VSD talks to building controls

Building controls specialist Trend says it is offering the first variable speed drives that can connect directly to a building management system (BMS). It has developed a low-cost interface that allows any number of drives to be monitored and managed from any location, via a BMS.

The interface, called NXNI, is designed to link Trend`s Vacon-built NX drives to its own BMS. It can monitor up to 30 variables, such as speed, power, current, and torque, from pump and fan motors. It can also identify fault conditions and, where appropriate, allows a drive to be reset from, for example, a BMS supervisor in a maintenance department, or the offices of a contractor. Previously, this could only be done locally, at the drive.

The drives can be started or stopped, and their speed can be varied to meet demand, via a network. Drives can also communicate with each other so, for example, if one pump in a parallel pair fails, the other one will increase its speed automatically to compensate.

Using the new system, a single operator can monitor and adjust tens or hundreds of VSDs, even is they are spread across several scattered buildings.