The latest DIN-rail mounted KD relay from NewElec boasts a small footprint (L 80 x W 55 X H 136 mm) and measures motor load currents of up to 50 A without the introduction of additional current transformers. The current range may be extended for any current range using interposing CTs.

The KD relay offers two paramatization platforms, one for the electrician and another for the engineer. A patented start stall protection feature is available involving power factor measurements during acceleration. The user has a choice of load current or power factor measurement for minimum load detection.

Additional features include user-selectable priming time for pumps, defined permissible starts per hour, as well as consecutive start attempts. The KD relay provides voltage frequency monitoring, user-selectable upper and lower defined limits for over and under voltage measurements and phase reversal protection with user-selectable RWB or BWR phase sequencing.

A dynamic thermal reset facility optimises the reset time after an overload trip, and 2 000 events can be stored with time and date stamping. In addition, the last 60 faults may be stored with time and date stamping including value of interrupted current, mains voltage and power factor.

The KD relay has an earth insulation lock out as well as earth leakage protection with user-selectable sensitivities of 30 to 1 000 mA for instantaneous or IDMT tripping curves. Harmonic filtering is a standard feature.

The free front-end software issued with the product incorporates exceptional customer benefits. These include a recording utility that will record the RMS loads, mains voltages, power factor, as well as the thermal capacity for further processing in Excel. 
The software also allows access to the relay’s statistical data, access to a calculator for working out thermal trip times, cooling times, motor load currents, as well as earth leakage trip time delays for IDMT selected tripping curves. It is a very useful simulator that could be used for training or to obtain answers to ‘what if’ scenarios. The software also allows access to the 2 000 events and 60 last faults stored in the relay.

Accessories are available for a door-mounted remote display unit that includes an infrared data acquisition port for ease of relay access and setting up. A carry-case is available that includes a KD RDU programming unit, dispensing with a laptop, used for downloading / uploading of data using a USB memory stick for optimum versatility.