Branch circuits to buildings

[pauljpickering8]

Hopefully a quick and easy one...

Ive had a look through the regs but the only version this company give us is a .PDF format and its really annoying trying to look through it on the computer so hoping one of you Reg masters can help me out.

Right...For example lets says we have four buildings...A,B,C & D.

On building A there is a panel (4 way 3 phase) are you allowed to run 3 seperate circuits to each building and not have a panel inside the building itself. So Building A will have a panel mounted outside with 3 circuits running inside, then 3 to building B etc etc.


I think I have seen it somewhere that your not allowed, but I have been skimming over the American regulations


I'm not the one doing this work it is a repair team and they are going to explain this to me tomorrow and I dont want to agree if it is wrong because I know they'll try to bring it back to me when it all goes wrong.

Hope it makes sense what I'm asking and thanks in advance.

 

[telectrix]

how are they proposing isolation for each building. ?

 

[pauljpickering8]

From the panel on Building A, none of the buildings are attached by the way, all seperate. I thought I had read somewhere that each seperate building must have its own panel but could remember if that was in American Regs...

 

[Des 56]

What earthing system is present and do these seperated buildings have metalic services or structure

Also where the means of isolation is remote,there needs to be a non interchangeable lock off handle or such to secure that means of isolation 537.2.1.5 to ensure that all circuits are isolated,so it seems the main panel would need isolation alternatively the 3 circuits individually and at the same time would need this requirement every time local isolation was required,seems a cockeyed system to me

 

[Guest123]

If I understand you correctly, You have a DB external to building A, with 3 seperate circuits leaving this DB to each of the 4 buildings - A, B, C & D.

As long as each of these circuits has a correctly selected OCPD with any additional protection as required, and they are suitable to be locked off due to the extreme remoteness from the points of utilisation they supply I can see no reason why not.

As Des has mentioned though, earthing requirements need careful consideration to ensure dangerous potentials dont become present on extraneous steelwork/pipework under fault conditions.

 

[sedgy34]

all i can think of is if your in building B,C,D you have no local isolation

 

[Engineer54]

I think commonsense should be telling you, that there needs to be a form of isolation at each building, especially if these buildings are occupied. Now if that's not in the Reg's, ...then it dam well should be !!!

 

[pauljpickering8]

Thats my opinion, these are american electricians trying to work to british standard, each of the buildings is a wooden living area (8 separate rooms) there wanting to run 5 circuits to each building instead of just putting a single phase panel in each building, absolute joke. there will be 2 a/c circuits which will have double pole disconnects fitted, 2 radial socket circuits and a lighting circuit. in my opinion if there gonna re-wire 36 buildings they might as well do it correctly.

But this is afghanistan and there gonna do what they want, they'll probably start putting wire nuts in the trunking, some of the worst installs ive seen come from american sparks, and there square D QO panels....absolute disgrace

 

[Engineer54]

But this is afghanistan and there gonna do what they want, they'll probably start putting wire nuts in the trunking, some of the worst installs Ive seen come from american sparks, and there square D QO panels....absolute disgrace

I agree with your sentiments, some of the worst overseas electrical installations i've seen, have been installed by American, Filipino, and Korean Electricians, using NEC standards and American materials. I've stated many times on this and other forums, Yank MCB's etc are the absolute pit's as far as protection goes. Every fire and burnt-out building that i've come across overseas, have all been wired to the basic domestic NEC standards using there OCPD's along with every joint being made via their beloved wire-nuts!! (or as we used to call them ''screwits'') lol!!!

Come to think of it, i've never really seen a neatly installed American installation, it's normally a case of if it's to standard and works, it's a good-in!! lol!!!

 

[pauljpickering8]

I call them Fire Nuts, and they absolutely love them, who wires a new circuit, stops below the socket, puts wire nuts on the cable, unreal lol.

Makes me laugh when you open a Square D panel to switch a breaker off and when you do it pops off the busbar, laughable!!

The list is endless I could sit here and write a 3 page complaint lol

 

[Des 56]

I call them Fire Nuts, and they absolutely love them, who wires a new circuit, stops below the socket, puts wire nuts on the cable, unreal lol.

Makes me laugh when you open a Square D panel to switch a breaker off and when you do it pops off the busbar, laughable!!

