Armoured Cable and Power Supply to Scope

[AlistairW]

Hello,

In a quest to always minimise set up time I have a pier in the middle of my small garden with a 10m distance to an outdoors 240V supply. Currently I simply run a 10m bog standard extension lead from the pier to the junction box, which I unroll and roll up every session.

What if I were to buy a 10m of 3 core armoured cable, put a plug on one end and a socket on the other - essentially just the current extender with but made with an armoured cable - then, burry the cable under the lawn. This would create a permanent supply to the scope.

Couple of points, the junction box (I think) is connected to a RCD via the fuse box in the house (the house was only built 2 years ago). Also I think that cable should be buried to 0.6m depth, however I am not intending on wanting to go much below a spades depth, as only a rotary lawn mower would skim across the surface, and I would know where the cable is anyway.

Does this at all sound safe or a recipe for electrocution ?

Thanks

Alistair

 

[Davey-T]

Sounds like you should hire a qualified sparks then if you or anybody else gets electrocuted you can blame him 

Dave

[D4N]

I think outdoor sockets don't need to be on the RCD so you may not be protected by that.  Easy test is to trip the RCD and see if there is still power on it.

I have run armoured cables under my lawn but both ends terminate at a junction box rather than sockets.  In areas where it s near the surface protection is increased with some metal pipe.

[Jon the Newb]

Personally, I think you're taking a substantial risk here in terms of liability.  The problem iis that (as Dave put it) you can't guarantee someone else isn't going going to come across it for whatever reason.  It could be the next homeowner digging in the yard, someone you hire for yard repairs down the road, etc... it's easy to forget you have a buried cable there, and it's not worth someone getting electrocuted.  

 

Either bury it it the proper depth of the local regulations there, or don't do it.  That's my advice..?

[AlistairW]

Good advice, hadn't thought that there would be regulations regarding this. Think it might be a job for professionals. Looks an easy thing to do, but the consequences of getting it even slightly wrong make it not worth the risk I think.

[iapa]

I seem to tremor that changes in the past 5 years or so to regulations mean that you now need a qualified electrical engineer to install external power sockets

[D4N]

I think the proposal in the first post wouldn't come under that as it is technically just an extension lead buried in the ground not an actual socket.

[RayD]

ALL outside works, including shed supplies have to be Part P certified now, so you will legally have to have this done by an electrician who is registered for Part P.

[AlistairW]

Thanks for the advice. Glad I asked now, - not something I will try now. Will look to professionals I think.

[ngwillym]

Actaully, this is a moot point.

If the original outdoor socket was installed before Part P became required - then that's OK - no need for Part P. So just using an extension lead (i.e. something that is not a permanent fixture) - i.e. with a plug to plug into the outdoor socket and a socket at the other end to attach an 'appliance' (i.e. scope) shouldn't require certification - otherwise anyone using an extension lead for their garden tools is breaking the law? 

Does it matter if the 'extension lead' is a) armoured and b ) buried in the ground.

Discuss?

Neil

[RayD]

1 minute ago, ngwillym said:

Does it matter if the 'extension lead' is a) armoured and b ) buried in the ground.

Yes it does as it's not a temporary lead i.e. anything that is fixed, which would include burying, is a permanent installation.

Look it's up to the OP, but I don't think we should be advising on "technicalities" where it could lead to electrocution, which is precisely the reason Part P was introduced.  The reason they were introduced and specifically mention outside services, was that this is area most likely to kill you if it all goes wrong.  The question posed clearly identifies the OP is not qualified in this department (no offence, but that is fairly clear) so the sensible advice is get an electrician to do it.

 

[RayD]

Believe me I get more frustrated than most.  I recently renovated my elderly Mother's bungalow, and am a qualified electrician (albeit 16th edition so would need to update my qualifications), but couldn't do any of the works as I'm not Part P registered, so had to pay a sparks and watch him doing what I could very easily have done myself.

