resistance is lower than the thermistor resistance then the control box will
	provide 14v dc to pin #8. The green indicator light illuminates and the control
	relay (RY-1) is energized closed to provide power to the heating system.
Control Box	* Analyzes inputs from water level probe, tilt switch, potentiometer, thermistor.
	* Energizes control relay (RY-1)
Water Level Probe	* Senses water in jacket.
Tilt Switch	* When kettle is in upright position tilt switch is closed to complete circuit
	between pin #8, the relay (RY-1) and green indicator light.
Thermistor	* The thermistor resistance decreases as temperature increases. When the
	thermistor resistance equals the potentiometer then 14v dc is removed from
	pin #8. The control relay (RY-1) returns to the normally open position.
Green LED Light	Indicates that the control box is calling for heat. Pin #8 powered.
Red LED Light	Indicates that the water level probe is not immersed in water. Not enough water
	in the jacket or kettle tilted.
Relay (RY-1)	When energized allows the heating circuit to function. Electric elements or gas
	burner system.
NOTES:

*A ground loop circuit must be established between kettle body, water in jacket, water level probe and control box. If this loop is present, it indicates that there is sufficient water in the kettle for safe operation.

*If there is not sufficient water in the jacket then the loop is broken and the control box will prevent 14v DC from being supplied to pin #8. The control relay (RY-1) will remain (or return) to the normally open position and the unit cannot heat. The red LED light will be illuminated.