Cable rating - domestic

For any general chat and banter.

Moderators: scimjim, Lukeyboy46, erikscimitardemon, Roger Pennington, philhoward

User avatar
Coupe Racing
RSSOC Member
Posts: 7558
Joined: Mon Jul 23, 2007 10:51 pm
Location: Nr Telford - Shropshire
Has thanked: 31 times
Been thanked: 125 times

Cable rating - domestic

Post by Coupe Racing » Mon Nov 18, 2019 8:24 am

Hi a question about 3 core single phase wiring rating please ?

I would like to run armour cable from my house to my garage .
There is already old cable above ground but I want to start from scratch and bury armour cable
The garage runs 7 double 13A sockets , 14 six foot fluorescent tubes.
I occasionally run a welder that is marketed as 150A.
The distance from supply to fuse box will be approx 40m

Not sure if I need 2.5mm or 4mm armour cable .

Many thanks
Steve


Blessed are the Cheese makers

Better to be an hour early than 1 minute late

Dave 6726
RSSOC Member
Posts: 490
Joined: Wed Dec 27, 2006 3:07 pm
Location: Northumberland
Has thanked: 54 times
Been thanked: 15 times

Cable rating - domestic

Post by Dave 6726 » Mon Nov 18, 2019 9:09 am

If I were doing it, 4mm. You know your own usage patterns, but if I had that size of workshop I might even consider 6mm. May be considered over-engineering, but you could install it and forget it.



User avatar
peter freeman
RSSOC Member
Posts: 10396
Joined: Thu Aug 31, 2006 12:12 pm
Location: Newcastle
Has thanked: 9 times
Been thanked: 417 times
Contact:

Cable rating - domestic

Post by peter freeman » Mon Nov 18, 2019 9:11 am

I used a poly water pipe to run the cable in to keep the water out - go for 4mm rather have too much capacity than too little - the 150amp will be at 50 volts not mains supply of 240 volts



User avatar
philhoward
RSSOC Member
Posts: 26579
Joined: Tue Aug 29, 2006 5:41 pm
Location: Staffs, UK
Has thanked: 102 times
Been thanked: 803 times
Contact:

Cable rating - domestic

Post by philhoward » Mon Nov 18, 2019 9:19 am

What's your upstream breaker (on your consumer unit) for this circuit - 16A or 32A?

2.5mm will just about do the job (depending on how it's buried - direct, in pipe/conduit or an open trench), but if going to the trouble of putting a cable in then put 4mm as there's nothing worse than volt drop issues - especially with welders.


Phil Howard
Scimitarweb Forum Admin
SS1 1600 Rooster Turbo; Sabre Mk1.5, Sabre Mk2
Previous: SE5/5a/SS1 No.1/SS1 Rooster/SS1 1800Ti/SE5a 24 Valve
SS1 Racer
http://www.ss1turbo.com
Never try and argue with an idiot. They drag you down to their level, then beat you based on experience.

tony1966
Posts: 146
Joined: Sun Jul 21, 2019 11:10 am
Has thanked: 10 times
Been thanked: 6 times

Cable rating - domestic

Post by tony1966 » Mon Nov 18, 2019 11:47 am

you can help on the lighting load by using led strip lights-very low consumption,cheap to buy too if you order from the far east



willholderogri
RSSOC Member
Posts: 1173
Joined: Sat Aug 21, 2010 10:47 pm
Location: chippenham
Has thanked: 213 times
Been thanked: 46 times

Cable rating - domestic

Post by willholderogri » Mon Nov 18, 2019 12:11 pm

4mm or 6mm your choice ( I would use 6mm ) fluorescent are low current so no real need for led as they are pricy at he moment. I have 15 fluorescent in five banks of three no problem even with a welder and compressor as long as you don't run them together.


1962 mini, bedford CA , KR200. morris 1000, mini pickup.several escorts,ford grandad.ford cortina X2 ,astra, SE5A x 2 ,ford focus.

User avatar
David Tew
RSSOC Member
Posts: 711
Joined: Sun Aug 06, 2006 11:09 am
Location: Cotswolds
Has thanked: 24 times
Been thanked: 68 times

Cable rating - domestic

Post by David Tew » Mon Nov 18, 2019 12:57 pm

SWA is the stuff you need. 40 metres is a fair old run so I'd definitely use 6mm minimum, especially if it's buried as you'll need to downrate it. I presume you have a CCU in your garage and I'd ensure the RCD for the sockets is rated at 20A to protect the SWA. This will be fine for the ring as long as you don't plug everything in at once!

I use TLC for my electrical bits. Good quality and rarely beaten on price. They even have a handy cable-size calculator HERE.

I must admit I always use LED battens now as they use much less power and this might be important in your installation. They are more expensive though so it's personal choice really.

