Outdoor sockets

[Bruspark]

As others have said.  Double pole switch fuse (13A) to protect and isolate, correctly rated SWA down the garden and have one 2KW and one 1KW heater ! 

If that’s not good enough you need to cable right back to the consumer unit 

 

[Bruspark]

Murdoch, I fully understand the maths thank you. Not every heater is exactly pulling 8.6amps because they say it on the paper. I will try and if it trips fine. 

For a small overload the most likely result is long term overheating of cable and/or accessories rather than an abrupt disconnection.  
I’m not sure why you’re happy with this ... 

 

[boltonsparky]

Fuses don't blow at close to their rating for a very long time if at all, the worst thing you can do is just slightly overload a fuse. If you're out there all night with a couple of heaters plugged in at 4kw the 13a fuse is going to take forever to blow, you'll melt the fused spur first, very common to come across melted/damaged fused spurs when they're running loads close to 13a never mind just over, running 4kw of heating through it so it's going to get hot. 

 

[Sharpend]

1) why is it too difficult to run a cable to main consumer unit? 
2) what’s the point in spending money on a setup that isn’t going to work? 
3)are you really going to put people at risk as overheating can cause fires, you might be out in the garden but your partner/kids may not? 
 

id suggest that you really sit down and talk with ourself about what’s important to you. 
 

then if you conscious speaks back - take notice. 
 

I would also suggest that a little more input from other local sparks would be wise, just because you or your existing spark doesn’t see another option doesn’t mean someone else won’t? 

 

[SPECIAL LOCATION]

Since no one has objected to 2.5mm cable, I am

assuming it is ok.

I think your assumption is incorrect..

and didn't read my earlier post.. 

With regard to your question about 2x 2kw heaters it is impossible to answer as you haven't given us the full circuit characteristics or loading of the existing circuit..

WHAT exactly does the existing circuit supply?

How long is the circuit?

What is the spec of the current protective device?

How close to the max permissible earth loop impedance will the amended circuit be?

etc..

You appear to assume every time a fault occurs a fuse trips and you just re-set it...

(Bit like assuming the only fault you get with a car is a flat tyre.. way to simple)

There are numerous other symptoms that overloaded circuits can cause..

such as damage to insulation on a parts of the circuit that is difficult to access causing earth leakage and inability to reset RCD's..

Damp, ingress into poorly installed external components can allow continuity between earth & neutral..

which with prevent any RCD supplying that circuit from being reset..

IF you have multiple circuits sharing that RCD.. you will lose power to more than just your garden..

Wiring regulations requires circuits to be designed to minimise inconvenience in the event of a single fault.

and as  3kw immersion heaters regularly cause overheating faults to 13A rated spurs..

so 4kw worth of heaters on top of whatever else the circuit is already supplying is bad design in my book.

 

[kerching]

Wiring regulations requires circuits to be designed to minimise inconvenience in the event of a single fault.

And that folks is why dual RCD boards do not comply with the regs!

eeeeeeey thank. Yowwwwwwwwwwwwwwwww

 

[Murdoch]

And that folks is why dual RCD boards do not comply with the regs!

eeeeeeey thank. Yowwwwwwwwwwwwwwwww

I came across a recently updated board recently. 
 

single up front RCD - WTGrape

 

[binky]

there is another option if taking a cct back to the Consumer Unit is not possible. Spur off socket in 4mm, and take it to a mini board (IP rated) with isolator switch and 20A MCB, then run sockets in 4mm SWA. You coukd use 2.5mm SWA, but it's  along run for that and based on a guesstimated total run if 50m the Doncaster cables calculator suggests 4mm, XLPE cable for 4 kW at that length. 

 

[Murdoch]

there is another option if taking a cct back to the Consumer Unit is not possible. Spur off socket in 4mm, and take it to a mini board (IP rated) with isolator switch and 20A MCB, then run sockets in 4mm SWA. You could use 2.5mm SWA, but it's  along run for that and based on a guesstimated total run if 50m the Doncaster cables calculator suggests 4mm, XLPE cable for 4 kW at that length. 

That doesn't comply with BS 7671 and anyway the OP says he has a spark involved .......

 

[binky]

That doesn't comply with BS 7671 and anyway the OP says he has a spark involved .......

why not?

 

[MikeYardleyPro]

Ok chaps, calm down. I have no intention to short cut anything and go for an unsafe route. I am even prepared to cancel the work as I written before. For handful of nights I will use the heaters, it is just not worth the headache. 
I went for an electrician with 40+ years experience and still there are questions about his judgment. 
how will trust an electrician if you cannot agree among yourselves? I see this in the other threads as well. 
I will consult to a second electrician and see what he says. 

thanks everyone for their replies so far. I like to understand and learn what is done in my house. 

 

[binky]

Ok chaps, calm down. I have no intention to short cut anything and go for an unsafe route. I am even prepared to cancel the work as I written before. For handful of nights I will use the heaters, it is just not worth the headache. 
I went for an electrician with 40+ years experience and still there are questions about his judgment. 
how will trust an electrician if you cannot agree among yourselves? I see this in the other threads as well. 
I will consult to a second electrician and see what he says. 

thanks everyone for their replies so far. I like to understand and learn what is done in my house. 

There are as many opinions are there are sparks! The regs have always had many grey areas that can be interpreted in different ways by different people. I've never heard of anyone 'ringing' a garden before, it is a bit of an odd option in my opinion, but that doesn't mean it's wrong. Provided it meets the max Zs values for the circuit, and has suitbale RCD protection etc etc, then that is the ultimate critria.

For garden heating I much prefer wood burner of some sort, but then I spent a lot of time in the Scouts cooking on wood fires. Wood is considered carbon neutral, so 'greener' option, and you can cook marshallows on sticks  

NB, we like a discussion or two  :slap

 

[kerching]

can cook marshallows

And make dough with SR flour and lemonade, wrap around a green stick and bake

 

[boltonsparky]

The good old sausage on a stick, burnt black on the outside, raw on the inside.

A good one we used to do was a frying pan on a fire (no need for it to be on a fire, just because), jam sandwich dipped in batter and then fried.

 

[Murdoch]

40 years experience BUT how up todate with the regs is he? Experience AND up to date quals = good

Theres a chap around here still working to the 16th Edition 

 

[SPECIAL LOCATION]

I went for an electrician with 40+ years experience and still there are questions about his judgment. 
how will trust an electrician if you cannot agree among yourselves? I see this in the other threads as well. 
I will consult to a second electrician and see what he says. 

thanks everyone for their replies so far. I like to understand and learn what is done in my house. 

Indeed there are..  and it was you that raised the questions...

There is actually significant agreement about various aspects...

While others will be open to interpretation.. 

as for any proposed work there are often multiple solutions that can be applied... 

some more practical than others..

Some less desirable, with dubious compliance to current regulations. (BS7671)..

And some positively dangerous!!

Basic rule for these situation is get at least two, preferably three independent quotations for the proposed works.. 

 

[binky]

And make dough with SR flour and lemonade, wrap around a green stick and bake

used to do that in the scouts, but not with lemonade. Very simple, and delicious with loads of butter and jam on them. 

 

[kerching]

used to do that in the scouts, but not with lemonade. Very simple, and delicious with loads of butter and jam on them. 

Found it out when they had a "dads and lads. Scout camp

never sure if it was that or the copious amount of alcohol that made me ill, possibly a dirty glass