Floating Neutral

With the only load on the line being a high input impedance voltmeter you can get all sorts of unusual voltage readings. Then again you might have a more serious problem like excessive leakage paths from a shoddy installation (dirt, broken insulation, salt or other electrolyte water, etc.) or even faulty equipment. Identify your neutral grounding standard for your location. You should also realize that you always do have a neutral grounding resistance, regardless of somebody designing one in. If no resistor or cable has been connected between Earth and neutral then the cabling insulation resistance between Earth and ground will also exist between your hot wires and ground.

Disconnect all the wires, then check again when the wires are empty.

Isolate the supply and have the installation inspected for safety by a qualified Electrician before re-energising, Agnes. You know it makes sense.

if you have 3phase lv system, do check L-N and L-ground. Do not short to ground if you have leakage voltage like this, it dangerous. Some earth point may be connected on body of device. Make sure everything safety

Friend,

If you have a 120-volt (or similar) incandescent light bulb in a socket with leads, you can connect it between the neutral and ground. It will provide a fairly low resistance path between the two. If you have a truly faulty system, this bulb will light; but if you just have a lot of impedance or capacitive coupling then the bulb will stay dark and the voltage you measure will be much lower.

My opinion is that this new system does not have a properly grounded transformer at the source (neutral tied to the transformer frame and both bonded to a good ground (rod, buried structural steel, or similar).

--JMM

Thank you very much. today I have called the Electricity Board persons to check their neutral and whether it is grounded properly or not.

Regards,

Gowin Pande

If you're calling the electricity board to check the transformer why are you suggesting in a later post #8 you are planning to ground the neutral.

If the transformer belongs to the EB it is not your responsibility. Don't interfere with it.

You are right. But, EB person has also suggested the customer to earth the neutral.

Thanks & regards,

Govind Pande

Sorry, but it is the electricity boards responsibility to maintain an effectively earthed (grounded) neutral. Stand your ground on this (OK a bad choice of words).

You start taking responsibility and any later problems, accidents or what ever, become your problem. A problem that could land you in a court of law.

Do you have this request to provide the neutral point earthing from the electricity board in writing? I very much doubt it, they aren't that stupid.

Drop the whole idea.

Put the ball back in the electricity board's court.

I'm not criticising you, I'm trying to keep you out of a whole heap of trouble and litigation.

I think it might depend on where you are located. In Australia, every consumer has a MEN (Main Earth Neutral) link, connecting the neutral to the earth at the switchboard. From what you are saying, it's obviously different in different countries.

It would help if we knew the location of the OP. And that's up to the OP to let us in on the secret.

That said, from the figures given the electricity companies earthing arrangements aren't really up to the standards one you would expect for a new project.

I personally faced such problem then i used a separate earth pit for the grounding the neutral and problem get sortout

thanks. I have also got the similar plans to ground neutral to a seperate earth at the source.

Regards,

Gowin Pande

I have experienced this a few times in my life. It is my opinion that you have an open short in one of your primary lines. Each time I saw this it was the insulation on the wire was damage where it passes through the panel to the meter base. Since the primary is fused behind the panel by the power company, you are not creating large enough short to cause any concerns for them. You have proven this by your statement that "no load is connected yet" . I am assuming you have the main disconnected. If true, your meter should be turning, indicating you are using power. If it is, you have a shorted primary. In addition the panel is most likely warm to touch!

Best Luck!

during project We have same problem in output of our UPS which neutral is floating and we decided to use isolation transformer and grounded the neutral on secondary side .