Wiring garage sockets with steel conduit, how do I do this?

[timbim]

It's true that there are plenty of dangerous DIY'ers asking questions that can sound similar to that asked above, there are equally plenty of dangerous cowboys calling themselves electricians. For that reason I like to understand the process a reputable professional would use in a given situation so I can then question them based on that in the quoting discussion. If they want to do something different, I can ask them why they chose that method over the one I propose. From the nature of their reply, it's usually pretty apparent how competent they really are.

If I don't know enough to ask sensible questions when they're quoting, then I'll ask to find out. Makes sense to me.

 

[shagster]

It's true that there are plenty of dangerous DIY'ers asking questions that can sound similar to that asked above, there are equally plenty of dangerous cowboys calling themselves electricians. For that reason I like to understand the process a reputable professional would use in a given situation so I can then question them based on that in the quoting discussion. If they want to do something different, I can ask them why they chose that method over the one I propose. From the nature of their reply, it's usually pretty apparent how competent they really are.

If I don't know enough to ask sensible questions when they're quoting, then I'll ask to find out. Makes sense to me.

Exactly, the other problem you get is what I call 'Quote fatigue'. Say you get three electricians round, you get a description of the work they plan to do, one says he'll do XYZ checks that the other one says are not strictly necessary. You hear from all of them and it's all subtly different, even if the socket positions and so on are all the same. Then you go away and inevitably do your own research to decide between them, you post on forums like this to check which of these is the best way to go, then you get back to all of them to adjust their quotes. Of course, the time taken to provide that second quote is always substantially longer than the first. Tradesmen are generally not stupid - there's no hurry to give you an adjusted quote 'cos you start to smell like a time-waster. The more quotes you ask for the more you have to hassle people to come up with them whereas if you knew exactly what you wanted in the first place you bypass all that stuff, and just get three straight quotes.

The other area where knowing the job helps is if you prefer to hire an electrician on a day rate. You can have all the bits purchased in advance, which may suit them by reducing the likelihood they go over the VAT threshold. You just pay for the work done, and pay them to come back and fix it if there are any matters arising. Can work out cheaper because they always have to increase the price of a quote slightly to deal with the unexpected. Also, if people aren't rushed they tend to do a better job.

regards,
S.

 

[RF Lighting]

Well it's simple.

Say to your electricians I want 4 sockets in these positions. You could draw some crosses on the wall if you want.

Say I would like the drops from the ceiling in steel conduit, and the rest of the wiring above the ceiling out the way.

I want a circuit capable of supplying 32A

Here is my fuse box. (point at it as you say that)

Then you get three quotes back.

Which ever price you and tradesman you feel most happy with give the job to.

Easy peasy.

Oh and let the sparks supply all the materials. They will be able to buy it cheaper than you can, and they will get everything they need, and brands they are happy to install, and in the event that something goes faulty, it is up to them to replace it.

 

[riveralt]

I have to say that the contents of your posting has really become quite bizarre the longer you have gone on and I’m wondering now whether you are just a troll in disguise or practicing to become the customer from hell.

In your first post you outline that you want a ring of garage sockets and then proceed to provide a detailed statement of how you want the steel conduit run around the garage house T&E leading to metal sockets - without any real evidence to justify such an approach.

I advised you that the first thing you needed to was decide what you were going to use the sockets for. This is critical for a number of reasons not least it will determine circuit type, cable size, MCB type and size and whether there is a need for additional protection be that steel conduit (which by the way will double the cost of installation) or RCD. You have not responded to this.
I told you that your existing installation will also need to be considered when designing the new or additional circuit. You have not responded to this.

You then seem to believe that every electrician is out to rip you off and that if you do not have as much knowledge as the electrician then that will be the case.

Your problem is that in trying to gain this knowledge you haven’t answered the questions that have been put to you. Instead you have picked up bits of accurate and inaccurate information that seem to be confusing you. To the extent that you have developed a fixation on steel conduit and the need to ensure a copper earth while ignoring the fact that your proposals create many other issues that should cause you more concern. What do you mean by the benefits of ring current on any socket?

Slapping your head rolling your eyes and blaming this forum for not highlighting the potential problem posed by the issues of spurs simply raises the hackles of people genuinely trying to help you.

