Modulating power exhaust with VFD - Johnson Controls - LIT-12011950 - Building automation software - Smart Equipment Controller - 5.0

Smart Equipment Controls Sequence of Operation Technical Bulletin

Brand
Johnson Controls
Product name
Smart Equipment Controller
Document type
Technical Bulletin
Document number
LIT-12011950
Version
5.0
Revision date
2024-06-06
Product status
Active
Language
English

Setpoints and related data

The setpoints and related data include the following items:

  • Power exhaust fan type (ExFType) variable frequency fan
  • Building pressure setpoint (Bldg-Sp)
  • Building pressure reading (Bldg-Pres)

Inputs

The input for modulating power exhaust with VFD is 0 to 5 VDC from building pressure sensor to terminal BLDG PRES.

Outputs

The outputs include the following items:

  • 2 to 10 VDC from EX VFD
  • 24 VAC from EX-FAN

Operation

If the building pressure is above the building pressure setpoint, the exhaust output (EX VFD) increases. If the building pressure is below the building pressure setpoint, the exhaust output (EX VFD) decreases.

The EX-FAN binary output is energized any time the EX VFD analog output is greater than 2.16 VDC.

The EX-FAN binary output is de-energized any time the EX VFD analog output is less than or equal to 2.16 VDC.

The rate of change of the analog output is determined by the deviation form setpoint and length of time away from setpoint.