Greenhouse And Shed

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DIYShock

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Hello!  Just as a way of introduction as I'm a newbie on this forum, I am a DIYer but have a relatively sound though basic understanding of wiring and would consider myself to have at least a little common sense.

I am installing a small supply from a radial main in the garage to a greenhouse and shed which are within 10 meters of the garage wall.  The entire supply is RCD protected at the CU.

I have used 1.5mm 3 core SWA at a depth of at least 300mm - it's going to be under 3" concrete for most of it's run outside and have placed the warning tape on top.

The intention is to supply a single socket in the greenhouse (using an IP66 socket) and a double socket in the shed (IP55 double socket) for use with mowers and blowers, greenhouse fan heater etc.  Unlikely that all will be in use at once and certainly don't see the supply ever reaching 13A.

1) If I attach the cable to a 13A plug and plug it into a garage socket, do I need to have it checked under Part P, since it is outside wiring, though essentially just a buried extension cable?  (If nothing else, Diall seem to sell kits to specifically allow a DIYer to do this!)

2) Is it reasonable (though I assume Part P checkable) to connect the supply to the end of the garage radial main (Which currently has 3 sockets running very little off them)?

3) If I wire up the greenhouse and shed plugs, but leave the internal garage connection, would a professional be happy to connect the cable, test it, and part p sign it, or does it not work that way?

4) (and Finally) Can an IP66 socket be mounted on the floor (socket holes pointing to the sky) or would I need to make a little stand for it to sit as if it were in a wall (the greenhouse itself isn't strong enough for a socket to be attached)?

Many thanks for your help and sorry to ask yet another outside wiring question - I see there are many, but I can't find an answer to these questions.

Regards

 
I have used 1.5mm 3 core SWA at a depth of at least 300mm - it's going to be under 3" concrete for most of it's run outside and have placed the warning tape on top.

The intention is to supply a single socket in the greenhouse (using an IP66 socket) and a double socket in the shed (IP55 double socket) for use with mowers and blowers, greenhouse fan heater etc.  
1.5 cable would be a bit shy for socket use.

*Edit* Sorry, forgot you use 13 Amp sockets so you might just get away with it depending on length and installation method. Is your SWA cable standard PVC insulated?  

Is the garage radial directly from the CU or is it taken from a ring circuit in the house?

 
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There is sooooo much wrong with what you have done/planning that if you called me to look at it I'd recommend ripping it out and starting again..

SWA is not meant to be connected by a plug

600mm is the recommended depth of burying

Like Marvo has said 1.5mm probably up to supplying a socket

and finally an IP66 socket shouldn't be mounted on the floor in a potentially wet environment

 
1) If I attach the cable to a 13A plug and plug it into a garage socket, do I need to have it checked under Part P, since it is outside wiring, though essentially just a buried extension cable?  (If nothing else, Diall seem to sell kits to specifically allow a DIYer to do this!)
I can't believe there's a kit available that allows you to put a plug on an SWA cable. How do you connect the armour strands to the CPC? Can you give a link to this kit please? 

After re-reading your opening post it sounds like there's going to be several sockets supplied via this SWA cable. Rather use a fused isolator and proper SWA glands with earth rings to connect in the garage otherwise you're going to overload this cable.

 
Marvo, Thanks for the quick response.

1.5 cable would be a bit shy for socket use.
 At the point of sale (and yes, sadly I am working slightly backwards having bought the cable and buried it) this was recommended to be enough for running a lawn mower or a heater.  The intention for the cable is simply a tidier extension lead really.

*Edit* Sorry, forgot you use 13 Amp sockets so you might just get away with it depending on length and installation method.
You managed to edit this whilst I was thinking "but I thought 1.5mm was rated to 16A"!  Anyway, the length of SWA from garage wall to greenhouse is approx. 2m and from greenhouse to shed will be approx. 4m.  The greenhouse to shed will actually be above ground so heat dissipation will be better as well.  Inside the garage I will do the usual gland onto junction then standard 3 core to either plug, socket or CU (if essential). 

Is your SWA cable standard PVC insulated?
The SWA is "PVC sheathed, XLPE insulated to BS5467".

Is the garage radial directly from the CU or is it taken from a ring circuit in the house?
The garage radial is directly from the CU.  The CUs (yes, there is more than one, and Solar feed in to complicate things) are actually in the garage along with the main supply.

