Phone Line Grounding

[hillbilly]

Hey Guys

I need to ground a telephone line that runs to a motor driven, driveway gate.
The gate operates on 12 VDC battery power, but it has a 120V (dedicated circuit) receptacle that powers a trickle charger.
The receptacle circuit is #12 UF fed from a (well house) breaker panel that's about 100' away.

The phone line is presently not grounded to anything (#10 phone company cable grounding conductor), and I think Lightning damage is the reason the "$500 mother board" in the gate has been replaced 3 times in 12 months......

I've thought about driving a ground rod at the gate and bonding it, the 120V circuit grounding conductor, the gate enclosure, and the telephone cable grounding conductor together.
This would give the system a outlet for any voltage spikes that may be induced in the phone line.

I'm not sure about bonding to the #12 equipment ground (120V circuit).
Does that sound reasonable? Any problems?

Thanks in advance for any reply.
steve

 

[zbang]

Is this a -telephone- line or a control line for the gate? Phone lines are never grounded, but rather run through protector assemblies which conned to a local ground (there should be one at each end).

 

[barbeer]

I might look at surge arresters as well.

 

[hillbilly]

Is this a -telephone- line or a control line for the gate? Phone lines are never grounded, but rather run through protector assemblies which conned to a local ground (there should be one at each end).

Yes, it's a telephone line that's dedicated to the gate operator.
It allows the owner to open the gate via a telephone call to the gate operator.
The gate sits by itself at the entrance to this "estate", and is approx. 1/4 mile from the residence.

This is the regulation direct buried phone cable that I'm talking about.
It's about 3/8" diameter, shielded and has a bare grounding conductor enclosed inside the sheath.
Normally, this cable grounding conductor is bonded to the GEC at the demarc point outside a residence.
Since there is only the 120V AC circuit at the gate, I plan on bonding to the circuit EGC, and a ground rod that I've driven.

Lightning strikes have really been a problem concerning this gate, and I'm looking for a way to give the induced voltage spike a outlet to earth, other than through the gate operator.

My main concern is bonding to this #12 EGC.
I don't know if the resistence of this 100' long wire will prevent it from helping much, and also don't want to magnify any problems.
I've never seen this done before, so I came to the experts for advice.

thanks
steve

 

[dereckbc]

Steve I do a lot of data centers and telephone office design build and all these facilities use a similar gate control circuits.

You need to do 2 things, will really 4.

At the gate, and building where the circuits leave you need to install TVSS and a line protector on the phone line. At the gate install a ground electrode like a rod or two. Bond the sheath of the phone cable, the EGC of the 120, and the protector/TVSS to the ground system. Do the same at the building where the circuits exit the building.