Connection of back-upgenerator to TN-C-S domestic installation

Kendo51 said:

2.Wired back to a 20amp double pole rcbo enclosure in distribution cupboard.

20A RCBO for a generator that can supply 7.5kVA.  Shouldn't that be 32A?

Dave Miller said:

"generators", they apply to "person[s]"

For the purposes of ESQCR, 'generators' are 'legal persons' not pieces of equipment.

Hi Dave, thankyou excellent point, I've read over them several times with the assumption in my head its generators. Great point , the more discussion the more clearer things become.

gkenyon said:

For the purposes of ESQCR, 'generators' are 'legal persons' not pieces of equipment.

Specifically:

“generator” means a person who generates electricity at high voltage for the purpose of supplying consumer’s installations via a network; 

(See Regulation 1 Citation, commencement and interpretation)

This is the nuance with discussion that helps us all understand better. Thankyou gkenyon  

Quite so, but is this topic not about low voltage (< 600 V phase to earth AC).

So the OP's generator isn't a generator.  And the OP isn't a generator either, because their generator (that isn't a generator) doesn't run at high voltage.

Simple!

Chris Pearson said:

Quite so, but is this topic not about low voltage (< 600 V phase to earth AC).

Indeed ... that means that if you provide generation at 'low voltage' (such as many solar farms on the AC side), you might not be covered by the term 'generator' as defined in ESQCR ... but more pertinent to this discussion, it also means that if you are a 'prosumer' you are also not a 'generator' as far as ESQCR is concerned.

Simon Barker said:

generator (that isn't a generator) doesn't run at high voltage.

I would perhaps say that the AC side of their generator doesn't run at high voltage, but that's perhaps another debate which is not, perhaps, completed.

the OP's generator isn't a generator.  And the OP isn't a generator either, because their generator (that isn't a generator),,,

And that, ladies and gentlemen, is the sort of thing that happens when you let the legal chaps draft anything technical, and then let politicians edit it. Too many holes.

What for example if I had an LV generator and stepped it up to HV to run the length of a large farm and then stepped it back down to LV before it was used to supply any loads ?  (I am aware of at least one of these in the UK )  

So it is far more important that this installation is safe for its users, and can not damage  the DNO network, or rely on it when it may not be there for earthing, than agonising over which bit of legislation is or is possibly not appropriate, though it is quite fun.

Unless the OP refers himself to the police, who probably won't be interested anyway, we'll never know.  The only time such laws are tested in earnest is after there has been a serious accident and then some sort of inquiry, and the trick is to avoid that under all circumstances.

Mike.

yes, there are some parts of the supply regs which apply to legal entities who are "generators" as defined in the regs. however, there are other requirements (including regs 21 & 22 of the supply regs and regs 22 & 23 of the statutory rules for Northern Ireland) which apply to any person:

• reg 21/22: Where a person operates a source of energy as a switched alternative to a distributor’s network, he shall ensure that that source of energy cannot operate in parallel with that network and where the source of energy is part of a low voltage consumer’s installation, that installation shall comply with British Standard Requirements.
• reg 22/23: (1) Without prejudice to regulation 21[/22], no person shall install or operate a source of energy which may be connected in parallel with a distributor’s network unless he—
  (a) has the necessary and appropriate equipment to prevent danger or interference with that network or with the supply to consumers so far as is reasonably practicable;
  (b) has the necessary and appropriate personnel and procedures to prevent danger so far as is reasonably practicable;
  (c) where the source of energy is part of a low voltage consumer’s installation, complies with British Standard Requirements; and
  (d) agrees specific requirements with the distributor who owns or operates the network.
  (2) Sub-paragraphs (b) and (d) of paragraph (1) shall not apply to a person who installs or operates a source of energy which may be connected in parallel with a distributor’s network provided that sub-paragraphs (a) and (c) of paragraph (1) are complied with; and
  (a) the source of energy does not produce an electrical output exceeding 16 amperes per phase at low voltage;
  (b) the source of energy is configured to disconnect itself electrically from the parallel connection when the distributor’s equipment disconnects the supply of electricity to the person’s installation; and
  (c) the person installing the source of energy ensures that the distributor is advised of the intention to use the source of energy in parallel with the network before, or at the time of, commissioning the source

you will observe that these key requirements (including preventing danger and complying with the wiring regs when in scope) apply to any person with a source of energy. reg 22/23 is so important that it applies retrospectively, which isn't generally the case when new rules are introduced

I agree that what matters most is that the installation is safe, but I think that understanding the legislation does matter too. I'm sure that there's something in UK-SPEC about understanding relevant legislative and regulatory frameworks, so you don't have to take my word for it.

