Lightning protection and residential landscape lighting

You really need to get a good grounding system for the whole house W.Tom may be along to talk about that more but it is the first line of defense. I suspect your "rocky hill" prevented them from really driving any effective rods. I would look at things like ground rings and other buried electrodes. Then you need to be sure all of yoiur protectors get bonded to that electrode system. Do not have separate electrodes that are not all bonded together. That is creating a path to disaster through your equipment. I am betting your well casing was not bonded to the ground electrode system with a fat wire. (6ga or larger)

please descibe the lightning protection system.

i would not worry too much about this (assuming burried cables).

probably not, but in the case of a direct lightning hit its difficult to predict results.

in the case of off the shelf low voltage lighting transformers, i doubt it.

one common ground point. there is nothing preventing you from installing six or eight ground rods and/or running a copper cable to the well casing.

If I ground the transformer to

your well casing is probably the best ground point that you have available to you. assuming a submersible pump my guess would be that lightning (or surges) like to traverse the power line to the pump.

on a current project an electrician quoted me $6,000 to install 6 ground rods bonded together plus 4" copper strap to the equipment. i declined his bid. another electrician recommended bonding to and existing tower ground. i was able to get 50' of 1" copper tubing at a hardware store for less then $200. the copper is brazed with copper-phosphorous for a solid electrical and mechanical connection.

Hi,

Thanks for all your help. The lightning system was installed by Associated Lightning Rods

and cost was $US 7,340. It has 6 grounds and 11 air terminals. They protected the well head with something and messed about with the main's box too.

I think they used long grounding rods for grounding. How good these ggrounds are I do not know. I hope they tested them ..... do professionals usually test the grounds ....?

Best, Mike.

TimPerry wrote:

Those lightning rods give lightning a path into earth that does not use structures or trees. Now lightning is in earth - and still seeking earth borne charges maybe a mile distant. If a shorter electrical path is into those underground wires, through low voltage transformer, through house, and out via AC electric earthing electrode, then you still have a potential problem.

Simple rule is that all wires entering a structure enter at one point. Every wire in every cable then connects to a single point earth ground

- either by direct (hardwire) connection or via a protector. IOW that low voltage wire should enter where AC electric, phone, and cable also enter building AND may require a protector that makes the short connection from each low voltage wire to earthing electrode.

If that is not possible, then other solutions include halo ground or solution demonstrated by a utility:

Lightning (airborne or earthed) that need not travel through a building to distant charges should not cause household electrical damage. But again, that means any wire that enters the building must do so at a common point (or common point expanded to accomplish same) so that each wire is earthed to a common earthing electrode.

Lightn> My house is on a hill which is rocky. After getting hit at least twice

Those lightning rods give lightning a path into earth that does not use structures or trees. Now lightning is in earth - and still seeking earth borne charges maybe a mile distant. If a shorter electrical path is into those underground wires, through low voltage transformer, through house, and out via AC electric earthing electrode, then you still have a potential problem.

Simple rule is that all wires entering a structure enter at one point. Every wire in every cable then connects to a single point earth ground

- either by direct (hardwire) connection or via a protector. IOW that low voltage wire should enter where AC electric, phone, and cable also enter building AND may require a protector that makes the short connection from each low voltage wire to earthing electrode.

If that is not possible, then other solutions include halo ground or solution demonstrated by a utility:

Lightning (airborne or earthed) that need not travel through a building to distant charges should not cause household electrical damage. But again, that means any wire that enters the building must do so at a common point (or common point expanded to accomplish same) so that each wire is earthed to a common earthing electrode.

Lightn> My house is on a hill which is rocky. After getting hit at least twice

they should on critical instillations, unusual circumstances, and when the customer demands it.

i bet you have a great view :)

i have similar problems with lightning knocking out tower light flashers. i combat it by creating inductors from a few turns of wire. it's not a guarantee but it does seem to cut down on maintenance. before the addition i was replacing fuses and/or flashers every few storms. the inductors are positioned in the controller box nearest to the flasher unit.

A metal well casing is just about a good of a gound as can be gotten. However recent practice is to use plastic pipe for both the casing and the water pipe.

It's routine to put a surge suppressor on or near the "control box" for the well. As discussed in this group a month or so ago, smaller pumps (1 HP range) don't have a control box but incorporate the starting elements in the pump. These pumps have a built in surge suppressor.

>

The well is still an excellent path to ground so if you are not doing something to shunt that fault you have set up a problem. I certainly would not cheap out on the EGC to the pump and be sure your surge protector attaches to that conductor. A 6ga GEC "jumper" and a rod might be a good idea.

Well, if you have metal pipe, a metal tank, etc, then just running the ground wire through the pressure switch will definitely ensure that any surge arrestor nearby will definitely have a good shot at bypassing that surge to ground.

If you don't have to make too many extra holes in your wall then running some #6 from your water tank to the ground at your service entrance would definitely be a good idea.

When I first moved out to "the country" one of my early "projects" was to put a TV antenna as high on the roof as I could manage. At the time I was able to pick up a spool of #6 Cu wire for about $40. I bonded the antenna structure to the "official" ground, to a few ground rods I installed myself, and to an Aluminum bar that was sticking out of the ground. When I finally got a generator, I pounded an 8' rod and set up a "pigtail" to connect the generator, the new rod and the existing system together. I've gotten a LOT of mileage from that spool of wire.

But this was all "outside." To run the #6 from the pipe to the ground wire would require making a hole in the outside wall. It's definitely bonded already but only via the water pipe and the ground wires for the pump and the water heater. I guess it's 2 #10 wires.

What's funny is that the house is covered with metal (steel!) siding. The siding is "floating." The boxes for the outside lights have incidentally grounded some of it but it's covered with an insulating coating so most of it "floats."

---------------------------- Low voltage installations are ungrounded (at least mine is) so it is floating. With ground currents from lightning, there will be negligable differential voltage due to these currents, across the transformer secondary. That will not be a source of transformer failure or a transmitted surge into the house. Any problem would be with any potential which occurs between the neutral of the transformer and the local ground potential. That would also be present at any outlet which may be used to supply the transformer. As for the well controller- is there any surge protection and how far is the pump from the controller? There may be a tolerable surge which is reflected from the pump at the well bottom and a reflection can double the voltage at the controller.