Surge protector and ground

Do surge protectors need ground to work correctly? I'm not sure if the MOV requires ground to function. I just think it might be smiler to a GFCI.

Are you talking about ground connections like outside? Or just the AC wall outlet grounded?

Just the wall outlet. Many of the outlets in the house are not grounded.

The inexpensive surge protectors (even overpriced Monster ones) need the outlet ground to be effective. In a high voltage situation, the surge protector simply reroutes the surge to the ground. There are some expensive surge protectors that don't require a ground, but they are not common. Even UPS units require a grounded outlet.

Sent from my cm_tenderloin

The true surge protectors that I've run across will not even allow current flow without a ground.

Hmm, I have an ibar surge suppressor that works without ground. It's a very expensive model. How in the world do I protect my electronic stuff without ground?

Most common surge suppressors are MOV's (Metal oxide varistors) that will become a low impedance when a much higher voltage appears across them--which if it works like intended will shunt the high voltage before it reaches your goodies. They often are connected in various ways both line to line and line to ground, and can even be destroyed in the process of doing their job. Sometimes they will cause a fuse to blow when they get hit with voltage over their rating, and the fuse is a current limiting device so that helps too.

Polty, you'll need a good ground for the equipment to be protected properly.

I prefer a "trident" looking configuration with a total of five copperweld (copper clad) ground rods, 8 feet long, (I prefer at least 5/8" diameter) sunk below the ground at least four inches, the three being sunk a little less than 8 feet apart to allow for connections. Lay the other two across the three sunk rods and connect them with large bronze clamps or use the "explosive weld" to connect them about six inches below the tops of the rods or less if you intend to use the horizontal bars as a bus.

Next run at least a #2 solid copper wire to either under the house if you have a crawl space, or into the attic if you are on a slab. Use conduit to enclose the wire, metal or UV resistant PVC up the wall into the attic. (I prefer 2-0 stranded copper, green insulation.)

Run the lead to a buss inside the attic or under the house and then tie all your grounds to it. With the buss, you are not limited to what size wire you can run for individual connections nor limited to how many leads you run to the outside ground.

Be sure to backfill the holes and trenches so the lawn mower won't find them.

Also, make sure the neutral at the meter base and the ground buss inside the distribution breaker panel is good, clean and well connected, and tied in to your ground system.

I know this will cost a little bit, but the benefits will outweigh the hard work and the alternative.

Well, I can't do that. The current ground for the breaker box is probably only 1/2 inch thick and maybe sticks in the ground a foot. Not sure. House was built in circa '77. The electrical wiring here sucks, some is copper and some is aluminum. Most of the electronics that I want to protect is in the basement room and to the right is a wall where I could in theory drill a hole and add a ground to the outside, but there's a gas line there and I don't know where it's at.

I don't know. I think I'll just hope and pray both surge protectors do there job without ground.

Don't forget that surge protectors protect against surges caused by other than lightning; and don't forget lightning can do a little or do a lot like blow the crap out of almost anything..

I have seen ground rods come out of the ground from a good strike and just leave a steaming hole and broken concrete--

Determining if you should use an external ground on your surge protection devices is pretty simple. If the manufacturer wanted (or needed) an external ground there will be a separate ground stud on the protector itself and will be marked as such. Simply connecting a ground wire to a screw on the device many cause more harm than good. Consult the installation manual that came with the device to determine if it needs a separate connection to ground.
BB

from florida

i tell everyone "if you want it unplug it"
any voltage potential (difference) means trouble
a direct hit means everything will burn
just hope for small ones
constant voltage spikes will take out the mov's
but that is better than your equipment

The sphere of influence of a ground rod is equal to a radius around the rod equal to its length. to achieve maximum grounding efficiency they should be placed 2 times their length apart. If using ground rods buried 8 feet they should be placed no closer than 16 feet apart. Ground rods should be placed no closer than 6 feet from other ground rods or grounding electrodes. (Motorola R-56 Manual Chapter 4)
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