Wiring Question

[stockonehundred]

Hi All,

I'm finally at the last point of getting my old Cooksley p/t up and running. Very exciting...

I'm putting a consumer unit in the workshop for the 16amp plug and also to tidy up the current set up. I'm crystal clear on everything except I'm not sure about which cable should come from the 16amp socket to the CU. Should I continue with 1.5mm arctic or 2.5mm T&E?

Thanks in advance.

 

[flying haggis]

If the 16a socket is to be fixed to surface i would use 2.5t+e from cu to socket

 

[Mike.S]

I'm no electrician so can't advise, except to say that I'm worried about that 1.5mm arctic (too small). It may be worthwhile to state what the cable length is and where (outside; underground; in conduit....etc) it's run e.g. 20m from house CU to workshop CU? Similarly it's best to state length of run and where (e.g. insulation reduces current carrying capacity of cable) and hopefully someone more conversant with current regulations can advise you.

 

[stockonehundred]

Thanks both. I'm using one of these so the socket is surface mounted. I'm curious to know why this would make a difference between the arctic and T&E

http://www.ebay.co.uk/itm/16-Amp-3-Pin- ... xyOlhS577I

The p/t is less than 5m from the socket. I'm running the cable up over head and across to the wall where the socket is and using 20mm conduit for the cable running to the CU.

Oh.... The cable running to the CU is 6m...

 

[Roughcut]

I'm certainly no electrician but I think 1.5mm is only rated to 13 amps.
So 2.5mm would be more suitable.

*Edit: I found this online: http://www.cable-ratings.co.uk/
1.5mm would be near the limit of current carrying capacity so 2.5mm looks to be right.

 

[stockonehundred]

It's definitely 16amps for arctic cable, but thanks...

 

[HOJ]

Use 2.5mm T&E, classed as fixed wiring, a 16A socket, or any socket, will handle current well in excess of its rated value, the cable will not.

Also need to add, comes under Building Regs Part P.

 

[stockonehundred]

Will do. Thanks all..

 

[Monkey Mark]

It's definitely 16amps for arctic cable, but thanks...

Yes but that is a maximum of 16amps. They are not intended to be pushed to the max at all times. And that is without taking into account any temperature related derating factors. Also, if you have type B rcd that would allow higher peak amperage.
I train Electrical installers and would never consider recommending 1.5 for running 16amp.

Edit: something else to consider. As the cable reaches its limit it will heat up, resistance will increase. This in turn affects voltage and current. (ohms law) If running a motor, this may have a detrimental effect in the long run.

 

[mindthatwhatouch]

Can I suggest a socket that has an Isolator with it or next to it, much easier to switch an isolator off than try and unplug it, particularly if you are in a hurry.

 

[n0legs]

For clarity.
Arctic cable commonly comes in two sizes and therefore two ratings.
2.5mm CCC 25 amps
1.5mm CCC 16 amps

:arrow: OP
Are you intending on using flex as fixed wiring?

 

[YorkshireMartin]

Just in case you didn't know, because I certainly didn't when I looked at doing it...performing such an installation yourself, unless you're certified, would actually be illegal these days due to the part P regulations, perhaps building regs also. The law changed a few years ago, which makes it a criminal offense.

Not trying to be a smart alec, consider it a friendly heads up.

 

[stockonehundred]

I stand corrected. I'll be using 2.5mm for the 16 amp plug.. I'm using flex for the plug to the socket and 2.5mm T&E for the fixed wiring. Thanks for the concern, I'm getting a spark to sign it all off. I'm not bonkers!!

 

[tomf]

Just in case you didn't know, because I certainly didn't when I looked at doing it...performing such an installation yourself, unless you're certified, would actually be illegal these days due to the part P regulations, perhaps building regs also..

Don't think so Part P is notifiable under building regs and building regs will fall under a civil action but nothing to do with the law.

Anyone can carry out Part P work as long as they are 'competent' you will however need to get building control in to ok the install if the person installing it can;t self notify.

 

[YorkshireMartin]

Just in case you didn't know, because I certainly didn't when I looked at doing it...performing such an installation yourself, unless you're certified, would actually be illegal these days due to the part P regulations, perhaps building regs also..

Don't think so Part P is notifiable under building regs and building regs will fall under a civil action but nothing to do with the law.

Anyone can carry out Part P work as long as they are 'competent' you will however need to get building control in to ok the install if the person installing it can;t self notify.

Correct, I should have said "are able to certify or get someone to certify the work". I discounted the latter as I cannot imagine that anyone with a part P would certify such work unless they installed it themselves? They'd have to be mad. Also, I think a lot of electricians are covered for Part P only on company time, so wouldn't be able to help in such circumstances. Then again you have kitchen fitters who've done a short course and got part P and thus can do work a qualified electrician can't, so who knows. I spoke to 5 electricians. I'd bought the parts myself which they said was fine, but they said they would not issue a certificate on the consumer unit unless they installed it. To me that makes sense due to insurance and so on.

The other issue was, to connect a CU in the garage required a new MCB in the household CU. This apparently requires the removal of the electricity company fuse to the mains or something, which apparently the electricity company has to do as it's their property.

About the legal thing. If such work (in this case a new circuit) cannot be proven as certified, it is actually a criminal offence. So yes, it's not doing the work thats criminal, it's having it uncertified. Hence I felt it worth saying, as people may wrongly assume this type of stuff is a slap on the wrist type deal.

Personally, after my brief brush with it, I think Part P implementation is a total shambles and I feel sorry for qualified electricians in this regard.

Anyway no intention of doing the grandmother and eggs thing, just something I found out recently in similar circumstances and felt it worth sharing.

 

[James-1986]

How big is the motor and how big is the block? You will have a big surge from a DOL start, but when the block is up to speed it will draw pipper all. If you're planning on running the planer at full capacity for extended periods then it is better to over compensate on the wiring. I'd probably go with the cooker cable, its cheaper than the flex!

 

[Lons]

This is what I power my table saw from which I feel is safer than the type you show. originally I used the cheaper one but wasn't happy with it really though it worked ok. The switch on this locks in and plug can't be inserted or withdrawn unless off.
http://www.ebay.co.uk/itm/16A-3-PIN-240 ... 3f333d1a5e

Bob

 

[tomf]

This apparently requires the removal of the electricity company fuse to the mains or something, which apparently the electricity company has to do as it's their property.

It is generally accepted that it is ok to remove the main fuse and cut any tags, what the supplier does not like is if the meter tags are removed.

 

[stockonehundred]

Well it's all done and everything working just fine. I didn't need to change the switch in the CU in the house because it's a 32a with 4mm SWA running into it. Incidentally, I did turn off the main power into the house to disconnect the live wire in the workshop switch. Not sure why you would think the electricity board need to do this, it's perfectly safe and allowed... All the sockets are running off 16a switches with 2.5mm t&e (I used heat proof flex for the p/t plug). I considered using 4mm flex/t&e so I could put 32a switches in the shop to allow more things running at the same time, but I would have had to upgrade the SWA and the switch in the CU in the house. The switch wouldn't have been a problem, but the SWA would have been a big job. As it is, it's ample to run the table saw and extractor with lighting, radio, dehumidifier for the drying room and if I want it the heater. The p/t has a dedicated 16amp switch so there's no overload from that. Nothing will overheat, it will just trip because none of the breakers are too high for the cables. They're all protected from this. I have an electrician coming to sign it all off on the proviso I have all sockets, plugs and CU open and ready for inspection. Thanks again for all the input. Time to get stuck into the p/t. Happy days...