My earthing/Ground pin shows voltage


Thread Starter

Prof R K Gupta

When I measure with multimeter, I see Phase to neutral 220 V; Neutral to Earth 35 V and Phase to earth only 150 V.

When I switch on table top computer or desktop, the voltage in earth to neutral rises to 65-68V.

I have 220V AC single phase supply in my home. This earth voltage is seen in all sockets.

I think earth pin should never show any voltage and neutral to earth should not show any voltage or maybe a few Volts. And phase to earth should show full 220V.

The tester shows dim light when gadgets like fridge etc are touched on their body nuts.

Bob Peterson

Presumably what you are referring to as "neutral" is supposed to be connected to earth at your service point. If so, there is no way the values you are measuring could possibly be true in a single phase system.

It could be a measurement error (or an operator error in taking the measurements).

It might be that there is no actual connection at your service to earth which would make the voltage from what you are calling neutral to earth float.

It is very hard to give you any guidance on this situation without looking at it closely and that is not possible over the Internet. I am not sure there is any cause for concern but if you are bothered by it, you might want to call in a competent electrician to have a look.


If you are reading this at the receptacle without a load plugged in, it is possible that the neutral to ground connection is open and your AC is floating which could account for the strange voltage readings. Check this connection at the transformer or the first downstream first panel.

William (Bill) L. Mostia, Jr. PE
SIS-TECH Solutions, LP

Any information is provided on Caveat Emptor basis.
I saw this behavior in damaged wires and some insulation faults in equipments and electric installations. Moisture or water inside the cables runs can also be causing this.

William Hinton

I have heard of this many times, saw it a few times and the causes and solutions were the same.

Some older homes had their ground wire connected to the water pipe. This seemed to work pretty well until the well pump was replaced and the pipe was replaced with PVC pipe.

The second most likely cause is knocking the ground wire off your ground rod with the lawn mower. The ground wire connects to the ground rod with an acorn clamp. This connection needs to be clean, tight and it can not have corrosion. This is difficult when some of them are under ground.

One time it was discovered that the split-bolt connector was loose at the weather-head for the neutral.

That’s about it, I hope this helps,

William Hinton
Retired and liking it
check the neutral & earth wires are connected concern places with out any contact resistance (i.e. loose or rust at terminals).

or may be you need to improve the conductivity of your earth pit, either pouring water or re-install a new earth pit.

Prof .P.Aravindan

It is obviously shown that your earth electrode is open circuited. It is very danger for your equipment and operating persons. Immediately you have to check your neutral earthing electrode with a qualified electrician. The NEV (Neutral to Earth Voltage) should not exceed to 1-5 Volt Max. It would be possible if you properly maintain the earthing of your system.

Electrical Consultant.
[email protected]
The "Neutral" should be connected to the ground at the breaker panel to have a properly grounded system. This will have an adverse effect on your overcurrent devices working properly.

Dr R K Gupta

Thanks for reply. But neutral and earth are not connected together. These should never be. IN single phase supply the utility company provided two wires.One phase and one neutral that goes to supply grid or transformer. Earthing is internal thing where every consumer instals his own earthing pit and ground earthing wire. Hence neutral to earth should never show voltage. In my home neutral and earth are NOT connencted as you mentioned. SO why it is showing voltage. I mean Neutral to earth point of power socket? And this goes high when machine like PC is switched on.

Bruce Durdle

Whether or not the protective earth (PE) and power supply neutral (N) are connected depends on the local supply requirements, and varies considerably depending on where you are in the world.

In my residence, there is a local PE earth connection, and an incoming power supply neutral connection. The transformer neutral is also connected to earth at the transformer. These are connected solidly in the main switchboard. In IEC terminology (see this is TN-C-S. It is also locally referred to as MEN for multiple-earthed neutral.

If there is no local connection between earth and neutral, there may be a small voltage due to voltage drop along the neutral. Find out what type of earthing your local supply system is supposed to use. If there are anomalies, then get the installation checked by someone who knows what he or she is doing - this could be a major safety hazard.
This sounds very dangerous, you must get a competent electrician to check it out, Voltage on the exposed metal of your refrigerator could cause electrocution.

