FloAire DIRECT FIRED MODULE - Manual (Page 20)

20
Components
The following image and list outlines the typical direct fired heater components and their functions.
1. Gas Inlet – Main gas supply connection
2. Motor Starter – Contactor with overload protection to start and protect motor.
3. Cooling Interlock Relay (Optional) – Energizes power to cooling circuit on call for cooling.
4. Inlet Gas Pressure Gauge – Inlet gas pressure should be read from here.
5. Combination Gas Valve - A combination of redundant solenoid valves, pilot valve and gas
regulator built into one unit.
6. Pilot Tubing – Pilot tube connection to combination gas valve.
7. Manual Reset High Temperature Limit – Safety device that prevents the heater from
overheating.
8. Modulating Amplifier - Regulates temperature by a modulating gas valve
9. Power Transformer
– Installed when motor voltage > 120V. Used to provide 120V service to
controls.
10. Circuit Breaker – Protects electrical components from high current spikes.
11. Terminal Strip – Central location to terminate control wiring. Should be used for troubleshooting.
12. Control Transformer – 120V primary; 24V secondary control transformer.
13. Low Pressure Airflow Probe – Measures profile pressure downstream of burner.
14. High Pressure Airflow Probe – Measures profile pressure upstream of burner.
15. Modulating Gas Valve – Modulates gas flow to burner to provide proper air temperature.
16. Manifold Gas Pressure Gauge – Manifold gas pressure should be read from here.
17. Flame Safety Control – Initiates and monitors flame.
18. Airflow Switch – A safety device insuring proper air flow during burner operation.
19. Ignition Transformer – Produces high voltage spark to ignite flame.
20. Intake Air Thermostat – De-energize heating circuit when intake air exceeds set-point.
21. Damper Actuator – Motor containing end switch that opens intake damper.
22. Manual Gas Shut-Off Valve Allows gas flow to burner to be shut off to leak test gas train
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