Thanks for your help


 
There is sooooo much wrong with what you have done/planning that if you called me to look at it I'd recommend ripping it out and starting again..

SWA is not meant to be connected by a plug

600mm is the recommended depth of burying

Like Marvo has said 1.5mm probably up to supplying a socket

and finally an IP66 socket shouldn't be mounted on the floor in a potentially wet environment
NozSpark.  Thanks for your comments.

The only thing I have done so far is lay a cable - so I think it would be a little drastic to suggest ripping it up - you, Marvo and the sales assistant have all said it should be fit for purpose.

I know SWA is not to be connected by a plug.  However, if you connect SWA to a junction box then a 3-core from the junction to the plug would that be workable?

As far as 600mm, I believe that depends on the location.  I understand the 17th ed states it must be deep enough to avoid disturbance by routine use of the ground - 400mm under concrete and 600mm under flower beds is suggested, but there is no written rule.  The only must as far as I was aware was that there must be warning tape above the cable - which there is.  The depth is certainly great enough that no one is going to disturb it through routine gardening!

Thanks for the confirmation that IP66 shouldn't be floor mounted.  That's what I wanted to know, so thank you.

Any further help would be gratefully appreciated.

 
I can't believe there's a kit available that allows you to put a plug on an SWA cable. How do you connect the armour strands to the CPC? Can you give a link to this kit please? 

After re-reading your opening post it sounds like there's going to be several sockets supplied via this SWA cable. Rather use a fused isolator and proper SWA glands with earth rings to connect in the garage otherwise you're going to overload this cable.
Marvo,  Sorry but it seems like I misled you slightly.  In my defence I hadn't looked in detail at the kits, only saw them in passing.  Anyway, one is here: www[DOT]diy[DOT]com/nav/fix/electrical/switches-sockets/-brand-Diall/Diall-Power-Kit-3M-JB-5M-2G-SKT-RCD-12608735 (do change the [DOT] - I'm too new to post links!)

It is not actually SWA as I thought (looking at the picture) though there is no reason why it couldn't be since they do use the IP66 rated socket and a junction box at the supply end.  The cheap cable could as easily be replaced with SWA.

I have indeed got the correct SWA glands ready, and yes, I agree that a fused isolator at 13A (assuming you are referring to something like [DOT]diy[DOT]com/nav/fix/electrical/switches-sockets/metal-clad-switches-sockets/Volex-Switched-Connection-Unit-Metal-Clad-12758741

 ) seems a good plan.  Although of course, if I connect to a 13A plug then that is (in effect) a 13A fused isolator!

Any more help would be gratefully received.

 
Mine in red

NozSpark.  Thanks for your comments.

The only thing I have done so far is lay a cable - so I think it would be a little drastic to suggest ripping it up - you, Marvo and the sales assistant have all said it should be fit for purpose.don't trust a sales assistant,,, they are usually just that and have very little if any electrical training - however 1.5mm might be OK, but then again it might not and the only way to truly know the answer would be test what you are connecting it to

I know SWA is not to be connected by a plug.  However, if you connect SWA to a junction box then a 3-core from the junction to the plug would that be workable?That would depend on what type of box and how you connect it

As far as 600mm, I believe that depends on the location.  I understand the 17th ed states it must be deep enough to avoid disturbance by routine use of the ground - 400mm under concrete and 600mm under flower beds is suggested, but there is no written rule.  The only must as far as I was aware was that there must be warning tape above the cable - which there is.  The depth is certainly great enough that no one is going to disturb it through routine gardening!Your right, but 300mm isn't really deep enough where the ground might be dug over as a garden fork can easily go to that depth

Thanks for the confirmation that IP66 shouldn't be floor mounted.  That's what I wanted to know, so thank you.

Any further help would be gratefully appreciated.
 
NozSpark,

Thank you for the clarification.  I know what you mean about sales assistants.

I was intending on using an IP55 junction box e.g. www[DOT]diy[DOT]com/nav/fix/electrical/switches-sockets/outdoor-switches-sockets/junction_boxes/Diall-Small-Junction-Box-12608730 with the appropriate glands.  Then either a 3 core to connect to the garage radial or a 3 core to connect to a plug, depending on whether I can do either with/without Part P...

The 300mm is only under the concrete.  The depth was at least 400mm under the soft ground, but down the side of some steps anyway in an area that nothing is going to grow and was well into the clay level.  I think it is probably okay, though I appreciate your thoughts and know opinion differs.

