Voltage Between Neutral & Earth

#1; maybe one phase is grounded through your load. perry

What voltages are you getting to earth for each of the phases?

Does your generator have a floating neutral or is it bonded directly to the frame of the equipment? It is important to distinguish between the equipment safety ground (bonding) and the electrical system neutral (possibly current carrying).

Where is the 230v, at the generator, or 100meters away at the load.....?...?

Your neutral could be open, and showing a reading because of capacitance...!..?

Cheers

Mark N.

Would that be a super-dooper DVM or a cheap-and-nasty moving coil voltmeter? That sort of reading on a DVM may simply be an indication that the neutral is not earthed at the generator and that there is an earth leak somewhere on one of the three phases near the load. Does a filament lamp light when it is connected between neutral and earth <repeat question; previous applicants need not apply......>

I do believe that earth and the neutral should only be bonded at the generator. The frame should/could be physically earthed with an earth pit, which is to my mind a really great idea......

I do feel that 100 meters away, that if its showing such a large voltage difference that probably something is wrong. But I am fully prepared to be wrong as well!!

If the loads are fairly evenly distributed (if 3 phase), you should only see a few volts of difference between neutral and earth even 100 meters away......I reckon that you have a wiring or cable fault......

Warning, it could also be dangerous!

First: take a 240V lamp and connect between the neutral and Earth to see if it will glow If the blow is visible (or you can check the amps), then you have a fault downstream (i.e. on the load side), between a phase and earth.

The normal methoad is to have the neutral from the generator, grounded to a separate ground, as near as possible to the generator. The grounding of the generator metal body is a separate earthing from the neutral. there should be a protective system that will shut down the alternator if there is a leak from the output phases to the chassis of the genset.

If your case is well understood, you have a missing connection between the neutral point at the genset and the ground, AND you have a possible fault on one of the phases, leaking to a ground link somewhere on the load circuit. The fault could be resistive, or through some device like a transformer or lights circuitry, with one end grounded either by mistake or because of an insulation fault...

Its dangerous. Have it checkedby an qualifid electrician. Thwere may be leakage.

The generator should be grounded at the generator. This establishes the voltage reference point for the system. The distribution panel(s) should also be grounded at their location. This ensures that the entire system is operating with the same zero-reference. Is the Neutral bonded to the frame of the generator? If not, it should be as this constitutes a "seperately derived system". See article 250.35 of NFPA 70.

The Neutral point at the Generator should be grounded and preferably at a separate groung from the generator body's ground. This will allow you to install a tripping device in case of a generator internal fault and prevent a fire or much bigger damage.

As usual, Anonymous is showing their ignorance, or is it arrogance.

This is the last time anyone should try to help an "Anon".

They will/do not even try to help themselves with a simple reply.

Sincerely.

Mark N.

Yes

At least he should respond to one of the comments that are trying to help him!

Well, from the start, his entry shows that he is ignorant of the minimum required to be doing anything near a genset, or trouble shooting it.

The best response is either to ignore such OPs, or just send them to get professional help. This particular one seems not interested in the answers he got or unable to understand them...

I am sorry gentlemen. I was away and not able to read the great suggestions. I am checking the system for possible ground falult. The system neutral is earthed separately. But I am not sure the condition near the genset. I will get it checked up as well. Thank you for all the help. I will come back and post the identified problem. Regards.

Mark N, I know that you do not want anyone to help, but there is a reason to help.

He has asked for assistance, in some cultures, it is very embarrassing to respond, that may be the reason for no responce, mind you I have not come across it several times, only ocasionaly, and not on this forum. The preson may be embarrased about the real reason for the fault, dont be to hard on the guy.

Anyway for my uninformed guess as to why you get 230 volts between N + E is because the generator should have its own earth stake and be bonded with the netural, as this is a supply not a sub circuit

Regards

Joe