As for buying the parts and paying me by the hour – no problem (hourly rate £20 – daily rate £140) – I won’t guarantee the parts – I will still be paid if you fail to get the right parts and as you’re the paying customer if you want steel conduit you can have it (even if you don’t need it) – just make sure you hire the pipe bending kit as well.

As for requesting a second quote – I think if a customer started playing those games most electricians would walk – indeed most would have walked by now if you insisted on the above anyway.

So good luck on your endeavours, I just pity the poor electrician who winds up working for you.

 

[SimonH2]

You could draw some crosses on the wall if you want.

That is no guarantee With a customer at work we needed a new supply in to feed a rack of computers. The boss from the electricians doing the job came round, I drew a rectangle on the wall where we wanted the double socket, etc, etc - and then his lad fitted it somewhere else. So there's this rectangle with an X in it on one side of the rack, and the socket on the other.
Luckily it doesn't matter since it would need an extra 4 feet of cable on a an SWA cable that runs about 50 feet to the nearest DB.

But back to the OPs question. Unless you have really demanding requirements (in which case you might question using "13A' sockets at all), then I'd have thought plastic conduit would be more than adequate. You can easily get 2x2.5mm T&E cables down a straight piece of 20mm round conduit, and it will mate to your metalclad boxes with the right bushes.
If you do insist on metal conduit, then I'd have thought the cables will still fit. You'll need a bush on the top to prevent it cutting into the cable sheath & insulation - they make a short female-thread bush which will screw directly onto the conduit and provide a nice smooth end. Whoever does the work will need threading gear - a lot don't these days as there's little call for metal conduit outside of industrial environments (and even a lot of those use plastic).

 

[RF Lighting]

Just be done with it and slap one of these in your garage like I did

 

[Alarm]

Its crooked.

 

[RF Lighting]

What is?

 

[Alarm]

Your site outlet box, or was you leaning over when you took the pic

 

[RF Lighting]

I think it's just the picture. I wouldn't be able to bear it not being level

 

[Adam_151]

You used to be be able to get 2.5mm² 6242Y with stranded conductors (definatly wasn't old 7/.029 , seen it on many jobs much more recent than the metric changeover)

It pulls into conduit easier than solid, and was often used on school jobs etc, where the ring would run on a tray above a suspended ceiling and drop down conduit to a surface socket.

 

[ban-all-sheds]

Tradesmen are generally not stupid - there's no hurry to give you an adjusted quote 'cos you start to smell like a time-waster.

Why do I hear what sounds just like the voice of experience there?

Sorry, shagbrain - there's nothing you can say now to counter the image of a complete w**ker who thinks that he really can go to electricians and ask them to quote against a spec like this:

"I want you to start with T&E in the ceiling, then Bonding nipple, straight coupler then screwed nipple, taking T&E into tee box where you transition to the flexible with a choc block, then down the conduit to the socket with the flexible, then back up to the tee box again, another choc block, back to T&E out the other tee exit, screwed nipple, straight coupler, another bonding nipple taking me back to T&E, through a few joists and on to the next drop."

 

[shagster]

Sorry, shagbrain - there's nothing you can say now to counter the image of a complete w**ker who thinks that he really can go to electricians and ask them to quote against a spec like this:

If I get to be classed as a w**ker simply 'cos I offended your sensibilities about what I should and shouldn't ask on a forum, then happy to be whatever you say. I'd say the w**ker was the guy who throws insults into a thread where there weren't any, but that's just the way I was brought up.

"I want you to start with T&E in the ceiling, then Bonding nipple, straight coupler then screwed nipple, taking T&E into tee box where you transition to the flexible with a choc block, then down the conduit to the socket with the flexible, then back up to the tee box again, another choc block, back to T&E out the other tee exit, screwed nipple, straight coupler, another bonding nipple taking me back to T&E, through a few joists and on to the next drop."

Is there some rule that says I have to send the exact same text, as typed into a forum to the electrician I'm getting the quote from? Hey, maybe I should send the whole thread (including your insults) just to make sure I never get a quote ever. Yeah, that'd be really smart. Who gives a t*** what I'm sending to get quotes, I wasn't asking how to request a quote, I was asking about the job.

 

[shagster]

I have to say that the contents of your posting has really become quite bizarre the longer you have gone on and I’m wondering now whether you are just a troll in disguise or practicing to become the customer from hell.

