Greenheck DG / DGX Industrial Space Heating (464044 IOM) (Pre-2009) - Manual (Page 31)

Reference
1. Heating/Cooling Inlet Air Sensor (Optional) - Ductstat that automatically de-energizes burner when inlet air
temperature rises above set point, or shuts down cooling when temperature falls below set point.
2. Flame Safeguard - Monitors flame, shutsdown unit when unsafe conditions are detected.
3. High Limit - Shuts down burner for safety reasons when discharge temperature rises above set point.
4. Building Freeze Protection (Optional) - Shuts down the unit when the air falls below the set point and
remains below the set point for an adjustable period of time.
5. Heat/Cool Relay - Allows power to pass to Flame Safeguard or cooling unit.
6. Terminal Strip - 24 Volt power strip for control wiring.
7. Main Disconnect - On/Off switch, provides single point power connection to unit.
8. Grounding Lugs - Completes electrical circuit
9. Motor Starters - 24 Volt magnetic contacts for starting motors, comes standard with electronic overload,
may be provided with auxiliary contacts.
10. Spark Generator - Causes the spark rod to spark and ignite the pilot.
11. Amplifier - Controls modulating gas valve based on feedback from the discharge air sensor.
12. Low Voltage Transformer - Reduces voltage for the Maxitrol system.
13. Control Transformer - Provides 24 Volts for the controls and 120 Volts for the gas train.
14. Secondary Fuses - Provides proper fusing for all electrical components other than the motors.
15. Motor Fuses - Provides proper fusing for supply and exhaust fan motor(s).
Control Center Layout
R - 3
12 10 11
1
5 4
3 2
14
6
8
7 9
15 13
Figure 32.
Control Center