Smaller, lighter and with a higher output power than any other comparable single-phase protective relay test instrument, Megger’s new SMRT1 smart protective relay test set is ideally suited not only for testing older installations and legacy power plants, but also for meeting the future challenges associated with testing the smart grid and installations that use the IEC 61850 substation bus.
One of Megger’s fourth generation of automated relay test sets, the SMRT1 leverages the company’s patented developments to produce an instrument that offers higher output current, higher output power for both voltage and current outputs and greater precision than its predecessors, while addressing user demands for reduced size and weight — it weighs in at just 4 kg.
The SMRT Power Box is specifically designed to test protective relays that are used in conjunction with CTs having 1 A and 5 A secondaries. It combines the capacity to simulate high current faults with the amplifier precision needed to satisfy even the most demanding requirements.
The instrument has one current output channel, plus one convertible channel that can be configured as either a voltage or current output. This makes it possible, for example, to test single-phase current differential relays. With 2nd, 3rd, and 5th harmonic output capability the unit can also test harmonic restraint feature of differential relays.
Its patented design allows the SMRT1 to deliver the high power in both the voltage and current channels needed for high-burden applications, such as testing electromechanical relays. The unique Constant Power Output of the current amplifier produces a compliance voltage of 50 Vrms at 4 A (200 VArms), and maintains 200 VA output power up to 30 A. Of equal benefit is high current output capability; the SMRT1 current amplifier can deliver 30 A continuous, and up to 60 A for short durations for instantaneous overcurrent test applications.
To facilitate panel testing and the testing of electromechanical protection relays that demand a higher current voltage source, the high constant power output is also available from the new PowerV voltage amplifier. From 30 V to 150 V, the amplifier delivers a constant 150 VA, providing high current output at “difficult” low-test voltages.
As standard, the instrument incorporates an Ethernet port that can be used to interconnect multiple SMRT units creating a three-phase test set, or for connecting to IEC 61850 substation bus systems.
Megger’s new SMRT1 protection relay test set can be controlled using a laptop or manually with the optional Smart Touch View Interface (STVI), which provides a simple way of testing even the most complex relays. The STVI, with its large full-colour high-resolution touch screen, allows users to perform manual, steady state and dynamic tests quickly and easily, and has built-in preset test routines for most popular relays. For fully automated testing, the SMRT is supplied as standard with AVTS, Megger’s advanced visual test software package.