Raypak 0135A, 0195A, 0090A Servicing Procedures, Sequence of Operation, Start-upProcedures

SERVICING

PROCEDURES

General Location of Controls

Circulator

Manual Reset Limit

(in heater behind panel)

Pressure

Relief Valve

Field Wiring

Compartment

Temperature Sensor

Ignition Module

(Auto Ignition Only)

Transformer

Roll-Out Sensor

Gas Valve Fig.# 8195.3

Ignition Module

(Auto Ignition Only)

Fig. 8: General Location of Controls

Sequence of Operation

Intermittent Ignition Device (IID)

Heaters equipped with the IID system will automatical- ly light the pilot burner first and then the main burner, each time there is a call for heat from the tankstat. Whenever the tankstat 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 genera-

tor 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 lock- out. Lockout de-energizes the first main valve operator and closes the first main (pilot) valve in the gas con- trol, stopping pilot gas flow. The ignition control system must be reset by setting the tankstat below water tem- perature 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 genera- tor and energizes 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 burn- er flame.

When the tankstat is satisfied, the valve operators are de-energized shutting off the pilot and main burners, and also the circulator.

Start-up Procedures

Filling the System

Fill system with water. Purge all air from the system using purge valve sequence. After system is purged of air, lower system pressure. Flush system before put- ting into operation to ensure that foreign material does not damage pump seals.

Checking the Circulator

Before lighting the heater and after system is filled, make sure that circulator is operating properly. Manual gas valve should be off.

NOTE: Circulator motor supplied with the heater does not require lubrication.

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