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G59/G99 Connection procedure

Does my installation apply?

This connection procedure applies to generation installations that are either rated above 16A (3.68kW) per phase or that do not meet the requirements of the current version of an Energy Networks Association (ENA) document called Engineering Recommendation G83.

Where this connection procedure applies, the generation and the installation must comply with the current version of ENA Engineering Recommendation G59. At this time there are two different versions of this document, G59/2-1 and also G59/3 and the requirements of either document may be followed. From 1st December 2014, only G59/3 is applicable. Copies of these documents can be obtained from the Energy Networks Association

What should I do?

You should apply using the appropriate G59  application form. Three different application forms are provided below.

The first application is applicable where the aggregate capacity of the generation is no greater than 75A per phase and the generators have been type tested to G59/2-1.

The second form is applicable where the aggregate capacity of the generation is no greater than 75A per phase and the generators have been type tested to G59/3 or to G83/2.

The third form is applicable where the aggregated capacity of the generation is above 75A per phase or where one, or more, of the generators have not been type tested to G59/2-1, G59/3 or G83/2.

If you would like us to consider more than one option then please explain this in a covering letter.

Once we have received your application we will check to see if your proposed generation can be connected to our existing network without additional work. If we do need to strengthen our network or if you need a new electricity connection we will give you an estimate for carrying this out. If you would like information on our connection charges please click here.

Once we have agreed all the details with you and we have carried out any necessary work on our network, you may go ahead and commission your generation.

Commissioning Requirements

If the aggregate rating of the generation at the premises is no higher than 75A per phase and all the generators have been type tested to G59/2-1 or G59/3 we do not normally need to witness generator commissioning tests. In such cases the installer shall complete the appropriate G59 Commissioning Confirmation Form and return it to us within 28 days.

If the aggregate capacity of the generation is above 75A per phase or if one or more of the generators has not been type tested to G59/2-1, G59/3 OR G83/2 then additional protection tests shall be carried out on site. The results of these additional test shall be recorded on the following form:

Furthermore, where the aggregate capacity of the generation is above 75A per phase or where one of more of the generators has not been type tested to G59/2-1, G59/3 or G83/2, we will need to witness some of the generator commissioning test. We make a charge for witnessing these tests. This charge is not included in any Offer made for providing a new or augmented electricity connection but will be charged and invoiced separately.  Where we have to make several visits to witness the commissioning tests, additional charges will apply. For further information please click here.”

For a copy of the ENA guide on connecting generation under the G59 Connection procedure click here.

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