£90 module `smashes entry costs to smart motor control`

Rockwell has launched a £90 add-on DeviceNet communications module for its electronic overload relays, with the claim that it will make real-time monitoring and control of motors affordable in many applications where the costs were previously prohibitive. "It smashes the price entry point to intelligent motor starting and monitoring," declares Jeff Stewart, Rockwell`s components business manager.

The 18mm-wide DeviceNet module (above) mounts on the side of an Allen-Bradley E1 Plus overload relay, allowing motor parameters such as current, thermal capacity, status, warnings and trips to be monitored continuously over a network and displayed on a PC or HMI. It also gives access to E1 Plus functions such as jam protection, overload and underload warnings, and trip history.

The module has two inputs and a relay output, allowing it to provide remote motor management at a fraction of the price of conventional high-end systems, according to Rockwell.

The E1 Plus and the communications module are part of Rockwell`s MCS (Modular Control System) range. The electronic relays cover currents from 0.1-800A in five sizes, and incorporate phase detectors that react in less than 3s. They use sophisticated models of motor performance to monitor loading without needing heating elements, thus generating less than 2.5% of the heat of a traditional bimetallic thermal overload relay.