What size cable

rampantbunny

I'm building a house (self-build) and haven't gotten around to appointing an electrician yet.
Electric meter box installed and it will soon be plastered in. I've no ducting/cable run from bottom of box to house yet so want to do that this weekend.
Am installing a geothermal Heat Pump which I believe affects the electric supply I need (3 phase I think). What cable is run from the meter box to the house fuse board? 16 gauge?

2011

rampantbunny wrote: »

I'm building a house (self-build) and haven't gotten around to appointing an electrician yet.

You should get a Registered Electrical Contractor (REC) on board ASAP. Mistakes can be very costly. There is no point in being "penny wise and pound stupid".

Electric meter box installed and it will soon be plastered in. I've no ducting/cable run from bottom of box to house yet so want to do that this weekend.

There are specific requirements for this. It would not be advisable to proceed without the guidance of a REC.

Am installing a geothermal Heat Pump which I believe affects the electric supply I need (3 phase I think). What cable is run from the meter box to the house fuse board? 16 gauge?

How long is a piece of string?
At a minimum you will require 16sq. x 4 for L1, L2, L3 + N and a 10sq. CPC.
But depending mainly on the size of the load and length of run a larger cable may be required. You are likley to require a brown/brown 1.5 T+E for the dry contact in the ESB time clock if it is a dual tarriff meter (normal for heat pumps). It is unusual to require a 3 phase supply for a domestic installation even when it has a heat pump. The standing charge will be higher for this as will the connection fee. What calculation was carried out to determine that a 3 phase supply would be required? Was the option of an enhanced single phase supply considered?

If you run in the tails you are committing an offence. Since the 1st of October 2013 it has been illegal for a non-Registered Electrical Contractor to carry out most electrical work in domestic premises. Refer to the Restricted Works Decision Paper published by the Commission of Energy Regulation (CER). As detailed in the above document “Minor electrical works” are exempt from this legislation. However this work is not "minor works".

It is also likley that RECs will be reluctant to get involved with electrical work that has been started by an unqualified person. This type of work should only be carried out by or under the supervision of a suitabley qualified person.

Calahonda52

2011, thanks for the link to the document.
Have the fines and jail sentences portion been enacted yet?

Bruthal

I'd be surprised if anyone is ever charged with pulling a cable through a pipe.

Calahonda52

Bruthal wrote: »

I'd be surprised if anyone is ever charged with pulling a cable through a pipe.

I agree but if the RECI and RGII guys want to get real about this stuff then it needs to be reported, if they want anyone to take them even half seriously in their drive to cut out uncertified work.
In addition, the random supervisor checks need to be just that: random, and not phoning the guy the day before, asking where will he be.

2011

Calahonda52 wrote: »

2011, thanks for the link to the document.

No bother, although it is old news now.

Have the fines and jail sentences portion been enacted yet?

Yes.
The first prosecution resulted in a €3,000 fine.
See link.

I would imagine that the chances of being prosecuted are extremely low unless something goes wrong. Unfortunately a little knowledge can be a dangerous thing and many people that do not have the required training or experience attempt electrical work that is way beyond their ability. If this results in a fatality, serious injury, or a large insurance claim then their chances of being prosecuted under this legislation increase dramatically. I think that many DIYers forget that mains voltage is potentially lethal.

People forget that getting something electrical to "work" is generally quite simple. It is often far more difficult to get it working safely and complying with the regulations within a budget.

Bruthal

Calahonda52 wrote: »

I agree but if the RECI and RGII guys want to get real about this stuff then it needs to be reported, if they want anyone to take them even half seriously in their drive to cut out uncertified work.
In addition, the random supervisor checks need to be just that: random, and not phoning the guy the day before, asking where will he be.

Well my point is, is it actually against their endless rules to pull a cable through a pipe and nothing more.

Of course, the first year apprentice, or the contractors son in laws mate can safely pull it in, should there be any problems.

rampantbunny

2011 wrote: »

You should get a Registered Electrical Contractor (REC) on board ASAP. Mistakes can be very costly. There is no point in being "penny wise and pound stupid".



There are specific requirements for this. It would not be advisable to proceed without the guidance of a REC.



How long is a piece of string?
At a minimum you will require 16sq. x 4 for L1, L2, L3 + N and a 10sq. CPC.
But depending mainly on the size of the load and length of run a larger cable may be required. You are likley to require a brown/brown 1.5 T+E for the dry contact in the ESB time clock if it is a dual tarriff meter (normal for heat pumps). It is unusual to require a 3 phase supply for a domestic installation even when it has a heat pump. The standing charge will be higher for this as will the connection fee. What calculation was carried out to determine that a 3 phase supply would be required? Was the option of an enhanced single phase supply considered?

