Advertorial - There’s more to a VSD than meets the eye

Engineering optimisation

ABB’s Chris Plumb explores some of the hidden functionality that can help users of variable speed drives (VSDs) to further optimise their HVAC processes, as well as save energy.

It’s a misconception that a variable speed drive (VSD) is solely for controlling a motor’s output. Through “Engineering Optimisation”, modern VSDs incorporate an increasing amount of advanced functionality that can help to prevent “doubling up” of cabinet components, achieving more by assessing installation requirements, reducing cabinet size to save space, utilising panels in other ways and ultimately lowering costs.

For instance, many cabinets will contain thermostats for controlling cabinet fans to save standby losses. A VSD has its own thermostat, which can be linked to cabinet cooling fans to turn them on automatically when the VSD’s fans are activated.

A real-time clock built into the drive allows timers to be set up to either start or stop an application from running, depending on operating conditions. This eliminates the need for timer relays while the drive’s unused I/O can be utilised to gather telemetry onto the fieldbus system. A VSD also incorporates a range of energy management and performance analysis tools, removing the need for external energy meters, while retaining full compatibility with BACnet and Modbus protocol. Indeed, a VSD can even carry out many PLC functions using its integrated PID loop controller to vary motor output based on set points relating to building occupancy, time of day, and other variables.

Modern drives are also packed with features for functional safety, performing roles that would normally be carried out by contactors. As well as saving space, this also means one less component to install, check and maintain.


If you have any questions about Engineering Optimisation, or about ABB variable speed drives for HVAC in general, contact Chris Plumb directly at, on 01925 741111, or find him on LinkedIn.

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