Discuss Armoured cable size in the DIY Electrical Advice area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

Reaction score
2
Hi, having a granny a erected in my garden and doing a lot of the the work myself.
Looking to run a armoured cable feed into the anex so it's already for electrician to eventually wire up my question is as follows.

Works out as 25m run I'll need from where sse feed in is to fuse box location in anex.

Circuits in new board will be a 11kw water heater so 50amp breaker, 9 sockets so a 32amp ring main and 3 florescent strip lights 6 amp which to me works as max potential of 88amps... Know chances of drawing 32 amps from ring isn't going to happen but due to distance etc am I potentially looking at 16mm core armored or worse 25mm core armour.

Thanks, any more info needed
 
Hi, having a granny a erected in my garden and doing a lot of the the work myself.
Looking to run a armoured cable feed into the anex so it's already for electrician to eventually wire up my question is as follows.

Works out as 25m run I'll need from where sse feed in is to fuse box location in anex.

Circuits in new board will be a 11kw water heater so 50amp breaker, 9 sockets so a 32amp ring main and 3 florescent strip lights 6 amp which to me works as max potential of 88amps... Know chances of drawing 32 amps from ring isn't going to happen but due to distance etc am I potentially looking at 16mm core armored or worse 25mm core armour.

Thanks, any more info needed
Best advice get an electrician to design the complete installation, what calculations have you done to arrive at your choice of SWA.
Your annex will require bonding as there will be water pipework to consider, as extraneous metalwork, arbitrarily guessing the size of feed is a silly option.
 
You need to involve an electrician at this stage to design the job. Design is part of the certificate to be signed at the end of the job. The forum can't sign that bit so we shouldn't be designing it.
 
You need to involve an electrician at this stage to design the job. Design is part of the certificate to be signed at the end of the job. The forum can't sign that bit so we shouldn't be designing it.
I understand that, and would make sense...
Not looking at installing anything, purely laying the armour into the ground whilst the gardens ripped up.

Gave specs of granny anex to purely state what the maxiumum load would be, looking to save money by getting armour In ready for future connection.... To me personally, makes no sense to have a sparky come out and lay the cable in the ground when I can do that part myself...
Seems like a waste of money and time
 
Laying in the cable would be installing it. Buying the cable would involve sizing it which is design.
I would contact a local electrician and get them to size the cable through their design of the job, you seem to have a good grasp of the required electrical load so this is already helpful for them. Explain you want to install the cable and I'm sure that will be fine. They will even be able to tell you how to install it correctly and in compliance with regulations.
A lot of electricians will be happy for customers to do menial tasks like this, but if you do it the other way round, lay the cable then call someone in, most will be a lot less interested in the rest of the work.
 
Also, this work falls under Part P, so you need to inform your local authority building control. This will be a lot cheaper if the electrician does this rather than you.
 
i go with Andy78's advice. spot on. and spoon deserves a slice of cheesecake for his post.
 
Ahem, maybe my own love of cheesecake has not been vocalised enough .....
 
Why hasn't anyone ever given a prefered cheesecake? There are so many to choose from. You wouldn't want to end up with one you don't like would you.
 
funny thing is cheesecake. if hitler had been given some decent cheesecake, maybe he would not have invaded Poland.
 
Thanks guys will get in contact with a sparky and see what he can design etc.
Just wanted to be prepared and slightly knowledgeable in what might be required.

Ie will a 100amp main breaker see feed be enough to handle the potentially load of anex and house, or might I be looking at having to get a new sse feed put in.

Sorry just want to prepare myself for worst possible scenario, imagined it would be to get anex up and running, but more thought and advice I'm getting seems like it might be a nightmare lol.

Thanks for everyone's help, most appreciated
 
Best advice get an electrician to design the complete installation, what calculations have you done to arrive at your choice of SWA.
Your annex will require bonding as there will be water pipework to consider, as extraneous metalwork, arbitrarily guessing the size of feed is a silly option.
No bonding required Pete if all done in plastic which seems to be the thing with domestic these days. depends upon if the building is of metal construction.
 
my first thought would be to ditch the 11kW water heater. get something less powerful. have you considered getting gas to the annex?
 
No bonding required Pete if all done in plastic which seems to be the thing with domestic these days. depends upon if the building is of metal construction.
I did say, Ant "CONSIDER" the pipework's need for bonding, you are right of course, IF the pipework was plastic, however as the OP didn't say what sort of pipework was to be installed, we weren't to know. I was trying to point out that arbitrarily picking a cable size from thin air, is rather silly, again that there may be a need for bonding, which seems to have been overlooked.
 
I understand that, and would make sense...
Not looking at installing anything, purely laying the armour into the ground whilst the gardens ripped up.
Either get the electrician to design the correct size cable so that you can install it or put a duct in both should be at a suitable depth with warning tape.
 

Attachments

  • forum.pdf
    2.1 MB · Views: 10
I understand that, and would make sense...
Not looking at installing anything, purely laying the armour into the ground whilst the gardens ripped up.

Gave specs of granny anex to purely state what the maxiumum load would be, looking to save money by getting armour In ready for future connection.... To me personally, makes no sense to have a sparky come out and lay the cable in the ground when I can do that part myself...
Seems like a waste of money and time
Is this all a pre-made pod installation?
 
Either get the electrician to design the correct size cable so that you can install it or put a duct in both should be at a suitable depth with warning tape.
if fitting a duck, make sure there's a draw string in it,
 
my first thought would be to ditch the 11kW water heater. get something less powerful. have you considered getting gas to the annex?
Agreed. That’s the killer. Better to install a small Megaflo with an immersion heater. Demand then plummets from 10kw to 3KW.
You’ll still need a big cable for that distance.

PS don’t worry about the 100A main switch. The DNO fuse may be a lot less than that (do you know if the existing supply is even big enough??)
There’s so many basic things to consider. Suggest u just lay a 50mm twin wall service duct and leave the rest to an expert.
 
I did say, Ant "CONSIDER" the pipework's need for bonding, you are right of course, IF the pipework was plastic, however as the OP didn't say what sort of pipework was to be installed, we weren't to know. I was trying to point out that arbitrarily picking a cable size from thin air, is rather silly, again that there may be a need for bonding, which seems to have been overlooked.
If he is using a minimum of 16mm 3 core then he is ok regarding the minimum size assuming it is a 100A S.P. domestic supply
 

Reply to Armoured cable size in the DIY Electrical Advice area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock