What Are Relay Testers?

The purpose of protective relay equipment is to sense fault states and trip circuit breakers. If a fault is not corrected early, personal injuries and serious damage can occur.

Are They Important?

Electric power grid protection systems guard extremely valuable equipment, and protective relay equipment plays a vital role in this protection chain. To ensure consistent reliability, protective relay equipment must be checked by testing at regular intervals.

Primary Injection Testing.

There are two main principles for testing protective relay equipment. For primary injection testing, high current is injected on the primary side of the current transformer. The entire chain - current transformers, conductors, connection points, relay protection and sometimes circuit breakers as well - is covered by the test. The system being tested must be taken out of operation during primary injection testing.

Secondary Injection Testing.

For secondary injection testing, the protective relay equipment is disconnected from the measuring transformers and the circuit breaker. The system being tested does not have to be taken out of operation.

Calibration of Relay Test Sets

Cuthbertson Laird Group have a long tradition of calibrating relay test equipment. For many years (prior to Meggers acquisition), we were the sole distributor of Programma test equipment in the UK. Our calibration labs were officially authorised to calibrate and repair their products. Today, as a Megger authorised service centre, we continue to calibrate and repair the Sverker range of relay test equipment.

Our Relay tester needs repairing - can you fix it?

Our manufacturer trained technicians can repair many faults in-house. We provide a free quotation before any work is undertaken, and will only proceed with a repair once we have your approval. If the tester needs to go back to the manufacturer we can usually provide you with a fixed price repair quote. We will arrange for the tester to be sent and returned to us after the repair.

Certain models of OMICRON protective relay equipment may have to be returned to the manufacturer for repair/calibration in Austria.

What is the turnaround time?

This depends on the workload in our labs and whether the instrument requires any repairs. For calibrations only our standard lead time is 3 to 5 working days. If the instrument has to be sent to a third party for calibration it will be longer. Your local office will advise you of the anticipated turnaround time. Please see above in regards to Omicron equipment.

Can You Supply Spare Parts?

In many cases we can. As a manufacturer authorised service centre we have access to their spares list. Please ring for details.