Size of SWA cable

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Hi,
I have been asked to install an armoured cable to connect a greenhouse to the existing 16A supply in an outhouse.
I will lay the cable and wire up splashproof sockets and light fittings for their electrician to check and connect to supply.
I intend using 2 core cable with the steel armour as the earth, the cable length is 45 metres.
Could someone please recommend suitable spec for cable.
Many Thanks.
 
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I have been asked to install an armoured cable to connect a greenhouse to the existing 16A supply in an outhouse. I will lay the cable and wire up splashproof sockets and light fittings for their electrician to check and connect to supply. I intend using 2 core cable with the steel armour as the earth, the cable length is 45 metres. Could someone please recommend suitable spec for cable.
Since (s)he will be checking, connecting, approving and 'certifying' the work (and, probably, by implication also 'designing' it), you really need to find out what cable the electrician would want to be used.

We could give suggestions, but it might then be that the electrician was not happy with what cable had been used - so you then could have to start again!

Kind Regards, John
 
Hi, 4mm at 45m would give a 9.39 Volt Drop and 17a max load.
I would use 3 core , one core for earth.

2.5mm has a VD of approximately 11v.

Regards,

DS
 
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Hi,
I have been asked to install an armoured cable to connect a greenhouse to the existing 16A supply in an outhouse.
I will lay the cable and wire up splashproof sockets and light fittings for their electrician to check and connect to supply.
I intend using 2 core cable with the steel armour as the earth, the cable length is 45 metres.
Could someone please recommend suitable spec for cable.
Many Thanks.

Asked by who?
 
Asked by my customer. Why are you so interested?

Just curious why someone would ask a non electrician to do some electrical work. Presumably you're a handyman business?

Anyway, make sure you're aware of the requirements for buried cables in terms of trench depth and preparation and marking tapes. Assuming it is a buried cable of course.

You need to get your customers electrician to size the cable, and think about the earthing requirements, and to agree with your method and routing of the installation. They will want to inspect the cable before its buried.
 
Hi, 4mm at 45m would give a 9.39 Volt Drop and 17a max load.
Can you explain what you mean by "17A max load". 4mm² SWA will obviously take much more than that, although it's only a 16A circuit, anyway.
I would use 3 core , one core for earth.
For what it's worth, so would I - but it seems that there are polarised, and often strongly held, views about that!

Kind Regards, John
 
Thanks for that Simon.
Yes, I am a handyman.
There is a stone wall running alongside for most of the length. As I understand the regs it is acceptable to run the swa cable above the ground surface correctly cleated along the base of the wall.
Would you concur?
 
Personally I'd use three core - one for the earth as mentioned and also earth the armoured at both ends with a banjo strap.

Fine to clip the armoured onto the wall. When it disappears underground at least a spade depth (some say two deep) with electrical warning tape immediately on top of SWA
 
Personally I'd use three core - one for the earth as mentioned ....
As I've said, so would I, but ....
... and also earth the armoured at both ends with a banjo strap.
Whether or not the armour was 'earthed' at both ends would depend upon how the electrician decided to deal with earthing in the greenhouse.
Fine to clip the armoured onto the wall. When it disappears underground at least a spade depth (some say two deep) with electrical warning tape immediately on top of SWA
Unless you have an unusually big spade, 'one spade depth' would be inadequate in terms of any guidelines I am aware of. However, from what the OP has said, it is not clear that any of the SWA is necessarily going to be buried.

Kind Regards, John
 
Thanks for that Simon.
Yes, I am a handyman.
There is a stone wall running alongside for most of the length. As I understand the regs it is acceptable to run the swa cable above the ground surface correctly cleated along the base of the wall.
Would you concur?

Don't see a problem with clipping to a wall.

The electrician may decide to earth the greenhouse using spikes into the ground local to the greenhouse, called TT, and just bring live and neutral out on the armoured cable. The armouring would then only be connected to earth at one end.
 
Asked by my customer.
Your customer?

How dare you take money from people to carry out a service which you are demonstrably incompetent to perform?

Who is going to sign these, with credibility:

I being the person responsible for the design of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design, hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2015 except for the departures, if any, detailed as follows:

I being the person responsible for the construction of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the construction , hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2015 except for the departures, if any, detailed as follows:

Because you can't.
 
As I've said, so would I, but ....
Whether or not the armour was 'earthed' at both ends would depend upon how the electrician decided to deal with earthing in the greenhouse.
Unless you have an unusually big spade, 'one spade depth' would be inadequate in terms of any guidelines I am aware of. However, from what the OP has said, it is not clear that any of the SWA is necessarily going to be buried.

Kind Regards, John
Hence the reason I underlined at least

Kind regards Chivers
 

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