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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> piggybacking into thick black cable... https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1340151793 Message started by sparkynoob on Jun 20^th, 2012, 1:23am

Title: piggybacking into thick black cable...
Post by sparkynoob on Jun 20^th, 2012, 1:23am

hi there i need to run a new power cable up to my garage, i already have what looks to be like black tubed 3 core around 150-200mm thick. can i run a new cable off of it by piggybacking onto this? it will be running just the lights. could you please advise how i go about making a safe connection from the current cable to a garage e.g terminal box piggyback disconects etc.

Title: Re: piggybacking into thick black cable...
Post by Lectrician on Jun 20^th, 2012, 6:57am

Much more info needed.

150-200mm?? Are you sure ::)

Can you take some photos?

What is the cable currently feeding? What is it's protection at the origin?

Title: Re: piggybacking into thick black cable...
Post by CWatters on Jun 20^th, 2012, 8:22am

Any writing on the existing cable? Can be hard to see sometimes.

Title: Re: piggybacking into thick black cable...
Post by sparkynoob on Jun 20^th, 2012, 8:42am

i can take some photo's after work of course :) its feeding a water storage container, has a light grey/ cream coloured rectangle box on top of the container which the thick cable goes into, i will get more info when i take pic's later. hopefully the voltage etc will be on the box.

the water container is a big 50 Gal by the way.

Title: Re: piggybacking into thick black cable...
Post by Lectrician on Jun 20^th, 2012, 11:31am

The water container may simply have a float switch in it, no pump etc.

If so, the cable will more than likely only have a live and switched live, and possibly only 24V AC. A photo of the connections either end would help.

I doubt this cable can be used to supply anything additional, but we will see!

Title: Re: piggybacking into thick black cable...
Post by sparkynoob on Jun 20^th, 2012, 4:37pm

no photo yet but the container is a Titan V5000, 1100 Gallon/5000 litres

its spec is here:

http://www.tankdepot.co.uk/shop/458_102/heating_oil_tanks/titan_single_skin_heating_oil_tanks/titan_v5000tt_single_skin_heating_oil_tank.htm?

found out its infact an oil tanker, i only bought the site a week ago so my apologises for thinking it was water storage but then it looks like one i guess. anyway hope the spec helps.

im also not 100% sure but i think the power the other end is ran by the gas generator which we keep on standby all the time.

Title: Re: piggybacking into thick black cable...
Post by sparkynoob on Jun 21^st, 2012, 11:04am

anyone?

Title: Re: piggybacking into thick black cable...
Post by Lectrician on Jun 21^st, 2012, 6:21pm

Not alot we can tell you :P

It's a big plastic tank!

No idea what cabling would be required for it - none really! Is it being used for water or oil? Is there a pump or float switch?

Are you sure this "cable" is not a pipe?

Photos required - we can't help much further without.

Title: Re: piggybacking into thick black cable...
Post by CWatters on Jun 23^rd, 2012, 11:40am

Sparkynoob,

The answer to the question is possibly. But more info is needed before anyone can tell you for sure.

What it's connected to at the source end?
Exact diameter of the copper cores so the cross sectional area can calculated (or it might be marked on the cable outer?).
Length of cable?
Required load at the garage end? Just a few lights? No sockets at all?
Is the cable armoured?
Is the cable burried in the ground?

Can the cable be disconnected from the oil/water tank? If not then you're going to have to find out more about what the wire is doing and if you still need it to be doing that. If the wire is sending data about the water/oil level somewhere then it might not be possible to use spare cores (if any) for mains. If it's supplying power to a pump in/at the tank then you need to know more about the pump.

Best get someone local to look at it.

Title: Re: piggybacking into thick black cable...
Post by sparkynoob on Jun 25^th, 2012, 8:42pm

i took the top off the box which is located on top of the storage container. it shows the inside cables and the box it's self.

outside of the box :
[gallery fullsize]sparkynoob/1340692617.jpg[/gallery]
Larger: http://img833.imageshack.us/img833/2960/img0985t.jpg

inside:
[gallery fullsize]sparkynoob/1340692627.jpg[/gallery]
Larger: http://img861.imageshack.us/img861/6135/img09892.jpg

i presume its connected to a pump as the box is right above a large plastic pipe that carries water/oil.

you can see the size of the cores in the pic, the outer shell is 15mm thick. black on the outside rubber, then white inner rubber, then the three cables you see.

the length of the cable is around 150- 200 metres long. so its going to be much easier to run more cable from here to the garage rather than back from the meter.

glad you reminded me about sockets. im wanting to connect up some CFL lights in ballasts, 2-5 sockets & some more 45 watt lights for my wifes indoor growing area.

be grateful if the pictures in more info given helps as im getting ear ache about it now lol.

Title: Re: piggybacking into thick black cable...
Post by Lectrician on Jun 25^th, 2012, 9:31pm

Looks like a 1.5mm² or a 2.5mm² cable. Still can't tell if this is for a float switch or something else such as a pump. You would need to confirm that, but in any case, in my opinion this cable is not suitable.

Title: Re: piggybacking into thick black cable...
Post by sparkynoob on Jun 25^th, 2012, 10:15pm

thanks for the quick reply, whats the max that would be useful if i ran power from this ? ive found the cable used online and it says max 6Amps. is it not even to give enough juice for sockets?

Title: Re: piggybacking into thick black cable...
Post by Lectrician on Jun 26^th, 2012, 7:33am

At 150m long, no way at all, even lights would be a possible issue.

You also need to understand that if this is for a float switch there will be no neutral, just two lives.

There is no way this cable can be utilised for sockets or lights.

Title: Re: piggybacking into thick black cable...
Post by CWatters on Jun 26^th, 2012, 7:59am

If the data sheet says 6A max that sounds like the conductors are 1.5mm².

However if you put 6A down 200m of 1.5mm² the voltage drop will be way too high. The online calculator I played with suggested the maximium allowed was going to be around 1-1.5A (less whatever the "pump" is taking). Too low for what you want.