Voltage Control Relays

Sometimes referred to as tap changer control relays, these products are used to control the on load tap changer (OLTC) connected to power transformers. We are able to offer different types of relay and accessory products.

Our Legacy Products have been in existence for over 25 years, many of which are still in service. With the rigorous standards we set ourselves, we can confidently say we see this continuing into the future.With demand for our market leading SuperTAPP SG Relay, we have withdrawn these products but will support the product hardware for a further 10 years.

Follow the links to find out more about our legacy products:

SuperTAPP SG is the latest realisation of the market-leading SuperTAPP range of AVC relays for transformer and tapchanger management.  SuperTAPP SG provides practical options to deliver a Smart Grid approach for distributed generation, network interconnection and reconfiguration, flexible and highly variable loads, and many other scenarios which cause challenges for voltage control.


Key Features:



The SuperTAPP n+ is owned and manufactured by Fundamentals. It was designed to solve problems associated with modern network issues such as embedded generation and power factor variations (reverse power etc). The relay offers patented functions which provide ultimate flexibility and future-proofing for the increasingly complex electricity network. The relay is compatible with the RTMU relay (monitor).

The SuperTAPP system comprises a voltage control relay type RVM and a tap changer monitor relay type RTMU.

The MicroTAPP voltage control relay was developed jointly with Reyrolle in year 2000. MicroTAPP is a numerical relay with built-in monitor functionality. It is manufactured by Siemens Reyrolle.