There seems to me to have been some confusion in this discussion about which rules apply where, so I want to avoid people thinking that certain rules don't apply to their installations because they've seen what appears to be a loophole but the parliamentary draughtsman has been smarter than they may have been given credit for. the key rules apply to any person who operates a source of energy

yes, there are some parts of the supply regs which apply to legal entities who are "generators" as defined in the regs. however, there are other requirements (including regs 21 & 22 of the supply regs and regs 22 & 23 of the statutory rules for Northern Ireland) which apply to any person:

• reg 21/22: Where a person operates a source of energy as a switched alternative to a distributor’s network, he shall ensure that that source of energy cannot operate in parallel with that network and where the source of energy is part of a low voltage consumer’s installation, that installation shall comply with British Standard Requirements.
• reg 22/23: (1) Without prejudice to regulation 21[/22], no person shall install or operate a source of energy which may be connected in parallel with a distributor’s network unless he—
  (a) has the necessary and appropriate equipment to prevent danger or interference with that network or with the supply to consumers so far as is reasonably practicable;
  (b) has the necessary and appropriate personnel and procedures to prevent danger so far as is reasonably practicable;
  (c) where the source of energy is part of a low voltage consumer’s installation, complies with British Standard Requirements; and
  (d) agrees specific requirements with the distributor who owns or operates the network.
  (2) Sub-paragraphs (b) and (d) of paragraph (1) shall not apply to a person who installs or operates a source of energy which may be connected in parallel with a distributor’s network provided that sub-paragraphs (a) and (c) of paragraph (1) are complied with; and
  (a) the source of energy does not produce an electrical output exceeding 16 amperes per phase at low voltage;
  (b) the source of energy is configured to disconnect itself electrically from the parallel connection when the distributor’s equipment disconnects the supply of electricity to the person’s installation; and
  (c) the person installing the source of energy ensures that the distributor is advised of the intention to use the source of energy in parallel with the network before, or at the time of, commissioning the source

you will observe that these key requirements (including preventing danger and complying with the wiring regs when in scope) apply to any person with a source of energy. reg 22/23 is so important that it applies retrospectively, which isn't generally the case when new rules are introduced

I agree that what matters most is that the installation is safe, but I think that understanding the legislation does matter too. I'm sure that there's something in UK-SPEC about understanding relevant legislative and regulatory frameworks, so you don't have to take my word for it.

There seems to me to have been some confusion in this discussion about which rules apply where, so I want to avoid people thinking that certain rules don't apply to their installations because they've seen what appears to be a loophole but the parliamentary draughtsman has been smarter than they may have been given credit for. the key rules apply to any person who operates a source of energy

Dave Miller said:

you will observe that these key requirements (including preventing danger and complying with the wiring regs when in scope) apply to any person with a source of energy. reg 22/23 is so important that it applies retrospectively, which isn't generally the case when new rules are introduced

and similarly Regulation 21 (22 in NI) if the generator operates as a switched alternative, this needs to provide safety for those working on the distribution network, and BS 7671 is to be used.

Interesting with these two Regulations in ESQCR, it is the 'person' who 'operates' the generator (that could be, again, a 'legal person' as an entity), not the installer, who has the duty under the Regulations, and might be proceeded against under the Regulations (unlimited fine I believe).

However, that would not stop the 'person who operates' being able to take action against an installer if the installer were the designer recommending the change to the electrical installation.

I imagine that there's a CDM angle to this, where ultimately the client is responsible for appointing the right people to do the right things

I'm not for one moment suggesting we should not consider the intention of the legislation, but the presence of the Double Pole change over switch means this example is NOT source of energy (what we call a 'generator' ;-) ) which may be connected in parallel with a distributor’s network (what we call 'the mains' ).

Unless you think 'connected in parallel' does not mean electrically in parallel.