[Davey-T]

Used to be CORGI registered many years ago but gave it up when it became a money making racket, we would get "qualified" people in to do stuff but they generally made such a pigs ear of it we ended up redoing it after they'd gone.

I failed to see how going to college and fitting a boiler onto the wall in the same place a hundred other people had fitted it with all the services handily placed in any way qualified someone to fit boilers.

Similar with the electrics courses, I see peeps on "Homes Under The Hammer" TV prog' saying "i've done all my own electrics because I went on the course"

Had a qualified sparks on one of our jobs who fitted a new split consumer unit and couldn't figure out way the breaker kept tripping until we pointed out to him that he had a live in one half and the neutral in the other half.

Dave

[RayD]

1 minute ago, Davey-T said:

Used to be CORGI registered many years ago but gave it up when it became a money making racket, we would get "qualified" people in to do stuff but they generally made such a pigs ear of it we ended up redoing it after they'd gone.

I failed to see how going to college and fitting a boiler onto the wall in the same place a hundred other people had fitted it with all the services handily placed in any way qualified someone to fit boilers.

Similar with the electrics courses, I see peeps on "Homes Under The Hammer" TV prog' saying "i've done all my own electrics because I went on the course"

Had a qualified sparks on one of our jobs who fitted a new split consumer unit and couldn't figure out way the breaker kept tripping until we pointed out to him that he had a live in one half and the neutral in the other half.

Dave

You're absolutely right Dave, it is nothing more than money making.  

I think (to a degree) Part P is pretty good as I've seen some shockers done by home owners, but have also seen worse done by so called qualified sparks.

[Davey-T]

Ah the tales we could tell Ray, from the guy who had "rewired " his kitchen with orange cable off his old B&D lawnmower to the old lady who paid a sparks to rewire her very old house and he chased new cable 6" up the walls, joined onto the old cables and then taped the joins with sellotape.

When we investigated she had every sort of cable going back to the invention of electricity strewn around the house, most of it with no earths, we ended up rewiring the whole place for the cost of the materials out of sympathy.

After some gas fitting we could smell gas and the " fitter " said it didn't matter as it passed a drop test so couldn't be much.

Dave

 

[RayD]

1 minute ago, Davey-T said:

Ah the tales we could tell Ray, from the guy who had "rewired " his kitchen with orange cable off his old B&D lawnmower to the old lady who paid a sparks to rewire her very old house and he chased new cable 6" up the walls, joined onto the old cables and then taped the joins with sellotape.

When we investigated she had every sort of cable going back to the invention of electricity strewn around the house, most of it with no earths, we ended up rewiring the whole place for the cost of the materials out of sympathy.

After some gas fitting we could smell gas and the " fitter " said it didn't matter as it passed a drop test so couldn't be much.

Dave

 

No way!!!! That's outrageous.  I've not seen anything quite that bad I have to admit so you've well and truly top trumped me there!!

 

[SonnyE]

4 hours ago, AlistairW said:

Hello,

In a quest to always minimise set up time I have a pier in the middle of my small garden with a 10m distance to an outdoors 240V supply. Currently I simply run a 10m bog standard extension lead from the pier to the junction box, which I unroll and roll up every session.

What if I were to buy a 10m of 3 core armoured cable, put a plug on one end and a socket on the other - essentially just the current extender with but made with an armoured cable - then, burry the cable under the lawn. This would create a permanent supply to the scope.

Couple of points, the junction box (I think) is connected to a RCD via the fuse box in the house (the house was only built 2 years ago). Also I think that cable should be buried to 0.6m depth, however I am not intending on wanting to go much below a spades depth, as only a rotary lawn mower would skim across the surface, and I would know where the cable is anyway.

Does this at all sound safe or a recipe for electrocution ?

Thanks

Alistair

 

Mostly, this all depends on your local electrical codes, and what is allowed.

Here, we can use UF (underground feeder) cable which is designed for direct burial, and is also sunlight resistant. Typically though it is run in rigid conduit to help protect it where it surfaces. And usually 2 feet down. Outdoor circuits here are typically fed with GFCI circuits, Or Ground Fault Circuit Interrupters.

