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When is a PEI not a PEI?

"Prosumer" Electrical Installation that is - i.e. an installation that can both produce and consume electricity.

I've been looking over the new Part 8.

It seems to describe quite a sophisticated setup - a "smart" system if you like - dynamically changing things according to some pre-programmed algorithms - maybe to minimise imports, perhaps to export 'when the price is right', deciding whether storage (if present) should accumulate or release, or something else. There even seems to be a specific requirement that a PEI incorporate an 'Electrical Energy Management System' (EEMS) (822.4).

Which got me thinking - how does a conventional ("dumb") grid-tied PV system fit into this? - where the amount of power generated locally is uncontrolled (i.e. just depends on external variables such as sunlight) and the only "management" is what can be achieved using a length of copper and Ohm's Law (i.e. any surplus just gets exported).

Is the idea that such installations should be smarter in future, or is it just that the non-existent management system of a typical PV system can just scrape through as a 'minimal' EEMS?

    - Andy.

Parents
  • Are you sure? There are two lowercase Roman indents in 461.2, and the Neutral need not be isolated if either condition is met, not both.

    As i read it, the requirement that 'protective equipotential bonding is installed and ... ' is in the leading paragraph and so applies either way.

    (quite what "connected to Earth by a low resistance to meet the disconnection times..." is supposed to mean is a quite different point of contention)

      - Andy.

Reply
  • Are you sure? There are two lowercase Roman indents in 461.2, and the Neutral need not be isolated if either condition is met, not both.

    As i read it, the requirement that 'protective equipotential bonding is installed and ... ' is in the leading paragraph and so applies either way.

    (quite what "connected to Earth by a low resistance to meet the disconnection times..." is supposed to mean is a quite different point of contention)

      - Andy.

Children
  • I see what you're getting at now ... so there's potentially a debate around whether 'not installed' equates to 'not required' (it could be argued, converse to your assertion, that if I don't need protective bonding in a building, because there are no extraneous-conductive-parts then I have indeed installed protective earthing and bonding to meet the requirements of Regulation Group 411.3.1).

    Arguably, if none of the accessible metal parts are extraneous-conductive-parts, and all others that might be affected by potential are exposed-conductive-parts (or connected to exposed-conductive-parts) then it doesn't really matter.

    So I guess it just depends which perspective you take (or the guidance takes ... GN2 appears to err on the permissive side, for example ... para 2 page 47 of the 9th Ed 2022).

  • way.

    (quite what "connected to Earth by a low resistance to meet the disconnection times..." is supposed to mean is a quite different point of contention)

    Your not the only one, the NICEIC Technical Helpline admitted that they had no idea!