external power query

[search]

hiya folks

firstly an excellent site and good to see so many people offering guidance and expertise.

i have a garage consumer unit which has 2 mcbs, one for lighting and one for a small ring with 3 doubles scatterred around the garage, about 10 metres away from the garage i have built a big shed to house some parrots i keep and i'm now wanting to install 10 video camera's to their cages, they run of 12 volt power supplys so there is no real power consumption. as my cu in the garage is being used how do i get a power supply up there.

is it possible for me to replace the cu in the garage with a bigger one, and from here use a 30A mcb and run it to my shed and install the old garage cu in the shed, and then run a small ring in my shed for the camera's. so in effect from my main consumer unit i have a cu running into the garage and from there have one running in the shed, for some reason it doesnt seem right, can anyone help shed some light on this please, i would not be running anything else up in the shed.

many thanks in advance

 

[Dellsmp]

Outside power is now covered by part p of building regs and therefore I'd recommend that you just plug in an extension lead in the garage, which presumably has an rcd? anything else will require a registered spark or notifying the labc.

 

[jondiy]

Why not keep your mains appliances in your garage, eg camera monitor/vcr and camera power supplies, etc, and run 12 volt feeds from the garage out to the shed, and run the video camera signal wires back to the garage from the shed.

As the 12 volt feeds are isolated, then you have no major safety issues as it is SELV. Just make sure the cables you use to run the 12 volt supplies are rated high enough for the current you are drawing through them. Also make sure the 12v supply transformers are fused suitably, and keep them in a dry location where they can keep cool.

Use large conduit to keep the cables dry where they travel outside , i can't see how this method would contravene any regulations, however there is probably somebody out there who will beg to differ! (BAN), so again, just partial advice/ideas for the person posing the question.

The only problem I can forsee is with lack of lighting in the shed, the cameras wont pick up any vision (unless you get ir/nightvision cameras), but hey, are you going to stay up all night watching your parrots??? No

 

[search]

hiya guys

thanks for your advice, yes your advice makes a lot of sense, the camera's are presently in the garage and they are connected to my pc in the study, yes they have infa red so watching in the dark is no problem. so what i gather is i run an extension lead up to the shed and then run a couple of extensions to enable me firstly to reach all the camera's and secondly each camera has its own power supply, is it safe as i would need a t least 10 sockets, or are you saying i need to coonect all ten from the garage and then run their leeds right up to the shed and directly into the camera's.

many thanks

 

[Steve]

I take it all the cameras have the same power supply? Add up all the camera's current ratings (in mA) and buy a single transformer rated appropriately, run a single cable to the shed and split it there for each camera.

Or use a proper camera power supply with multiple outputs, and run, say, 4-5 cables out to the shed.

All these ELV cables in plastic conduit where outside, of course.

I work in a 1000ft² shop which has 9 security cameras. why do you need 10?

this would be an ideal power supply, provided your cameras are compatible of course!!!

 

[plugwash]

Or use a proper camera power supply with multiple outputs

from the photo in that pdf it looks like "proper camera power supply with multiple outputs" means "normal single output power supplly plus a few polyswitches in case of short circuits"

 

[ebee]

Still comes under Part P though

 

[Qedelec]

Yup and notifiable too!!

 

[jondiy]

3. Work on -

(a) telephone wiring or extra-low voltage wiring for the
purposes of communications, information technology,
signalling, control and similar purposes, where the
wiring is not in a special location;

Does not need notification.

How can you justify Part P ??? All the cables will be either 12 volts or video signals , all placed in plastic conduit. The existing house wiring does not need to be touched as the psu's are most probably on plug tops, and considering they are being left in the garage, I can't see what contravenes the regs or part p.

Bascally the guy wants to fit LOW VOLTAGE external cameras, to his shed, to be viewed from the house !!. Where is the harm in that?

 

[Steve]

3. Work on -

(a) telephone wiring or extra-low voltage wiring for the
purposes of communications, information technology,
signalling, control and similar purposes, where the
wiring is not in a special location;

This is ELV for the purposes of POWER supply for the cameras. And it will be FIXED WIRING in the conduit.

 

[search]

thanks for all the info guys, i'm gonna take all the low voltage wires through conduit to my shed, so i take it i'm within the law judging from the above post, can someone give me the nod.

many thanks

search

 

[jondiy]

Yes, crafty, were you agreeing with my quote that it should'nt need notification , or do you think it IS notifiable?

 

[Steve]

jondiy, I was disputing your post. You quoted that work on ELV installs for the purposes of communication and signalling applications was not notifiable. (The above implies the actual signal cables which transmit phone/data/tv signals, NOT to supply power to anything)

However, this is different because he needs ELV for the purposes of POWERING his signalling equipment (cameras)! Which, AFAICT, and stupidly, is notifiable. And is the garden not a special location? And this will also be fixed somehow, conduit was mentioned.

 

[jondiy]

Ok, I'll go along with that. Although I would term fixed wiring as wiring that is PHYSICALLY connected to the main supply, ie at all times regardless of whether in use or not, eg a circuit. Just because conduit is used, it does not make it FIXED, I mean you could run some speaker wires down it out to a garden speaker, and then would you call it FIXED??

I'll go along with the power side of it, although it does seem silly, I mean , as the 12 volts is islolated (and the transformer supply fused) , and there is no earth present on the transformer output (hence no potentials introduced) , then where is the shock risk, other than direct contact between the two terminals (which will be low voltage anyway!!!)

To this end, it would obviously deem most garden lighting projects unsafe (or notifiable) , as it is the exact same principle - power goes to garden lights, as it would the cameras. Yet I don't see any warnings down the local diy store telling me that garden lighting is notifiable!!!


BAFFLED!!!!

 

[Steve]

it is very confusing. maybe ban will be along in a minute to clear it up!

I mean, if i fit an outside light screwed to the wall outside and run flex through a window frame to a plug top in the kitchen, is this notifiable? Where does it stop?

And did anyone ever clear up what context "fixed wiring" should be used - fixed as in "electrically connected permenantly", or fixed as in "stuck to a wall"

DIY stores dont want to advertise part p too much - they would loose a lot of trade from DIYers.