ECN Forum Forums General Topics of the Trade General Discussion Area telephone

Is it currently standard practice for lightning arresters to be fitted on tel. lines where they enter premises?

This isn't done here, but then we don't get anything like the number or severity of storms that many parts of the U.S. get.

I see a lot of older telephone entrance that has a lightning arrester, usually it is two 3 or 4" cylinders about 1/2" in dia.
I don't see this on newer installations.

The old ones had the gas discharge tubes you described. The new ones have something different. But they still must be bonded to the AC system's GEC.

Do they perhaps use MOVs (Metal Oxide Varistor) as the modern equivalent? These seem to be the current method for surge protection in power strips and tel. line protectors for computer equipment.

> Do they perhaps use MOVs
I haven't opened up the telco side to check. I'll have to look.

My guess would be a cheap choke that shunts the magnetic field to ground.

MOVs would have to be checked after every event and replaced if damaged. MOVs are relatively expensive compared to iron chokes.

I have seen nothing to insinuate this protection on the premisis, perhaps it would be on the pole??

>I have seen nothing to insinuate this protection on the premises
Seriously? All telephone network interface boxes have a solid copper wire attach to the GES or similar and tagged with a statement to the effect that the wire must not be disconnected or else the house will burn down and if you see one disconnected, call the telco.