Running power to robot mower from inside

[itfcjim]

Hi all

I've recently moved house and need to setup my robot lawnmower before the summer has been and gone!

I've got a socket in the kitchen that I'm sure we can run an outside socket from, but I could also just drill a hole under the socket to outside, put the cable through the wall, and plug it into an unused socket in the kitchen? My spidey senses are tingling that this might be a bad idea, so coming for reassurance that this will only look unprofessional, and isn't unsafe?

 

[Taylortwocities]

its a manky way to do it!

The socket outside must be of a suitable IP rating (it IS going to rain).

Safety - is the internal socket RCD protected? Any electrics outside must be protected by a 30mA RCD. this may be part of your fuseboard (consumer unit), or you can get plug-in ones.

You could buy a whole kit like this
http://www.diy.com/departments/diall-grey-switched-socket-prewired-plug/256536_BQ.prd

Or do the job properly.

 

[Doggit]

You're spidey senses are warning you that if you drill under the socket, you may hit an electrical cable. You need to ascertain where the cables are before you drill into the wall.

You may well have an RCD fitted on your fuse board, and if you use Taylors suggestion (a very good one mind you) then there's no guarantee that both RCDs won't go at the same time, but the beauty of Taylors idea, is that you don't have to mess around with the electrics trying to fit just the IP sockets outside.

You can do a neat job by drilling from the inside (once you know where the cables are), feeding the cable through the wall from inside, putting in a loop so that any water runs down the cable and not into the box, and then wiring up the cable inside the box to take out any excess cabling. Seal any holes with sealant, and you should have a nice job.

 

[ericmark]

I am thinking your looking at something like this

It does not say what the IP rating of the docking station is, but one would assume it is designed to be left outside 24/7, the most important thing is the RCD protection, and you want the RCD feeding the docking station to be able to trip without taking out the whole of the house, so either a RCBO in the consumer unit, or a 10 mA RCD which we hope if damp gets in will trip before the main house one

this does state 10 mA however not easy to find, my internet hunt shows they are made, but could not find one for sale.

So step one is find out how you will give it RCD protection, then worry about rest, last thing you want is the lawn mower stopping the fridge/freezer working. Since it is a fixture I see no problem in bringing the cable inside then fitting a plug or other connection, pointless having the weather proof socket, as it would always have the lid open for the device to be plugged in, so most would not be weather proof.

I did find an MK double socket K6211WHI but the rub is over £80 so that's why I say work out the RCD protection first then do the rest. 30 mA RCD's are cheap, 10 mA rather expensive. But as said you don't want to loose a freezer of food because lawn mower has tripped RCD.

 

[Taylortwocities]

pointless having the weather proof socket, as it would always have the lid open for the device to be plugged in, so most would not be weather proof.

The socket I proposed is designed to maintain its IP rating with the plug in and the cover closed - Unless i misunderstand what you are trying to say?

 

[ericmark]

The socket I proposed is designed to maintain its IP rating with the plug in and the cover closed - Unless i misunderstand what you are trying to say?

Sorry my error, but I am sure you can see my point, coming off a kitchen supply if not already RCD protected then easy enough, but if already protected to 30 mA then either you want a dedicated supply using a RCBO or a RCD at a lower rating, although 10 mA are made, they are expensive, and not easy to buy, normally you have to order it. There was a caravan supply shop who did plug in 10 mA at a reasonable price, but can't find it any more.
So it could be that you need a supply back to consumer unit to protect the freezer.

Yes I know there is no time discrimination so hitting the cable with lawn mower would not protect the freezer, but gradual ingress of water would likely trip the 10 mA before the 30 mA. With a standard lawn mower you are monitoring what it does, so tripping a RCD is not a problem you just reset it. But when running unattended then it's a whole different story.

 

[bernardgreen]

A lot depends on the quality of the docking station and its ability to resist water ingress. A 10mA RCD is likely to trip before a 30mA RCD trips if the earth leakage current increases slowly but it would need to disconnect both Live and Neutral to avoid the Neutral Earth leakage tripping the 30mA when the docking station get more wet and electrically leaky.

Peronally I would supply it from a dedicated circuit with its own RCBO on the consumer unit.

 

[Taylortwocities]

Which is a LOT more than the OP had in mind. You are talking new circuit, notification to the local authority, registered electrician, etc etc

 

[itfcjim]

Hi guys

Thanks for all of the posts, only just got round to doing this on my lunch break today. Ended up drilling a hole and running through one of those pre wired outside boxes as posted above (with RCD). Put sealant around the hole, mounted it, works a treat!

Point on tripping the freezer etc noted, just have to hope for the best on that one

Looks pretty neat too (and saved me a few quid). Thanks again

 

[winston1]

Hi guys

Thanks for all of the posts, only just got round to doing this on my lunch break today. Ended up drilling a hole and running through one of those pre wired outside boxes as posted above (with RCD).

So we can take it you don't already have RCD protection in your CU?

 

[itfcjim]

So we can take it you don't already have RCD protection in your CU?

It's a new build and all RCD'd, but thought an extra one for the outside wouldn't hurt?!

 

[winston1]

But as already explained, absolutely pointless. You will still have a freezer full of wasted food and two RCDs to reset instead of one.

 

[itfcjim]

But as already explained, absolutely pointless. You will still have a freezer full of wasted food and two RCDs to reset instead of one.

The socket I've put it on is on a separate RCD to the fridge freezer so no concern there, but you're right I've wasted a fiver on the plug in RCD, didn't think that through!

Cheers