Single Or 2 Stage; Staged - Greenheck IG Installation, Operation And Maintenance Manual

Reference - Model IGX

(Single or 2 Stage)

5 5
1 2
6 3
4
7
9
8
This is a typical furnace 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.
1. Low Voltage Transformer - Provides low voltage
to the ignition controller.
2. Low Voltage Transformer - Provides low voltage
to the ignition stage controller.
3. Control Terminal Block - Provides wiring access
to heat controls.
4. Control Terminal Block - Provides wiring access
to heat/combustion blower controls.
5. Stage Controller - Provides single or two
stages of furnace control based on discharge air
temperature set point.
6. Ignition Controller - Controls the ignition of the
furnace. Maintains safe operation of the furnace.
7. Combustion Blower Contact - Passes power to
the combustion blower.
8. Airflow Switch - Monitors the airflow inside the
heat exchanger to ensure proper combustion
airflow.
9. High Fire Relay - Allows furnace to ignite on high
fire.
68
Model IG / IGX Make-Up Air
Manifold
Gas Pressure
Test Port
3/4 inch

Staged

Gas Supply
Gas Valve
Connection
NOTE
Reference - Model IGX
(8:1 Staged)
8 9
5
7
1 2
7 3
4
6
10
11
This is a typical furnace 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.
1. Low Voltage Transformer - Provides low voltage
to the staged controller.
2. Low Voltage Transformer - Provides low voltage
to the ignition controllers.
3. Control Terminal Block - Provides wiring access
to controls.
4. Control Terminal Block - Provides wiring access
to controls.
5. Input Converter - Receives and converts signal
from Building Management Systems (BMS).
6. Stage Controller - Provides eight stages of
control based on discharge temperature set point.
7. Ignition Controllers - Controls the ignition of the
furnace. Maintains safe operation of the furnace.
8. Contactor Relay - Allows power to pass to the
combustion blower contact.
9. Air Proving Switch Relay - Functions as a relay
for the pressure switch.
10. Combustion Blower Contact - Passes power to
the combustion blower.
11. Airflow Switch - Monitors the airflow inside the
heat exchanger.
Small Manifold
Gas Pressure
Test Port
Large Manifold
Staged
Gas Valve
Gas Pressure
Test Port
3/4 inch Gas Supply
Connection
NOTE
®