Many thanks

 
Well as of the 6th April it's not Part P notifiable anyway, so good luck with it all.
Steve, thanks for this.  I had seen mentioned briefly on a different forum that it was no longer Part P notifiable, but with no explanation I couldn't find the changes.

I believe - from my reading of the Part P document on gov[.]uk that technically the work is covered by Part P (i.e. it is electrical work) but as long as it doesn't involve a new circuit to the CU it is not notifiable and doesn't need to be done by an electrician.  Therefore in answer to my original 4 questions:

1) This doesn't seem to apply anymore, though even when plugged in via a 13A plug it is under the remit of Part P, just non-notifiable

2) It should be acceptable to connect to the current garage radial which is directly taken from the CU as long as the CU MCB is of an appropriate amperage and the cable is appropriately rated.

3) Technically before April 6, no an electrician could not have connected my work and certified it.  However now they technically can, but there isn't yet an agreement on who would be licenced to do this!

4) From NozSpark's comments, an IP66 socket shouldn't be floor mounted.  However, reading the IP ratings, and since I have found IP66 floor mounted sockets available for purchase, I understand that IP66 means its International Protection (IP) rating is completely sealed to dust (6) and powerful water jets from *any direction* (6).  It wouldn't be suitable for immersion (7) but then when does the floor of a greenhouse become an immersed environment?  So my understanding is that there is nothing preventing floor mounting technically, just a decision about the environment.  Is there actually anything against floor mounting it, or were you thinking that there is a great potential for a very wet environment in a greenhouse NozSpark?

Hope this is helpful for anyone reading this topic in the future..., so please do correct me if I've made incorrect assumptions.

And just to clarify the location - the work is in England, which is neither a mammal nor a fish!

Many thanks for all your help!

 
Is there actually anything against floor mounting it, or were you thinking that there is a great potential for a very wet environment in a greenhouse NozSpark?
Well,, if you think about it,,,,,,

What is the environment within a greenhouse?

You have soil/compost and plants,,,, which all need watering either by a watering can or hose pipe.... and you will also have quite high humidity levels.

Now, where will any of the soil go if it gets spilt??

Where will any excess water go if it gets spilt?

Just a few thoughts!

P.S. I have quite a background with greenhouses,,, my parents were market gardeners in my youth with nearly a 1/2  acre under glass/polythene

 
I'm not entirely sure ANY outside socket really CAN have an IP66 rating.

It's the "water jets from ANY direction" bit that bothers me.

A 13A socket is only of any use if you can plug a 13A plug into it.  So it must have an opening lid.

I'm guessing that the supposedly IP66 one, is a type that allows you to shut the lid while a plug is plugged in.

But you still have the flex exiting a hole between the lid and the body, hopefully "sealed" by some form of soft rubber seal that closes around the cable.

Now, if you think that socket is going to be okay lying on it's back, then you are putting 100% trust in that seal actually keeping the water out for good and not letting ANY in, to run into the socket pins.

Fine when it's mounted upright, but I would say no to lying it on it's back. 

 
What tester have you got mate? I hope your not bang testing it
Why not, would you advise otherwise??  And test it for what?  Overheating? Live connected to Neutral? Earth failure? CU/RCD/MCB functioning correctly?  Helpful advice is always appreciated but I couldn't extract much information from your comment.

Well,, if you think about it,,,,,,

What is the environment within a greenhouse?

You have soil  compost and plants,,,, which all need watering either by a watering can or hose pipe.... and you will also have quite high humidity levels.

Now, where will any of the soil go if it gets spilt??

Where will any excess water go if it gets spilt?

Just a few thoughts!

P.S. I have quite a background with greenhouses,,, my parents were market gardeners in my youth with nearly a 0.5  acre under glass/polythene
NozSpark, thanks for the comments.  I was curious as to the reasoning behind your advice not to floor mount it.  I can understand where you're coming from but as long as the water can drain away, surely something that can withstand a 1bar (at 3m) 1/2inch jet of water at 100 litres water per minute can probably withstand some water from a standard garden hose or watering can.  Isn't this the purpose of it being IP66 rated?  Anyway, I will take onboard your advice and experience, and will probably mount it upright anyway.  If nothing else, the screw-holes in the back must cause a reduction in the IP66 rating if it is on its back (or a set of drainage holes....  )

I do appreciate your time and advice everyone, and when I eventually get chance to do this, I will feel that I am at least following the right path.

 
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