Raypak 135A, 195A, 090A Servicing Procedures, General Location Of Controls, Sequence Of Operation

4. SERVICING PROCEDURES	Circulator
GENERAL LOCATION OF CONTROLS
CONTROL BOX COMPONENT LOCATIONS

Manual Reset Limit

Pressure

Relief Valve

Ignition Module (Auto Ignition Only)

Field Wiring

Compartment

Temperature Sensor Ignition Module

	(Auto Ignition Only)
	Transformer
SEQUENCE OF OPERATION	Roll-Out Sensor
	Gas Valve	Fig.# 8195.3

INTERMITTENT IGNITION DEVICE (IID)

Heaters equipped with the IID system will automati- cally light the pilot burner first and then the main burner, each time there is a call for heat from the tankstat. Whenever the tankstat is calling for heat, the circulator supplied with the heater, will be energized and should be running. The ignition control module will also be energized to initiate the pilot ignition by opening the first main valve (pilot). At the same time, the electronic spark generator in the module produces a high voltage spark pulse output that lights the pilot burner. If the pilot burner does not light, the module will not energize the second main valve and the burners will not light. Ignition spark continues only until the timed trial for ignition period ends. Then, the module goes into safety shutdown or lockout. Lockout de-energizes the first main valve operator and closes the first main (pilot) valve in the gas control, stopping pilot gas flow. The ignition control system must be reset by setting the tankstat below water temperature for one minute or by turning off power to the module for one minute. When the pilot flame is established, flame rectification circuit is completed between the sensor and burner ground. The flame sensing circuit in the module detects the flame current, shuts off the spark generator and ener- gizes the second main valve operator which opens the second main valve. This allows gas to flow to the burners where it is ignited by the pilot burner flame. When the tankstat is satisfied, the valve operators are de-energized shutting off the pilot and main burners, and also the circulator.

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