The list is endless I could sit here and write a 3 page complaint lol

Are their standards really that bad?
If so, are their standards acceptable here as an alternative to our own,thats considering there must be many american residents living here with systems to their standard and their quipment that they are used to

The comments dont paint a good picture of their standards at all, and there's me with the impression that a British spark has to go through many hoops to get accepted over there

 

[Engineer54]

I just read one of your last posts again, ...Why would anyone run 5 circuits to each building from a single DB??

Are these circuits being run underground to each of these buildings?? The cost of all these branch circuit cables must be horrendous, let alone the physical work to install all these individual long circuits!! I would ask them to show you in the NEC codes where it Say's that local isolation isn't required for each of these branch circuits at these individual buildings. As i'm pretty sure it will call for them!!!

Why aren't they running small sub-mains to locally mounted CU/at these buildings, which would make far more sense, both electrically and for convenience, ...probably cost wise too!!...lol!!

 

[Engineer54]

Are their standards really that bad?
If so, are their standards acceptable here as an alternative to our own,that's considering there must be many american residents living here with systems to their standard and their equipment that they are used to

The comments don't paint a good picture of their standards at all, and there's me with the impression that a British spark has to go through many hoops to get accepted over there

Yes and No!! they have some really good points in there codes, but they also have some really antiquated set ups too, like there ''Multi-Branch'' circuits of either 3 wire single phase, or 3 phase + N. These are single point linked DP or 3 phase breakers for the phase conductors (not the neutral), that allows lighting and power to be taken from this set up, (eg, so could supply both 115V or 220V loads) using just a single neutral conductor from the panel/DB for all the circuits supplied by that breaker . You can just imagine the number of wire nuts on such circuits!! ...lol!!

 

[Guest123]

Closest I would say is 537.2.2.6, "Each Device used for isolation shall be suitably positioned OR durably marked such that the installation or circuit that it isolates is clearly identifiable".

Also, 537.2.1.5, "Where an isolating device for a particular circuit is located remotely from the equipment that it isolates, provision must be made such that the means of isolation can be secured in the open position. The securing arrangement and the procedures put in place for its release must be such that closing of the means of isolation is not possible until it is safe to do so. Where the provision for securing in the open position takes the form of a lock or a removable handle, the key or handle is to be non-interchangeable with any others used for similar purposes within the installation".

Also, it depends on what these circuits are actually for, i.e general lighting & power, machines etc.

I would agree that a single sub-main to each building from point A makes a great deal more sense but, technically there isn't a reg precluding multiple seperate circuits to each building.

 

[Engineer54]

Closest I would say is 537.2.2.6, "Each Device used for isolation shall be suitably positioned OR durably marked such that the installation or circuit that it isolates is clearly identifiable".

Also, 537.2.1.5, "Where an isolating device for a particular circuit is located remotely from the equipment that it isolates, provision must be made such that the means of isolation can be secured in the open position. The securing arrangement and the procedures put in place for its release must be such that closing of the means of isolation is not possible until it is safe to do so. Where the provision for securing in the open position takes the form of a lock or a removable handle, the key or handle is to be non-interchangeable with any others used for similar purposes within the installation".

Also, it depends on what these circuits are actually for, i.e general lighting & power, machines etc.

I would agree that a single sub-main to each building from point A makes a great deal more sense but, technically there isn't a reg precluding multiple separate circuits to each building.

This is basically what the OP is referring too with regards to the circuit numbers and there use... Basically it's for living quaters accomodation not storage sheds!!

Each of the buildings is a wooden living area (8 separate rooms) there wanting to run 5 circuits to each building instead of just putting a single phase panel in each building, absolute joke. there will be 2 a/c circuits which will have double pole disconnects fitted, 2 radial socket circuits and a lighting circuit. in my opinion if there gonna re-wire 36 buildings they might as well do it correctly.

Depending on the size of the A/C units (i'm guessing ''wall bangers''), 4 of them on each circuit, could end up being a sizable supply cable. ....Thank god for wire nuts!!! lol!! I don't think even a Electrical Trainee, would ever contemplate designing the wiring of these buildings in such a way.... It's a complete nonsense, and if our Reg's condone such an installation design, then there is something very very wrong!! lol!!!