I was wandering if any one els provideds some kind of Lightining/High Voltage protection when instaling there comms. I ask this because I do. Any thing that is connected to an outside network is vonrable. I remeber not so long ago January I think when we had a electrical storm with heavey snow. I was called out to a NHS radio mast that was not responding to telementry turned out that one of the radials had a direct strike knockig out both the main and back up links. After being on site I started to get phone call after phone call informing me that there was other problems in the same area. Any way long storey short this bolt of lightning traveled for 3.2 miles and radited out a good mile and a half in the proces blowing everything that was connecteted to the public network. The morel of the storey is eiven with lightnig aresters built in it seemed to blow 4 sets on the way and still did the damage. The poor bloke that was on the same farm who had a small computer business had his Distribution Board blown apart and indented in a wall Just at the same hight as your head well you can guess he almost whent bust because the insurance companey were trying to get out of paying for his computers, Alarm well anything that was pluged in. Any way I spent a week with a brother working in 6ft snow drifts erecting new cable and remaking joints blodey amazing that know one was killed. This had to be the worst strike I had seen for 5 years the normal is normely indirect strikes producing high voltages and blowng phones and modems.

I have a surge protector and UPS on my main PC at home, unfortuntely the laptop and other PC's aint protected, but I do pay around £220 extra a year on insurance just for IT equiptrment cover!

If there is an earth terminal on a digi/redcare/dialler I always use it. If it still gets blown up it aint my fault!

Yep we do. NSI insist that if there is aterminal for a an earth connection it gets used. But during a lightning storm if any remote signalling goes down it tends to be the ones with an earth connection.

True it isnt your fault but what if you had spent 4 days installing a big system you protected the Mains with a surge surpresser and didnt do any thing to your coms it will just flash over going in to every way it can burning out all your cables sensors and any thing els. Well its back to square 1. I surpose if your a big national then it will not matter much because you will be able to cover the cost time on site and the such. But if you you are a one man band then ure stuffed. OK it might be over engineering but hay when you see what damage can be done it makes you think. The Most vunrable are those being fed over head and people on hills fed O/H U/G.

OK you cant protect from a direct Cloud to Ground or Ground to cloud (Yes Lightining can go up i aint mad ) but to protect from Induction from close or direct that was some KM away it could save a lot of time and hastle.

Edited July 28, 200421 yr by smart1

Yep we do. NSI insist that if there is aterminal for a an earth connection it gets used. But during a lightning storm if any remote signalling goes down it tends to be the ones with an earth connection.

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I didnt know that

NSI insist that if there is aterminal for a an earth connection it gets used

So do the SSAIB, must be min of 1mm dia cable..(thats what they said anyway)

NSI insist that if there is aterminal for a an earth connection it gets used

So do the SSAIB, must be min of 1mm dia cable..(thats what they said anyway)

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Actually, I'm led to believe the earth cable from the redcare/digi etc must be the same diameter as the mains supply feed in, ie if the mains earth to the panel is a 1mm csa then so must the earth link to the comms equipment...

I think thats iee 16th?

but it makes sense...

James

memorys not that good now due to age, but I am pretty sure there were roumours around a few years back, that it did not make a difference weather earth link was conected on comms or not, because whenever there was an electrical storm comms would get fried irrespective of the fact that the earth tag was conected or not.

Also me thinks some manufacturers did away with the earth terminal, dunno may be stood to be corrected.

Edited July 29, 200421 yr by orinoco

i think the womble is right - scantronics digi don,t (i believe) have an earth connection

paul