Home>Discussions>ELECTRICAL & LIGHTING>cable , telephone , internet voltage in line from cable co.
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dave coppage
cable , telephone , internet voltage in line from cable co.

Over the past few months we've had numerous visits (repair calls)from our local cable tv company (tru vista) .... to try and correct and repair numerous outages . First they told us we had no low end signal on our cable but would install a new line .
The next thing we knew , computers , telephones , modems , copiers , faxs , alarm systems were shorting out , we were told that it was a lightening strike ( ok ,, maybe ) went to store replaced items , within a day they blew again ... (NO STORM ) then told power surge ( doubted but maybe ) still they never checked the line . Next guess what blew more things , here they come again , their line block on the house was melted and the cable fried , when they put the cable up near the block .... it shot sparks .... or arc'd . that was when they started looking at the cable ... said it had current coming through it , but , heres the query , how ... being cable line has NO current going through it . The company has tried to blame the Electric co. ( overhead lines ) low voltage irrigation lines 200' away , ground fault outlets on a building 50' away ( electrician has checked all outlets and current NO LOSS ) ,
I'm out over $10,000 worth of electronics blown by the cable ...


all help will be appreciated
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Re: cable , telephone , internet voltage in line from cable co.

I'd look first at your house wiring, particularly the ground. The cable has a ground on it, probably back at the source or maybe at the power transformer's "phone ground". Your house ground could be at a different ground potential. When there is a difference of potential, current will flow.

The power lines coming into your house consist of three lines, two have 120 volts that are 180 degrees out of phase so they measure 240 volts between them, and a neutral aka return line. The neutral line should be grounded to the tank wall on the outside of the transformer. In your breaker box, this neutral wire should also be grounded to your house ground. The transformer is also grounded to a line leading back to the substation. This keeps all grounds at the same potential.

The phone companies and cable companies are allowed to use this ground as well. If they aren't, or one of the ground links in your houses wiring system is disconnected, one side or the other could have a "floating ground".

A lightning strike could cause one of these links to disconnect, but its unlikely. If the power lines had a broken ground or return line, you neighbors would be experiencing the same problems. Same is true if the cable company had a ground fault.

Corrosion is a likely culprit when it comes to ground fault problems. You should get a licensed electrician to look at your house wiring and check for grounds or ground faults.

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