Me, I just have an extension cord from a GFCI outlet, and it feeds my laptop's power supply. When my 12 volt battery gets low, I plug in my charger and set it to recharge my big battery. I'm not so hot on doing permanent type electrical work where my temporary works just fine. I have what I need and it's easy to pack it up should I want to travel.

If I was to put up an observatory building (not likely), then I would probably put in a permanent circuit. But I'm doing fine with what I have, and WiFi from my laptop to my desk computer for imaging.

[michael8554]

Hi Alistair

How about a compromise - get a quote from a qualified electrician, but specify you want to do the grunt-work yourself?

You dig the trench, line it with shingle or whatever he specs.

He replaces your external socket with a waterproof junction box, attaches the armoured cable with a waterproof gland, lays the cable, attaches other end to a suitable socket outlet.

You fill in the trench with hazard tape and shingle etc to his spec.

 He tests the installation.

Michael

[RayD]

5 hours ago, michael8554 said:

Hi Alistair

How about a compromise - get a quote from a qualified electrician, but specify you want to do the grunt-work yourself?

You dig the trench, line it with shingle or whatever he specs.

He replaces your external socket with a waterproof junction box, attaches the armoured cable with a waterproof gland, lays the cable, attaches other end to a suitable socket outlet.

You fill in the trench with hazard tape and shingle etc to his spec.

 He tests the installation.

Michael

Great idea.  Provided the outside socket is part of a ring and not already a spur of course, or is on it's own radial, then he could keep it and just add the additional socket so he doesn't lose the one he already has. 

The biggest costs is labour, so doing the digging etc. will definitely cut the costs loads.

Hope you get it sorted 

[Davey-T]

Just a thought, does it all need burying, can some of it be clipped to a fence / wall to save some digging ?

May not be possible in your case but my obs'y armoured runs along the fence to the bottom of the garden.

Dave

[Ouroboros]

35 minutes ago, Davey-T said:

Just a thought, does it all need burying, can some of it be clipped to a fence / wall to save some digging ?

May not be possible in your case but my obs'y armoured runs along the fence to the bottom of the garden.

Dave

I do something similar with cable along the fence, but it's not a permanent arrangement and the cable isn't armoured.  Both ends are inside and dry. I use a hard wired RCD plug on the input end. I tend to do astronomy in sessions around the new moon as opportunity arises. Between times the cable is packed away. I had thought of using armoured cable fixed to the fence like you. Strictly speaking what you are doing is not a permenant arrangement. As long as it's only you using it, and it is unpowered when not in use,  I can't see it as a problem.  I guess if you move house you should dismantle it.  I should add this is not a recommendation to do this. It's always best to employ a suitably qualified professional to install electrics. 

[Ouroboros]

Has anyone experience of hiring a mechanical trencher?  I know you can hire trenchers about the size of a petrol lawn mower which cut a trench 100 mm wide or so and 750 mm deep. I'm wondering how expensive hiring one is and how easy they are to use. Unfortunately I know my ground is incredibly rocky under the grass and I suspect only a small digger would handle it.  Plus there's a 2-3m wide curtain of concrete near the house I'd need to get through with a pneumatic drill.  

[Putaendo Patrick]

How are you going to protect an exposed socket in the middle of the garden?

[Davey-T]

6 minutes ago, Putaendo Patrick said:

How are you going to protect an exposed socket in the middle of the garden?

http://www.qvsdirect.com/13a-1-gang-impact-resistant-ip66-outdoor-weatherproof-switched-socket

Dave

[Putaendo Patrick]

Thanks, Dave!

I was really thinking you're going to need some sort of post to support the weatherproof socket, and this may cause more of a hazard for tripping over than the cable for electrocution! And if it's in the middle of the lawn, will it complicate cutting the grass? Running the existing extension cable almost seems the simpler option .