Accelerated Loss of Mains Change Programme

We upgrade your G59 relay, free of charge, to ensure you remain compliant with the Grid Code.

Apply for a free upgrade or Learn more below

Regulation changes

There have been significant changes in the requirements for the connection of relays with the roll out of G99, which replaced G59/3-4 from 27 April 2019.

Generators connected to the network after February 2018 that currently use G59/3-4 will need to upgrade to G99.

Generators connected to the network before February 2018 will not need to comply with G99, however they must be fully compliant with G59/3-4. This retrospective upgrade is being covered by the Accelerated Loss of Mains Change Programme.

Going forward, the only Loss of Mains (LoM) protection that is permitted is Rate of Change of Frequency (RoCoF) with a setting of 1Hz/s and a time delay of 500ms. Vector Shift (VS) and the old RoCoF setting of 0.125Hz/s are no longer permitted as a LoM protection.

What we do

We can replace or re-program your G59 relay for free to ensure you remain compliant with the latest Grid Code.

We have an excellent working knowledge of ABB, ComAp, Deepsea, DEIF, Megacon, Woodward, Schneider’s Sepam and MiCOM relays, controlling all types of generation: Solar PV, Battery Storage, CHP, Biomass, Gensets, Hydro, Wind Turbines etc.

We provide Senior Authorised Person (SAP) services.

Our engineers are ex-DNO employees and have been trained to operate a wide range of Oil, SF6 and Vacuum switchgear.

How it works

  1. Fill in the application form below

    We will let you know within 48 hours whether we are able to upgrade your relay or ask further questions to learn more.

  2. Sign a 'Letter of Authority' form

    If we are able to help, we will request for you to sign a 'Letter of Authority' form to enable us to act on your behalf and carry out the upgrade for you.

  3. Our engineers perform the upgrade

    We will arrange a time to perform the upgrade. An engineer will visit your site and perform the necessary changes.

  4. We collect payment from the programme

    We won’t charge you anything — the application, works and verification will be free of charge for you and we will be paid by the programme.

Apply for a free upgrade

Why choose us?

We have 7 years of experience in electrical installations up to 132kV and working closely with DNOs in the UK.

We will undertake all activities required to get your generator installation compliant – from application, through settings modification, relay replacement or testing, all performed with the highest standards for quality and safety.

Apply for a free upgrade

Contact information
Equipment information

Please provide the postcode or the county name.

For example, Solar PV or Battery Storage.

Write down any questions or additional information you want to share.

We won’t share any information provided with third parties.

Have questions?

Feel free to email us at contact@bumac.uk with any questions.