external data cable

I would like to link our house and garage using cat5/6 data cable allowing internet to be shared. The route i would like to take requires digging a trench and the total cable distance comes to about

70m inluding going around walls etc. External grade armoured cable seems to be obscenely expensive so would some kind of outdoor grade cable within a conduit be acceptable?

also the garage and house are on completely different electricity mains supplies with different meters etc. Is this a problem in terms of linking them because they have seperate grounds?

thank you for your help Pete

Reply to
pj
Loading thread data ...

Have you considered using Homeplug units? They work very well for me over a distance of about 30 metres between a house and a barn, although they do share the same meter. Using Homeplug would remove any worries over earthing and lightning strikes.

Reply to
Simon

I would lay a duct, and then for starters just pull standard cat5/6 cable through it. If it dies quickly, then consider something more expensive.

Only if you are passing signals between the buildings which carry a ground. Twisted pair ethernet is completely isolated at both ends, so that's OK. Phone cables carry a ground, but it should never be exposed by the phone instruments.

Reply to
Andrew Gabriel

We'll have w_tom along in a minute!

Reply to
Bob Eager

Wouldn't wireless be a lot easier and cheaper?

An access point at each end with a couple of directional aerials. The whole lot should come to about =A3120 and would take an hour to install.

Reply to
stevelup

As in if lightning strikes the mains they blow up the same as any other kit there at the time?

Reply to
dennis

You should not use copper for data links between buildings. If you've got separate electrical supplies you may have enough potential difference between ends to exceed the common-mode rejection of the ethernet receivers and cause data problems. And in the event of nearby lightning discharges you may get enough energy picked up in the cable to damage the equipment at each end (fried chips, ha ha: I've seen one whose black epoxy package was reduced to white ash by a cloud-to-cloud lightning discharge overhead).

Depending on the value of the your kit at each end you might suck it and see, but the pukka way to go is either fibre (you can get pre-terminated lengths made up to your specified length, which you can pull through a suitably-sized duct) or - as others have suggested - wireless. Powerline probably won't work if house and garage are on separate supplies.

Reply to
John Stumbles

On Sun, 18 May 2008 04:53:25 -0700 (PDT) someone who may be pj wrote this:-

A distance of say 40m in a straight line between buildings is not good for connecting by copper data cables, for the reasons others have given. There are precautions which can be taken, but these add to the cost.

If against this advice you really want to do it then I suggest . This could be buried in the ground, at a suitable depth, with protection against rodents where it emerges from the ground.

Reply to
David Hansen

Wonder how broadcasting got round this in the old days - all lines between building were copper. And indeed around the country. Of course most of these lines were fed via a balancing transformer which would provide low voltage isolation - but certainly not from high voltage or lightening. And I'd guess later equipment used electronic balancing.

Reply to
Dave Plowman (News)

On Sun, 18 May 2008 13:07:57 +0100,it is alleged that "Simon" spake thusly in uk.d-i-y:

[snip]

Would homeplug units not have a problem with the garage and house being on different supplies? Or are they radio units?

Reply to
Chip

And [twisted pair] ethernet works exactly the same way -- there's an isolating transformer at both ends of the cable (rated to 4kV each IIRC).

It won't survive a direct or very close-by hit. The cost of equipment which does would be considerably more than the cost of replacing some ethernet cards and routers.

Reply to
Andrew Gabriel

If they are different phases or the interconnect point between the same single phase to each building is at a distance then I suspect homeplug type stuff will struggle or not work.

Radio as in they inject a carrier onto the mains wiring but not radio as in wireless. B-)

Reply to
Dave Liquorice

That's what I guessed - in the same way as a router or modem is isolated from the BT line.

Indeed.

Reply to
Dave Plowman (News)

thank you all for your prompt replies! in answer to a couple of you the electric circuits are completely seperate making homeplug inoperable. I would like if possible to keep a physical data link as ive had bad experiences with wireless reliability, plus using cat5 i can go up to gigabit if needs be.

As with the comments above everyone seems to have conflicting views on whether its a good idea to link buildings. Im not interested in using fibre as its WAY too expensive for this project. A cheapo =A320 switch will be at either end of the line so im not too bothered if the risk of it blowing is there, as long as it isnt a common occurance!

I'm torn as i would like to try it but dont want to do anything dangerous in any way. The building is being done up and will have an office in the end of it that requires internet access as well as reasonable transfer speed for backup purposes.

thank you for your comments Pete

Reply to
pj

Have you looked at including one (or two) of these?

They would need to be installed with a serious earth spike each to be any use, but that's basically only a metal rod into the ground. That would make it absolutely safe.

When I did the same thing (from a stable block office to a farmhouse) I just ran outdoor spec Cat-5 in a buried PVC pipe then had a cheap switch each end, away from anything flammable... sound familiar?

Reply to
PCPaul

would plugging each end into a surge protector with an ethernet port have a similar effect? or a UPS? also both buildings run off the same transformer and are about 10m away from each other - surely it shouldnt be this hard to link them

Reply to
pj

In the real Old Days (TM) they used valves, so no problem.

I gather that when the USAnians started trying to make their military electronics EMP-proof so that they could chuck nukes around and still keep flying etc, they found that the Soviets were way ahead of them: the MiGs etc used miniature valves in their avionics!

Reply to
John Stumbles

Really? I thought 10 and 100BASE-T used basically RS422 Tx/Rx and 1000BASE upward more or less followed suit with more fancy signalling. Squeezing the higher rates through transformers whilst still being backward-compatible with the lower rates is a feat that boggles my little mind!

Reply to
John Stumbles

True - but transistors were around for a long time while the majority of landlines etc were still copper twisted pairs. Indeed, most of our houses are still connected to the local telephone exchange in this way.

I can remember Russia selling valve equipment for the domestic market long after solid state had become the norm - and at the bottom end of it too. Guess they had factories they just had to keep employed. ;-)

Reply to
Dave Plowman (News)

Nope, there is an isolating pulse transformer at each end of each signal and and isolating DC-DC convertor in the PSU for each Ethernet TP interface (if it is done correctly). The transformer usually looks like a DIL pack but a bit higher than normal.

There are a few variants of 100M too some which use two pairs and some that use four pairs, don't mix them as they wont work. The four pair variant (100base4) was supposed to be for older cat 3 cable runs AIUI but IME people just plug it in and if it doesn't work they run a new cat5 anyway.

1000M uses the four pairs IIRC.
Reply to
dennis

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.