If you run in the tails you are committing an offence. Since the 1st of October 2013 it has been illegal for a non-Registered Electrical Contractor to carry out most electrical work in domestic premises. Refer to the Restricted Works Decision Paper published by the Commission of Energy Regulation (CER). As detailed in the above document “Minor electrical works” are exempt from this legislation. However this work is not "minor works".

It is also likley that RECs will be reluctant to get involved with electrical work that has been started by an unqualified person. This type of work should only be carried out by or under the supervision of a suitabley qualified person.

That's me told

Don't want anyone getting the wrong idea here before this gets legs and it appears I'm attempting to wire my house. It's not 100% self-build..professionals will be engaged to complete the works.

Electricity is a dangerous thing in the hands of most (and maybe I'm in that category) but it doesn't get much simpler than running a 3m length of cable from a to b in suitable ducting...no connection to anything.
As an aside, is 'running in the tails' the official term for describing what I'd planned to do?

Incidentally, I spoke with two reci members in the past few weeks, both too busy to take on the job at the moment. When asked if they'd manage running the cable with the cavities pumped (bead) they said (both) that I could pick up some cable and sleeving in such and such a place and run it myself. I didn't think to ask them what gauge at the time.

From ESB application form:
Note also that a 16kVA connection is usually required for a house with a standard single phase heat pump
Sorry, thought I'd read that 3 phase was necessary. Some Heat Pumps are 3 phase but majority are single (info from heating installer). Will confirm, but on the face of it an enhanced supply 'should' be sufficient.
I admit with questions like I've asked there is always the unquantifiable piece of string. But at a very basic level, I'd have thought there'd be a certain size cable heavy enough to cater for supply to most typical houses...I'd actually be surprised if there were too many variations tbh.

Not calling you out or anything 2011, (you are the modfather after all) but why the 'penny wise pound stupid comment'?
No sparks appointed yet because candidates are busy, and I'm time poor (not cash poor fortunately) and its a self build because I can control quality.

Bruthal

rampantbunny wrote: »

That's me told .

From ESB application form:
Note also that a 16kVA connection is usually required for a house with a standard single phase heat pump
Sorry, thought I'd read that 3 phase was necessary. Some Heat Pumps are 3 phase but majority are single (info from heating installer). Will confirm, but on the face of it an enhanced supply 'should' be sufficient.
I admit with questions like I've asked there is always the unquantifiable piece of string. But at a very basic level, I'd have thought there'd be a certain size cable heavy enough to cater for supply to most typical houses...I'd actually be surprised if there were too many variations tbh.

Length of run, and size of load are 2 variations which can be very wide ranging.

Not calling you out or anything 2011, (you are the modfather after all) but why the 'penny wise pound stupid comment'?

Because most try to keep costs to a minimum. Often saving a couple of euro early on, ends up costing a large amount later on. So it's not a stupid comment really.

rampantbunny

Bruthal wrote: »

Length of run, and size of load are 2 variations which can be very wide ranging.

I'm satisfied that it's not possible to 'guess' what size cable is appropriate so fine on that front. Still, even with the variations in load, does it not come down to a few choices of cable as opposed to a large selection?

Bruthal wrote: »

Because most try to keep costs to a minimum. Often saving a couple of euro early on, ends up costing a large amount later on. So it's not a stupid comment really.

Think you've misunderstood me Bruthal...I've not called it a stupid comment. That text is part of the original text I was referring to.

Understand what you are saying re. most trying to keep costs down (isn't everyone), but a large part of the reason mine is a self-build is as I said I've more control over quality i.e. getting the best tradesmen I can find. Cost does come into it, but not at the sacrifice of good work and finish. TBH it rankles when the term self-build gets translated into something resembling can-do-it-all-himself or miser etc. but maybe I'm overly defensive on that front.

2011

rampantbunny wrote: »

Don't want anyone getting the wrong idea here before this gets legs and it appears I'm attempting to wire my house. It's not 100% self-build..professionals will be engaged to complete the works.

Fair enough.

Electricity is a dangerous thing in the hands of most (and maybe I'm in that category) but it doesn't get much simpler than running a 3m length of cable from a to b in suitable ducting...no connection to anything.

To be fair your question in your first post was about sizing a cable for a 3 phase load. You did not ask how to pull a cable though a duct.

Incidentally, I spoke with two reci members in the past few weeks, both too busy to take on the job at the moment. When asked if they'd manage running the cable with the cavities pumped (bead) they said (both) that I could pick up some cable and sleeving in such and such a place and run it myself. I didn't think to ask them what gauge at the time.

