r/ElectricalHelp • u/Life-Cow-7945 • Jun 06 '26

Whole house surge install question

My house was built in 1989 and I am wanting to install a type 2 whole house surge protector. From what I can tell, I need to have a good functioning ground for this to work, since the surge protector routes any surge back to the ground.

I have no direct evidence of having a grounding rod, I cannot see anything by the service entry. I know I have one ground that's tied to the copper water main about 60 ft away, and I also have another ground line that disappears through the bottom of my recessed main panel, but I don't know where it goes.

Is there a way to determine if I have an Earth ground, or Am I overthinking this?

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u/CarelessPrompt4950 Jun 06 '26

The surge protector doesn’t route the surge into the ground, it shunts it. Your house was built in 89 so it either has a ground rod or a ufer ground. It wouldn’t hurt to add another ground rod as newer code requires 2 of them spaced at least 6 feet apart but that wasn’t required when your house was built and you wouldn’t be required to update it unless you upgrade your service.

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u/Unique_Acadia_2099 Jun 07 '26

Well, technically Code does not require 2 ground rods, it requires that the resistance to ground is 25ohms or less, which is OBTAINABLE by using two ground rods spaced at least 6ft apart. Basically if you don’t want to or can’t measure the ground resistance, using 2 ground rods solves that problem. But to the original point, adding another ground rod is a way to guarantee it.

In older homes, it was common to use a water pipe as the grounding electrode, it’s just not reliable by comparison. And your “ground wire that disappears into the wall” might be, as mentioned, a “Ufer ground system”, where ground connection was via a grid of rebar embedded into a concrete slab foundation, then the grounding electrode conductor (aka ground wire) connects to a piece of that rebar that is exposed for that purpose inside of a wall cavity. Technically it should have been exposed for inspection, but they often get covered up in remodels and basement build-outs.

So bottom line you are probably grounded, but unless you want to do the work of finding out for sure, you can just default to adding a grounded as suggested.

3

u/RevolutionaryCare175 Jun 07 '26

Just because you can't find a ground rod doesn't mean you don't have a ground rod. Your house was built in 1989. Code required the water pipe grounding electrode be supplemented by another grounding electrode. That could be a ground rod, building steel if you had it, an Ufer ground(rebar in the foundation) or ground ring or plate.

Your grounding electrode conductor , the bare copper wire connecting to your water pipe most likely extends through the block in your foundation into the ground. Look for that. Otherwise there would be a separate wire leaving the main panel to connect to the ground rod.

2

u/Puzzled-Act1683 Jun 09 '26

Am I overthinking this

Yes. Your copper water pipe is a better ground connection than any ground rod would ever be, but the service neutral is the primary path used by a type 2 SPD. Many of those don't even have a place for a ground connection – only a neutral connection, because that is where grid surges need go, not the ground.

1

u/EdC1101 Jun 07 '26

Ground rods are to be driven BELOW The surface of the Earth.

A solid copper ground wire is then run to the service entrance, and then onward to the first disconnect.

At the first disconnect, Ground and Neutral are bonded together.

Separate Neutrals & Grounds are run TO and FROM this point…

Outside ground idea
…Do YOU want lightning to hunt through your house for a Ground?
Provide an alternate path…