UK specs for Embedded generators 1

[ampy]

Hi all,
Can anyone tell me what the local supply authorities require in terms of protection / earthing for small (Sub 500KVA) gen sets.

 

[DanDel]

What is the output voltage, and what is your location?

 

[bigamp]

In the UK, the minimum protection requirements are specified in a document referred to as ER G59/1, "Recommendations for connection of embedded generating plant to the Regional Electricity Companies Distribution Systems, published by the Electricity Association" (last updated in 1995, cost about 55 quid).

Regional Electricity companies may have additional or further specific requirements. You would need to check with the one you are planning to connect to to see what their requirements are. I would expect that most will have a document of some sort on the subject they will be able to give you.

The end user may also have specific requirements for the operation of the embedded generator and the protection system will also need to satisfy these. Depending on what is required for the installation as a whole, the protection scheme may range from being a minimalistic G59/1 scheme through to something much more complex.

One thing that will be required if you are operating in parallel with the utility is a fast acting loss of grid detection system based either on rate of change of frequency or voltage vector shift.

Generator earthing is really going to depend on operating voltage (LV/MV) and what your requirements are. An LV generator would need to be directly earthed I expect.

Regards

 

[ampy]

The set will be 415V it was the sort of earthing I might need ie earthmats to get the figure below 1 Ohm.

 

[jbartos]

Suggestion: Check for NETA as mentioned in

http://www.gnn.gov.uk/gnn/national.nsf/TE/3B5ACEBFEA978B358025683500320CFA?opendocument

 

[tomatge]

Bigamp has given you the answer you need.

I'll also add there there is a suuplementary documnent to G59 which is called ETR113. This provides lots more useful information and some technical advice as to how G59 should be implemented. It is also an Electricity Association publication.