In most parts of the world the neutral and ground are connected together at the panel however where you live (you didn't say) it may be different.
Even I had faced this issue a couple of days back, when in investigated I found that there was a wrong connection (phase connected to earth) in a new spike guard that I had bought recently. Since in one place there was a wrong connection I was receiving phase in earth connection in the entire house. Please check for any wrong connection in the three pin or in any other gadget.
the only way to get the earth line, Inspect the building wiring, check the earth connection coming from, back trace it. It must be terminated to a proper earth pit. You will find and loose/broken connection in earth line or your earth pit is not effective.

If earth pit is not effective, treat some water & salt to the nearby soil area.

If still this point exists, prepare a new earth pit and connect it to your home earth line.

For a good and healthy system,
P-N=220-230v, P-E=220-225V, N-E=3-5V (neutral should be at negative potential). this is standard for India.
It is 8 years past the last answer and the issue doesn't have a convincing answer. Just some changes from the original scenario of this question- I have a 3 phase supply, no ELCB at home, and instead of directly plugging in a computer, I'm plugging in a UPS.

I'm facing a very similar problem. When the UPS is plugged into the system, a tester glows when in the earth socket, my multimeter between natural and earth shows about 65-70v. If I touch any metallic body connected to the 3-pin in my home (water of washing machine, laptop charger ends)- I get badly electrocuted. The water flowing in my washing machine is untouchable.

An electrician did come and check the system. He only had testers and removing the UPS from the supply eliminated the tester-glow when earthed so he left saying the problem was with the UPS that it was giving out supply into the earth pin. I was convinced because we did pull phase-neutral pair (without an earth wire) from the socket into an extension box and then plugged the UPS into it, and the UPS output socket had voltage in the earth pins- so I was convinced that, yes, this shouldn't happen.

My UPS technician who visited me today told me it has nothing to do with the UPS, and he showed something else interesting- Phase-Earth was only ~180v, and that too in his clamp-type meter measured with probes. My Mastech MAS830L multimeter showed like 18v :( I now was wondering why is that happening, my multimeter showed a decent ~230 between P-N, E-N at 4v when no UPS connected and ~65v between N-E when UPS is connected, but E-P showed like 18v which doesn't add up :(

His theories are the below:
1. My Mastech multimeter is wrong that's why it shows 18v between E and P when his shows 180v (which sort of adds up and should be the case)
2. There is a neutral jump in my domestic supply, which when I asked him to explain what I could understand is that some appliances with SMPS that are partially closed or wiring in general when having loose contact or so that leads to a drop in the phase voltage. I am still scratching my head trying to make sense of what he told me. The UPS just amplifies the prob and that it never generates nor can generate an output voltage on the earth pin.
3. There is no earthing in my domestic supply- for this, we pulled a wire from my main db to my nearest 3-pin's socket and checked for continuity with my multimeter- tried in ohms, kilohms, and nope, the circuit was open- so no earthing.

After he left, I tried connecting my UPS to another room and voila, the output socket's earth pins didn't have any voltage!!! I was dumbstruck...

Any leads on how to go about this? I'm currently based out of a tier-2 city called Tirupur in the south of India and getting hold of a technically sound technician seems hard, hence DIY is what I'm thinking to be practical. If anybody can help me understand the theory of what might be going wrong, that'd be really helpful.

Thanks upfront!
Actually, I believe you should republish your problem as a new Forum Topic! This one is so old and long, many members will ignore it!
PS: How close are you to Pakistan?
Regards, Phil Corso
Thanks, @PhilCorso I've republished it as suggested into a new post with a representation of the problem, my debug steps and some of the conclusions I drew out of it.

PS: Air distance is 1.6K km to the closest land border and 2.3K km to Lahore. Why'd you ask?
I was there in Dec, 1980! Did an Electrical System Review of the Daharki, West Pakistan, Fertilizer Plant. I was an employee of Exxon Chemicals at that time.
Regards, Phil Corso