Have fun. :wink:


- My wife says I don't listen to her ...... or something like that! -
SE4B Coupe - rebuilt on brand-new chassis.
Bought in 1978 and an RSSOC member since. 😲

willholderogri
RSSOC Member
Posts: 1173
Joined: Sat Aug 21, 2010 10:47 pm
Location: chippenham
Has thanked: 213 times
Been thanked: 46 times

Cable rating - domestic

Post by willholderogri » Mon Nov 18, 2019 5:25 pm

I have an led Batton in my hobby room and it's fantastic so much light it makes it ideal for working on my electronic
projects .


1962 mini, bedford CA , KR200. morris 1000, mini pickup.several escorts,ford grandad.ford cortina X2 ,astra, SE5A x 2 ,ford focus.

cookieboy
RSSOC Member
Posts: 2828
Joined: Sun Aug 07, 2011 5:10 pm
Location: northfleet kent
Has thanked: 20 times
Been thanked: 28 times

Cable rating - domestic

Post by cookieboy » Mon Nov 18, 2019 5:37 pm

Shop around for prices .6mm 3 core is more common than 4 mm and buy a 50 metre drum as the wholesalers price by metres and charge for cutting in most cases.


Currently scimitarless .

Sabreite
RSSOC Member
Posts: 59
Joined: Fri Jun 11, 2010 11:23 am
Location: Sussex
Been thanked: 2 times

Cable rating - domestic

Post by Sabreite » Mon Nov 18, 2019 8:28 pm

David Tew wrote:
Mon Nov 18, 2019 12:57 pm
SWA is the stuff you need. 40 metres is a fair old run so I'd definitely use 6mm minimum, especially if it's buried as you'll need to downrate it. I presume you have a CCU in your garage and I'd ensure the RCD for the sockets is rated at 20A to protect the SWA. This will be fine for the ring as long as you don't plug everything in at once!

I use TLC for my electrical bits. Good quality and rarely beaten on price. They even have a handy cable-size calculator HERE.
I agree with David when I put the electric into my garage/workshop I used 6mm armoured cable underground, I also ran a ring main with plenty of double sockets, in 4mm twin and earth to make sure the welder had enough power. The only problem is fitting the larger copper cable into the 13amp sockets it’s doable but not the same as installing 2.5mm cable. Also if you are going underground put the yellow warning tape (caution electric cable below) a few inches above the cable in the trench saves a problem in later years. I get all my bits from TLC they are very good on price and quality.

John



User avatar
scimjim
RSSOC Member
Posts: 39491
Joined: Sun Oct 01, 2006 10:08 pm
Location: Gloucester
Has thanked: 167 times
Been thanked: 1169 times

Cable rating - domestic

Post by scimjim » Mon Nov 18, 2019 8:56 pm

I have dedicated blue 16/32A Commando sockets for the compressor, tyre machine and welder, you could wire them in 4mm - and run a separate 2.5mm ring main for household 3 pin sockets and lighting?


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

User avatar
Coupe Racing
RSSOC Member
Posts: 7558
Joined: Mon Jul 23, 2007 10:51 pm
Location: Nr Telford - Shropshire
Has thanked: 31 times
Been thanked: 125 times

Cable rating - domestic

Post by Coupe Racing » Wed Nov 20, 2019 10:44 am

Thank you to all who replied via PM and the forum.
To be safe and to future proof I will use 6mm

Thanks again


Blessed are the Cheese makers

Better to be an hour early than 1 minute late

User avatar
Coupe Racing
RSSOC Member
Posts: 7558
Joined: Mon Jul 23, 2007 10:51 pm
Location: Nr Telford - Shropshire
Has thanked: 31 times
Been thanked: 125 times

Cable rating - domestic

Post by Coupe Racing » Sun Mar 08, 2020 1:22 pm

Just a Quick revisit now I have got round to doing this.

Should I order 2 or 3 core ?


Blessed are the Cheese makers

Better to be an hour early than 1 minute late

User avatar
philhoward
RSSOC Member
Posts: 26579
Joined: Tue Aug 29, 2006 5:41 pm
Location: Staffs, UK
Has thanked: 102 times
Been thanked: 803 times
Contact:

Cable rating - domestic

Post by philhoward » Sun Mar 08, 2020 1:43 pm

Using 2 core relies on using the armour as earth so personally I’d use 3 core - known as single phase 3 core so the colours are correct.


Phil Howard
Scimitarweb Forum Admin
SS1 1600 Rooster Turbo; Sabre Mk1.5, Sabre Mk2
Previous: SE5/5a/SS1 No.1/SS1 Rooster/SS1 1800Ti/SE5a 24 Valve
SS1 Racer
http://www.ss1turbo.com
Never try and argue with an idiot. They drag you down to their level, then beat you based on experience.

User avatar
Coupe Racing
RSSOC Member
Posts: 7558
Joined: Mon Jul 23, 2007 10:51 pm
Location: Nr Telford - Shropshire
Has thanked: 31 times
Been thanked: 125 times

Cable rating - domestic

Post by Coupe Racing » Sun Mar 08, 2020 1:55 pm

ok - just wanted to make sure - thank you


Blessed are the Cheese makers

Better to be an hour early than 1 minute late

Post Reply

Return to “Non-Technical Discussion”