Have a look at this. It is important altho this cable is installed in a particular way or the ESB may refuse to connect you. For a 16kVA supply the minimum size that I would install is a 25sq. mm T + E. That is to to say that larger will not be required.

Sorry, thought I'd read that 3 phase was necessary. Some Heat Pumps are 3 phase but majority are single (info from heating installer). Will confirm, but on the face of it an enhanced supply 'should' be sufficient.

Generally it is sufficient. There are lots of advantages to having a 3 phase supply, but generally these advantages are not worth the extra cost for a domestic customer.

I admit with questions like I've asked there is always the unquantifiable piece of string. But at a very basic level, I'd have thought there'd be a certain size cable heavy enough to cater for supply to most typical houses...I'd actually be surprised if there were too many variations tbh.

Generally a 16 sq. T + E is sufficient, but when someone intends to install a heat and they say that they think they need 3 phase supply that could mean anything.

Not calling you out or anything 2011, (you are the modfather after all) but why the 'penny wise pound stupid comment'?

Sorry if I offended you.
But.....you would be amazed how many people decide that they will save money by designing a the wiring in their home and connecting up all sorts lethal wiring. Then they expect an electrician to take ownership of their mess, certify it and give them a discount.

I remember one individual that wired his lights in alarm cable. The insulation was dripping off it like melting wax. He refused to accept that there was anything wrong with what he had done and wanted me to connect more of his handiwork to the distribution board.

No sparks appointed yet because candidates are busy, and I'm time poor (not cash poor fortunately) and its a self build because I can control quality.

If you want quality and to do the work once it would be better to hold off until the electrical design is completed.

Bruthal

rampantbunny wrote: »

I'm satisfied that it's not possible to 'guess' what size cable is appropriate so fine on that front. Still, even with the variations in load, does it not come down to a few choices of cable as opposed to a large selection?

It does, but once it's more than 1 choice, it can't be answered when asked what size cable do I need from meter to board, without the all important length and load info. We could say it will likely be 16 or 25 square, or even 35 square, but then the question asked still remains unanswered.

I think the original question mentioned 3 phase too.

rampantbunny

Thanks all.

I ran a 16 square (it is what I had leftover from other job) cable through sleeving at the weekend. The important part of the exercise is that the sleeving is now in place and depending on final electrical spec. the cable itself can be removed and a heavier one installed or left as is if deemed suitable.

Surprised at how easily the 16 square ran through...no doubt will be more difficult with heavier cable, but I ran a length of strong cord in the sleeving also so that will help on that end (or removal of the 16 can be used to pull the other).

rampantbunny

2011 wrote: »

I remember one individual that wired his lights in alarm cable. The insulation was dripping off it like melting wax. He refused to accept that there was anything wrong with what he had done and wanted me to connect more of his handiwork to the distribution board.

Think you have to be dead to qualify for a Darwin Award but that fella should at least book a spot.

Bruthal

rampantbunny wrote: »

Think you have to be dead to qualify for a Darwin Award but that fella should at least book a spot.

Then we should all book spots.

rampantbunny

Bruthal wrote: »

Then we should all book spots.

Not sure I'm understanding if you are understanding, but I'll say it anyway..
Being dead isn't the only qualifying factor. You have to get there with a certain style, usually a blatant disregard for your survival.

Bruthal

rampantbunny wrote: »

Not sure I'm understanding if you are understanding, but I'll say it anyway..
Being dead isn't the only qualifying factor. You have to get there with a certain style, usually a blatant disregard for your survival.

Most of us have probably done something sometime, which was close to assisting our demise. I see it every day on the roads as one single example.

egizz983

https://www.boards.ie/discussion/comment/94373762#Comment_94373762

Would installing spotlights( drilling holes and pulling up new cables ) would classify as major work or minor ? also disconnecting unused circuits from fuse board ?

meercat

https://www.boards.ie/discussion/comment/121455234#Comment_121455234

this would definitely be restricted work and should only be carried out by a registered electrical contractor who should provide a certificate 3 on completion

egizz983

https://www.boards.ie/discussion/comment/121456030#Comment_121456030

i have heard stories that sometimes people do them self and then call certified electrician to check everything and provide certificate is that legit ?

smuggler.ie

me to..., heard STORIES...

meercat

https://www.boards.ie/discussion/comment/121554047#Comment_121554047

It’s absolutely against regulations

2011

I think this has been done to death. The answers to all questions raised in this thread were answered in the first few posts.

Thread closed.