However, failing that first test does not mean that it should not be wired up without due diligence.

Things that can be configured to synchronise and export power back out and onto the grid are quite a different matter, as in fault states, they have potential to damage both the network and other users equipment, and quite rightly are treated with more rigour.

Mike.

agreed: it's then caught by reg 21/22, which requires a robust change-over and also compliance with the wiring regs

Dave Miller said:

I imagine that there's a CDM angle to this, where ultimately the client is responsible for appointing the right people to do the right things

Agreed, although worth noting further that, where there is a 'domestic Client' (work done for a private homeowner) the Contractor takes on the Client's duties under CDM ...

mapj1 said:

I'm not for one moment suggesting we should not consider the intention of the legislation, but the presence of the Double Pole change over switch means this example is NOT source of energy (what we call a 'generator' ;-) ) which may be connected in parallel with a distributor’s network (what we call 'the mains' ).

I never suggested it was ... it remains true, however, that the arrangement is covered by Regulation 21 of ESQCR (Regulation 22 of ESQCR NI) and I agree in this case Regulation 22 of ESQCR (Regulation 23 of ESQCRNI) would not apply.

Hi Dave , valuable contribution, i appreciate your taking the time. I agree interpretation when reading and understanding regs/legislation  can lean/interpreted to making it work for individuals requirements. My intention in raising the questions was to remove my individual bias if you like, have good open discussion with better minds than my own frankly and reach overall consensus. Grateful to all contributions. 

Hi Mike, what you refer was my initial train of thought.

Which id replied to gkenyou broadly saying i believe regs in G99/NI and ESQCR didn't apply/out of scope to my installation (back up emergency supply only designed for owners property/ Island mode only as it referred) this was because for the most part they reference "export" ,"paralleling" and syncing and such like onto DNO/grid/network..

gkenyou, rightly pointed out that they do apply and kindly reference me back on some of them, my intent dismissing them originally wasn't to say i hadn't taken them into consideration before posing the question, more that in the small area i had to consider within them, that my proposed install would be meeting requirements. That said was glad gkenyon did so helped in retracing areas i may have failed to consider. 

Your train of thought seems was similar to my own that once "double pole" "break before make" bypass/change-over was in place conditions has been met and that my generator was no longer a "source or Energy" which had the ability to connect in parallel to dist network

From that thinking and as below from ESQCR.

Kendo51 said:

Regulations 26(1) and 26(2) of the ESQCR require the consumer’s installation to be:"...so constructed, installed, protected and used or arranged for use so as to prevent, so far as is reasonably practicable, danger or interference with the distributor’s network or with supplies to  others." 

"Danger and interference", to my thought process , if my generator is operating during a power failure (which majority is due to a line fault) and im connected still to the DNO earth, and potentially my generator/installation could develop a fault and i introduce fault current .......so thoughts then went on to eliminate this why not just switch the earth in the same "break before make" bypass switch.

Prosumer Electrical Installation 4.1 Earthing

"An electricity supply company may provide an earth at the point of connection but its primary function is protection of the network upstream from the installation. Under the requirements of the Electricity Supply Quality and Continuity Regulations (ESQCR), the consumer is responsible for ensuring that the installation is satisfactorily earthed"

Kendo51 said:

My thoughts here when operating in PEI and in grid terms "island mode" ,"consumer to responsible own earthing" , "earthing arrangement using a transfer switching device to facilitate the connection to the earthing arrangement of the local star/mid-point or the local exposed conductive parts" and by using a switched earth to customers own earthing system (in emergency use /island mode) whilst isolated from DNO. regulation is fulfilled "reasonably practicable, danger or interference with the distributor’s network or with supplies to  others." as i am only generating during mains failure tbh 99% time is this is due to a network fault, earth switching would prevent fault current back feed from DNO and indeed if i have a fault when in "grid terms" "island mode" no chance of me introducing earth fault onto DNO grid

Hopefully a consensus from and by others on what id originally proposed and the correctness of such can either be agreed or indeed rebutted..

To further muddy the water in this case when the "domestic client" is also the contractor....

Kendo51 said:

To further muddy the water in this case when the "domestic client" is also the contractor....

Yes, I had that in mind too ... nowhere to run and hide?