6.6202.7 Installation and Control of Variable Frequency Drives on Fans

Topic: 
Whole Building Ventilation
Subtopic: 
Components
Desired Outcome: 
Improved fan efficiency and control
TitleSpecification(s)Objective(s)
6.6202.7a
Evaluate existing fans, motors, and ventilation system

Motors will be evaluated to determine compatibility with variable frequency drive (VFD)

Load profile and source equipment will be analyzed for use of VFD to provide variable ventilation rates

Control strategy will be determined (e.g., manually adjusted speed or remote sensor control)

Ensure existing motors and ventilation system are compatible with VFD operation

6.6202.7b
Remove and replace motor, if required

Power supply will be disconnected; existing motor will be removed and replaced with motor suitable for VFD operation

Provide motor suitable for VFD operation

6.6202.7c
Remove motor starter and replace with VFD

Power supply will be disconnected; existing starter will be replaced with VFD in accordance with manufacturer specifications

Install and connect VFD

6.6202.7d
Install required sensors to implement VFD control strategy (for sensor controlled strategies)

Feedback sensors will be installed in accordance with manufacturer specifications at locations that will optimize chosen control strategy

Feedback sensors will be wired to VFD in accordance with manufacturer specifications

Ensure sensors are installed to optimize VFD operation

6.6202.7e
Install required manual controls to implement VFD control strategy (for sensor and/or manual controlled strategies)

Speed controls will be installed in accordance with manufacturer specifications at a location for ease of continued operation

Ensure manual controls are installed to optimize VFD operation, and for ease of installer and continuous operation

6.6102.7f
Restore power supply to VFD, and verify operation of VFD and fan

Power supply will be restored

VFD will be shown to be capable of operating fan

VFD will be shown to be capable of receiving sensor signals

Ensure that VFD is ready for setup

6.6101.7g
Initial setup of VFD

VFD parameters will be set up to accept feedback from sensors dependent upon chosen control strategy

System will be optimized to ensure targeted design ventilation rates at the lowest possible speed setting

Achieve targeted design ventilation requirements with reduced electrical energy use