Greenheck IG / IGX (464104 IOM) (Pre-2009) - Manual (Page 85)

85
Reference - Model IG (4:1 Modulating)
Manifold
Gas Pressure
Test Port
3 ⁄
4
inch Gas Supply
Connection
Staged Gas
Valve
Modulating
Gas Valve
Reference
1 2
11 12 13 14 10 8 9
3 4 5 6 7
1. Building Freeze Protection - Prevents the discharge of cold air into the building.
2. Input Converter - Receives and converts signal from building management system.
3. Evaporative Cooling Controls (Optional) - Controls the evaporative cooler.
4. Fusing - Provides 24 VAC fusing for controls and fusing for the combustion blower.
5. Main Disconnect - Provides single point power connection to the unit.
6. Modulation Controller - Provides 4:1 modulating turndown control of the furnace.
7. Relays - Call for heat and pressure switch relays.
8. Motor Starter(s) - Magnetic contact(s) for starting motor(s). Comes standard with electronic overload,
auxiliary contact(s) optional.
9. Ignition Controller - Controls the ignition of the furnace. Maintains safe operation of the furnace.
10. Terminal Strip - Provides easy, number coded wiring of the control.
11. Main Transformer - Provides 24 VAC for controls.
12. Dirty Filter Switch - Switch trips when filters are dirty and pressure loss is higher than set point.
13. Amplifier - Controls the modulating valve based on input from the temperature selector and the
discharge air sensor.
14. Airflow Switches - Monitors the airflow inside the heat exchanger.
15. Grounding Lugs (not shown) - Completes electrical circuit.
NOTE!
This is a typical blower control center, the control center in your unit may be different. Reference the
ladder diagram on the inside of the control center door for a unit specific wiring diagram.