Bizarre perhaps, because you are an electrician and I am not and we are not speaking the same language. So what? If I spoke with broken English would you also call me a troll?

In your first post you outline that you want a ring of garage sockets and then proceed to provide a detailed statement of how you want the steel conduit run around the garage house T&E leading to metal sockets - without any real evidence to justify such an approach.

So, why can't I throw an example of the way I'm thinking (as a layman) into the quote. What crime was committed there?

I advised you that the first thing you needed to was decide what you were going to use the sockets for. This is critical for a number of reasons not least it will determine circuit type, cable size, MCB type and size and whether there is a need for additional protection be that steel conduit (which by the way will double the cost of installation) or RCD. You have not responded to this.

OK, I'll respond now - thanks, I need to consider it. I hadn't decided yet what I wanted to use the sockets for, that's why I hadn't responded, because I don't yet know. Or did you want me to respond with "I'm thinking about that"? Seemed a little pointless.

I told you that your existing installation will also need to be considered when designing the new or additional circuit. You have not responded to this.

Because the CU is to be upgraded, and I haven't decided to what. I don't know, nothing sinister, and I'm not trying to p*** anyone off by not responding.

You then seem to believe that every electrician is out to rip you off and that if you do not have as much knowledge as the electrician then that will be the case.

Well, not really. Actually the opposite. Electricians, unlike builders for instance, all seem to quote similar amounts.

Your problem is that in trying to gain this knowledge you haven’t answered the questions that have been put to you. Instead you have picked up bits of accurate and inaccurate information that seem to be confusing you. To the extent that you have developed a fixation on steel conduit and the need to ensure a copper earth while ignoring the fact that your proposals create many other issues that should cause you more concern.

Fair cop. I like the idea of the steel conduit in the garage. I think it'll look nice. I think it'll look professional as well as be secure. Anyone looking at it will think more 'industrial' than 'domestic', and that's the reason why I want it. It isn't just about practical considerations. Sorry I didn't make that clear before.

What do you mean by the benefits of ring current on any socket?

Again a language problem perhaps? I mean the current that flows both ways round the ring, from the source meeting at the appliance socket can presumably be double what it would be on a spur. It's got two routes, therefore twice the area of copper, assuming the wire that goes to the CU is twice the capacity, or it joins to the CU in two places. I'm just showing my ignorance, I don't know the technical term for this increase is, I just said 'ring current', but I apologise for using the term.

Slapping your head rolling your eyes and blaming this forum for not highlighting the potential problem posed by the issues of spurs simply raises the hackles of people genuinely trying to help you.

OK, point taken. Sorry.

As for buying the parts and paying me by the hour – no problem (hourly rate £20 – daily rate £140) – I won’t guarantee the parts – I will still be paid if you fail to get the right parts and as you’re the paying customer if you want steel conduit you can have it (even if you don’t need it) – just make sure you hire the pipe bending kit as well.

The daily rate is very reasonable but that's not really what I'm asking in the thread.

As for requesting a second quote – I think if a customer started playing those games most electricians would walk – indeed most would have walked by now if you insisted on the above anyway.

The customer doesn't always request a second quote just to annoy people, or 'play games'. It can be that they got the original quote request wrong because they didn't know enough at the time. What do they do then? Ignorance doesn't make someone the big bad wolf.

So good luck on your endeavours, I just pity the poor electrician who winds up working for you.

Why? He will walk away from the job with no requirement to guarantee his work in any way (other than providing a bit of paper that satisfies the council). If he has to come back to fix anything he got wrong he'll be paid for that work. He won't have to worry about the price of copper (or anything else) changing between quoting and doing the work. Sounds like a pretty good deal to me.

 

[comms]

I do garages in the manner you are on about, drops from ceiling to sockets are conduit, at ceiling end I use a male conduit adaptor to save any chaffing of cable.

no need for the junction box at the ceiling/conduit drop point, if you are using 2.5mm T/E it will fit in a straiht drop of 20mm conduit , or you could use 25mm coduit for more room.

you can as you've said wire as a ring final at 32A in 2.5mm T/E or as a radial at 16A or 20A in 2.5mm T/E

Or you could wire in a radial ciruit using 4mm T/E at 32A.

If cost isnt an issue & you being the customer, it's upto you what you want installed, but pvc conduit & pattresses are fine for most domestic workshop/garages.