Floating ground / non complaint ground

Electrician who came to install my new panel referenced a product in the market which continuously tracks ground. In fact he showed me the app showing ohms value of the ground in place. Its quite useful to know.

In any electrical circuit perhaps the most critical aspect is having a good ground. nEC codes here in US call for < 25 ohms. Now, accidentally, nature, corrosion, landscapers, etc often cause havoc to those underground ground rods. I know there is the bonding to the water mains also but water and corrosion are darn good buddies. The bigger problem: no one will EVER come to know grounding is gone or non complaint anymore. So having Sense notify users that it found insufficient grounding will be really useful.


By insufficient grounding I meant if Sense is capable of monitoring the resistance of ground. Sense is grounded I know. So if it finds the ground resistance > 25 ohm, triggers an alert for the homeowner saying something probably wrong with the grounding.

I’m not sure Sense gets has the needed measurement points to measure ground resistance. As I remember it the Sense monitor doesn’t attach to the panel ground (just the L1 and L2 hots plus neural), plus the Sense monitor has no access to the earth ground reference.

Ah really? Thought there was. Let me check

Closed. No ground but in main panel if installed neutral is bonded to ground so should be doable.

Even if the neutral was bonded to ground, Sense would still need a low resistance connection to the earth ground to measure the resistance. That’s the reference point.

Correct. I feel (maybe am wrong) but Sense probably already has that capability.

For this to work, the sense meter would have to be made of metal or have a ground to attach/ mount to the panel/ ground and then the neutral could continual test for continuity between N and the grounding. The labs section within sense will alert for a floating ground for when the landscaper knocks the ground off the rod or a geeker cuts steals your ground lead. If this happens your L1 L2 phases drift back and forth and the sense meter should notice that fairly quick. As far as the panel loosing its bonding and exceeding 25 ohms after its wired up… It shouldn’t but I have seen it. I’ve even seen it arc between the bare copper and the moist panel.

But without the sense meter connect to the panel or at least an independent ground… It cant measure the ohms difference without being connected to both.


And this where my 25 year old engineering degree fails me. Damn it: should have paid more attention in 3rd or 4th semester instead of swinging those beer pongs!

Well explained yes: needs some sort of ground. Over and above the neutral.


I thought I was the only old man in this message board.

I did my engineering when I was 17. LOL