40A Supply In Garage

[Andy™]

so basically youre god of electrics and can do anything else because its easier than what you do now? well if it was that easy you wouldnt need to ask what flex to use to make an extension lead

 

[jamal6008]

Jamal,

You can and could have got a lot more information if you had come to the party with a different attitude.

You are not the only Engineer who has been on the forum.

The level of answers you get are based on the way you post the question.

The readers have no idea what you are trying to do, nor your competence.

If you want help you must explain yourself correctly.

Same could be said about everyone else here. My attitude was very much fine but guess what made it change?? All the replies from everyone else telling me that I have no competance or knowledge or anything else. At first I thought fair enough they don't know me so I can't expect them to know what I know. This is when I introduced myself but things only got worse since then with more and more questions directed at questioning my education/experience rather than solving problem at hand. Anyways, Its probably best for all of us if we end this discussion here. Thanks to people who helped me with this in any way. I do not intend to give up on this in any way and once I have completed this wiring I will make sure to come back here and post some pictures. 

 

[Andy™]

 with some proper design & planning, there are other potentially easier options available... and i doubt im the only one who has already thought of them... however that is not something you can learn in an hour asking a few basic questions on a forum...

 

[jamal6008]

 with some proper design & planning, there are other potentially easier options available... and i doubt im the only one who has already thought of them... however that is not something you can learn in an hour asking a few basic questions on a forum...

You are right. I didn't come to the forum to learn everything there is to know in few hours. I came here so that someone can point me in the right direction so I can then go and do my own research and see what I can come up with and come back here and talk about it. This is how you learn. Its a feedback process. I don't even know why I thought that an electrician forum would be the place to get some help.  

 

[Sidewinder]

Well jamal I have to disagree with your attitude, in my opinion you should have come "clean" in the first place.

You then choose to IMHO avoid questions about whether you are experienced in the works you are proposing, and you don't confirm the topics you have studied for your degree.

So what are we going to think?

 

[apprentice87]

Hi Jamal,

"How will I install the cable? Is that supposed to be a tricky question?"

It is a serious question.. See, when you select a cable, the problem is, there is no such thing as a "40A" or any other capacity cable. That is its tabulated capacity, but you must apply all sorts of correction factors for things like how the cable is installed, [duct tray clipped direct etc] insulation round or on it, is it run with other cables, ambient temperature and stuff like that to come up with the ACTUAL current capacity. You need to be checking volt drop and R1 + R2 for the circuit to work out what Zs will be and will it be low enough for your selected OCPD..

Anyway, you need to split the tails with Henley blocks and then use these to feed your isolator/OCPD for the cable. A switch fuse would be best. What TYPE of cable were you thinking of using to feed the new socket?? For your extension you definitely need HO7RN-F like this stuff http://www.nexans.co.uk/eservice/UK-en_GB/navigate_300462/LINEAX_H07RN_F.html

What earthing system does your house have????

Please do not think people are being awkward.. There is MUCH more to this than you realise.. What testing equipment do you have???

john..

 

[New Venture!]

Em......can I just ask a question?

Isn't the Clarke compressor you mentioned a three phase unit?

 

[jamal6008]

Em......can I just ask a question?

Isn't the Clarke compressor you mentioned a three phase unit?

Not the one I am getting. They come in both three phase and single phase units. I am getting single phase one.

 

[New Venture!]

Ah, just wondered. I installed one in a workshop but it was the three phase job.

 

[jamal6008]

Hi Jamal,

"How will I install the cable? Is that supposed to be a tricky question?"

It is a serious question.. See, when you select a cable, the problem is, there is no such thing as a "40A" or any other capacity cable. That is its tabulated capacity, but you must apply all sorts of correction factors for things like how the cable is installed, [duct tray clipped direct etc] insulation round or on it, is it run with other cables, ambient temperature and stuff like that to come up with the ACTUAL current capacity. You need to be checking volt drop and R1 + R2 for the circuit to work out what Zs will be and will it be low enough for your selected OCPD..

Anyway, you need to split the tails with Henley blocks and then use these to feed your isolator/OCPD for the cable. A switch fuse would be best. What TYPE of cable were you thinking of using to feed the new socket?? For your extension you definitely need HO7RN-F like this stuff http://www.nexans.co.uk/eservice/UK-en_GB/navigate_300462/LINEAX_H07RN_F.html

What earthing system does your house have????

Please do not think people are being awkward.. There is MUCH more to this than you realise.. What testing equipment do you have???

john..

Thanks John for your help I understand that cable hasn't got a fixed rating which pretty much applies to cables around the whole electricity industry but when I said 40A cable I meant cable that will be able to handle the capacity that I want in the situation. It strickly will not be 40A tabulated cable it will definitley be higher than that. As you rightly said this will depend on many factors. Cable wise 3-core 10mm^2 should be sufficient? Earthing system is PME. I got earth loop impedance testing device among few other things. I will have a look at henley blocks and switch fuse.

Ah, just wondered. I installed one in a workshop but it was the three phase job.

Yup they do a lot of variants and there are only two of them that are single phase supply.

 

[apprentice87]

Hi Jamal,

Got to rush out, but will comment tomorrow, Earthing might be interesting......

john...

 

[Sharpend]

John you've missed last orders!!

 

[Sidewinder]

Not where I am !

 

[steptoe]

Not where I am !

Nor me,

Are you at the 3steps Inn,? 

PME, as a DNO operative, then surely you are aware that you cannot 'export' this type of earthing without explicit consent from the DNO, which they are highly unlikely to give. 

 

[Doc Hudson]

Hi

I have an existing socket in garage but I presume that these are normally rated at 13A? Also the wiring mostly likely won't be able to handle 40A? What is the easiest/cheapest way to get a 40A socket in garage?

I can think of a few ways of re-writing the whole thing but that will be a long job and will cost a bit. Any suggstions are welcome.

Thanks for the help.

jamal, Welcome to the forum, I would just make an observation that the comment in your opening post about presuming what the current rating of a standard domestic socket is, does suggest someone who is not qualified or competent to undertake the type of work you are referring to. I myself would find it hard to believe that any person qualified to a reasonable level of electrical understanding has no knowledge of basic 3pin sockets and their maximum fuse ratings. As such I can fully understand the doubts and questioning by other members as to your abilities. I am sure you would agree it would not be good practice to guide someone out of their depth to undertake work that has clear dangers due the the loading of the circuits being discussed.  There are numerous threads in the archives of the forum where people completely out of their depth are asking questions about DIY work that could be potently lethal. Hopefully you can understand and put into context some of the replies that you received from the limited information that you gave. The forum will always try to assist genuine questions in a polite and friendly way, But lack of information in some questions can imply a significant danger to someone well out of their depth of understanding and ability.

Doc H.

 

[col]

Are we seriously comparing a simple house wiring to the complexity of 132-400kV systems?

so telecoms should be a piece of cake? & alarms, child's play?

I hope you call in a spark, but I really wouldn't tell him what you think of his industry!