How to unleash your variable speed drive's true potential

摘要

The variable speed drive (VSD) has been in commercial usage for some 50 years, and has been a mainstay of HVAC systems for several decades. There's simply no other technology on the market that matches a VSD in its core competency of providing precise and energy efficient control of motor speed. However, to view a drive merely for starting and stopping motors is to miss the huge cost saving potential hidden under a modern VSD's bonnet. By utilising the advanced functions within the drive, consultants, OEMs and panel builders can eliminate potential redundant components and save space, as well as reducing panel component and installation costs by as much as 50 percent. Typically, a cabinet in a HVAC system will include thermostats used for controlling cabinet fans to save standby losses, timer relays, contactors and door-mounted HMIs. It may have an ammeter indicating amps or volts or true process values such as ambient temperature. And it might include a mini PLC for decision-making or for controlling the system to behave differently depending on the time of day, or to monitor variables in the field to inform how the equipment operates.