Running Power to Shed - Advise Please?

[John2016]

Hello,

We live in a house which is 13 years old and I am getting a new 12 x 6 shed and base installed next week and I would like to run power to the shed for one and a dryer.

The run between the house and shed would be 15m in length. Next to the floor inside the house where the cable would terminate, I was planning to connect the Armoured Cable 3 Core 2.5mm cable to a 3 PIN Plug to the wall socket. Inside the shed I would have the cable connected to 2 Gang socket, one for a single light the other for the dryer in the future.

My house already has a RCD on the main fuse board, would I need another one for the shed power, should this be installed in the shed or in the house as the plug would be behind the cooker and difficult to get to?

Any views on this?

 

[EFLImpudence]

You cannot connect Armoured cable to a plug.

Outside power is not a DIY job.

 

[John2016]

Could I run a 2.5mm flex cable from the plug to a outside 'Weatherproof Outdoor Enclosure' and connect the armoured cable to the flex using wago connectors?

 

[John2016]

Or I could use a Wago box and connect the flex cable to the armoured core cable.

 

[chivers67]

No not really unless the SWA is terminated correctly then it will not meet regulations, as EFLI has stated this isn't really a DIY. Suggest you look on you tube

Consult an electrician, any SWA requires the Armoured part to be Earthed (at least one end best practice both ends) so needs to be terminated into an appropriate device/accessory/box.

 

[markyd1]

NO NO NO NO NO NO Get a sparky

 

[John2016]

So I have had someone round this morning and they want to charge £650 and want to run the armoured cable to the consumer unit which is at the front of the house, instead of taking a feed from one of the sockets in the kitchen.

The closest socket I have is for the oven which is connected via a 3 PIN Plug. As the shed will only have a tumble dryer at most, can I run extend the oven socket and connect the armoured cable inside the house with a 13A fused spur?

 

[oldbutnotdead]

You can run your shed via an FCU spurred off the kitchen circuit but it isn't a particularly good idea, especially if you have an electric cooker or other heavy loads on that circuit.
Why not ask the bunch who quoted to quote for your new idea? (It probably won't cost a lot less than doing the job properly, which is what they have priced for)

 

[John2016]

Its interesting as everything in the kitchen is off the same ring with only 6 gang panel switch without any fuses. At times we have washing, dishwasher and the oven on all the same time without any issues. Didn't think running a dryer would add much load on the circuit as if we can't install it in the shed we would end up installing it in the kitchen which would run from the same circuit.

 

[ericmark]

This is an old publication from 2005, however it will give you an idea as to what is required. I would agree not really a DIY job, but just saying that sounds as if we are looking for work for the trade, so hopefully once you see what is involved you will understand why we say not a DIY job.

A tumble dryer can be vented, or condensing or heat pump which is also condensing, and the load can be anywhere between 600 watt and 3000 watt, so we are looking at different problems depending on type. The regulations state

The load current in any part of the circuit should be unlikely to exceed for long periods the current-carrying capacity of the cable (Regulation 433.1.5 refers). This can generally be achieved by:
(iii) connecting cookers, ovens and hobs with a rated power exceeding 2 kW on their own dedicated radial circuit

since the kitchen is other side of house to consumer unit it seems unlikely this will be a problem, the quote is from BS7671:2008 which is old now, but time running is a consideration. And the tumble dryer can run for a long time, only the immersion heater runs longer, and we would not dream of running the immersion heater from anything else but a dedicated circuit.

The oven, washing machine, and dish washer also can draw near to 3 kW but not for very long, so we can likely get away running them off the ring final.

With the heat pump type, the problem is very different, yes it can run for hours, but at 500 watt not such a problem. However as with any refrigeration device be it a fridge, freezer, air con, or heat pump, volt drop can cause them to stall. Not so bad if they have an inverter drive, but other wise the loop impedance is rather important, this will to the trained person be converter into volt drop, which much not get lower than 207 volts. This allows for a 6% drop in the supply to house, and a further 5% within the house. If you get too much of a volt drop the unit will stall, and the overload will activate, however they are not designed to activate repeatedly, so will soon fail it volt drop is too high.

The major problem with DIY is the meters to check the loop impedance, and other parameters are expensive, looking at around £600, they can be hired, but since they need re-calibrating after each hire still expensive, around £80 for a week, and normally that's minimum hire time. That's assuming you know how to use the meters.

The problem for me is to work out what others can do. I have worked with SWA cable up to 270 mm² so 6 mm² is nothing, but as to how you can work with it is another question.

 

[chivers67]

So I have had someone round this morning and they want to charge £650 and want to run the armoured cable to the consumer unit which is at the front of the house, instead of taking a feed from one of the sockets in the kitchen.

Is that including all the Labour burying it and back filling etc or clipping it to a wall that does sound a tad expensive for one circuit but could well be a lot of work. How far is that run? Maybe get two more quotes but times ticking, so I'd perhaps put a duct in and rope it before the Shed goes down? If you did get a dedicated Feed it's future proofing it so it could be used for an office or similar and could be a good selling point.