Setpoints
The setpoints and related data include the following items:
- Power exhaust fan type (ExFType) modulating damper
- Exhaust damper position fan on (ExDmpPosFanOn)
- Exhaust damper position fan off (ExDmpPosFanOff)
- Building pressure setpoint (Bldg-Sp)
- Building pressure reading (Bldg-Pres)
Inputs
The input for modulating power exhaust is: 0 to 5 VDC from building pressure sensor to terminals BLDG PRES.
Outputs
The outputs include the following items:
- 2 to 10 VDC from EX VFD for exhaust discharge damper modulation.
- 24 VAC from EX-FAN to energize exhaust fan
Operation
If the building pressure is above the building pressure setpoint, the exhaust damper output (EX VFD) increases to open the exhaust damper. If the building pressure is below the building pressure setpoint, the exhaust damper output (EX VFD) decreases to close exhaust damper.
The EX-FAN output energizes when the exhaust damper output is greater than the exhaust damper position fan on.
The EX-FAN output de-energizes when the exhaust damper output is less than the exhaust damper position fan off.