High Face to Earth and Neutral to Earth Voltage from Generator

How can be neutral to earth voltage 110V (same as phase to earth ) ? and its normal as per manufacturer ?

Dear Friends,

what I said is actual facts.

But how to prove that the generator is faulty or to reduce the face to earth and nutral to earth voltage, is my problem.

Any good advice will be greatly appreciated.

Reduce the supply voltage to 2V.

great idea !!

Mr Jayadev,

Why you want to reduce phase to neutral voltage. What is the rated voltage of generator. If you are in India single phase voltage(to neutral) is 230 V .

Check whether any short circuit between phase and neutral. Because you are getting the same voltage as in phase on neutral also. But in this case phase to neutral voltage should be zero. Neutral to earth voltage will be same as phase to earth voltage.

Looks like you've bought a 220V centre tapped generator instead of 220V end tapped.

Expensive mistake.

Probably he would be able to shift the neutral (center tap)? Or not use it and make the full coil work - remove neutral from the outlet (or better - on the generator end)

Re wire the outlets and use one 240? Isn't that possible?

The center tap of the 2 windings must be brought out to an earth point some where . It is an unusual method of earthing I can not see the reason for it, unless there is some weird regulator system using 110 volts with a ground circuit.In which case removing it would not work.

Re the UPS it operates on dc from a set of batteries so all the AC input does is charge the batteries and supplement the DC required for the UPS, I do not see that this circuit would be too voltage sensitive or even if the frequency was off slightly why it would stop the ups working. Although if the UPS ground and the generator ground were the same it could be dangerous to see 110V relative to both inputs floating around on the system.

Double check this 110v ground with a test lamp if it does not light the lamp it is probably a capacitive effect not a true ground.

Point of clarification; it's phase, not face.

Cheers

Are you using a high impedance digital voltmeter or a low-impedance moving coil analog one, Boss? Which?

connect one end of generator to earth then only you can term the other end as phase. if both the ends are open this problem is faced.

Ramesh, Kolkata.

Got to agree..

Jayadev, is the generator earthed, if you haven't then do so, as this type of gen set requires earthing... and read the handbook!

Dear Friends,

Thanks for your efferts to find a solution for my problem. Greatly appreciated.

Shall try the options and come back with the results.

If the generator is centre tapped earth. Earthing one end without removing the centre tap will be a death sentence to the generator.

Mr.Jayadev,

You have two different problems. Let's take these one by one :

1.APC 500 VA UPS will not work on portable Generator Supply due to High Distortion in DG Supply Voltage Waveform and / OR Generator Frequency falling out of acceptable frequency window of 47 to 53 Hz. As the Generator gentleman to adjust the frequency at about 50 Hz and if the UPS doesn't work despite this; reduce the UPS sensitivity to `Low' (refer UPS Manual for this). If it doesn't work still, connect one 20 MFD / 440 V AC capacitor in the Input Socket of the UPS. It should work.

2. Neutral to Earth Voltage is just a reference and is no way an indicator of EARTH being Good or BAD. The wall socket Earth point should go to a Good Earth-Pit during Mains as well as DG Mode. Even though the Floating 110 V you are witnessing between Phase to Earth OR Neutral to Earth is not detrimental (subject to the fact that your wall socket is going to good earth pit); if you still want this Voltage to be low; you may connect one 6 MFD / 440 V AC Capacitor at Generator Output.

All the Best !

Sanjeev Gupta

Mr.Jayadev,

In point no.2, 6 MFD/440V AC Capacitor is required to be connected between Generator's Output Neutral and Earth.

Thanks & Regards,

Sanjeev Gupta

It appears to me that you bought a cheap generator for the US market, which is center tapped 220VAC, so you get 110VAC from phase to neutral. Neutral to earth should be about 0VAC.

If true, you will need more than your apparently basic knowledge to get it working safely and properly.....as it needs extensive re-wiring, that may or may not be easy to achieve......I cannot "see" the schematic, nor the ohysical connections, but theoretically at least, it should be possible.

You need access to both phases, the neutral and the earth connection.

(I am assuming that you need 220VAC of course for your UPS, standard for India.)

It will be something like this, but you need a good electrician to be certain either way:-

Best of luck. Think SAFE!!!

Also if the generator was made for the US market, it will run at a speed to generate 60 Hz. not 50. If that is the case you will also need to modify the generator's speed governor to the slower motor RPM needed to generate 50 Hz.

Well said!

I completely forgot the frequency!! Shame on me!!!!

If its like my camping Alternator (220VAC 50Hz), there is probably not enough adjustment in the speed control without taking drastic measures.....which I have never needed to do, but it was off frequency (almost 2 cycles) when delivered....a scope and 5 minutes soon fixed that!!!

By the way, a high neutral to earth voltage implies that they are not linked as they should be......dangerous!!! Usually you want as near to 0 volts as possible.....

Please all change the title to something like:-

"High Phase to Earth and Neutral to Earth Voltage from Alternator"

Andy; it's a (1) one, single phase center tapped. the ground (earth) is a reference point

if you have voltage drop in wires, you will measure that voltage to the earth or ground, right! if you had zero load it would measure (0) zero voltage from the neutral to ground

right! Perry

Even with load, as the neutral/earth link must/should be on the unit, you should NEVER be able to measure more than a couple of volts different - max! No matter whether loaded or not.....

Its only in a 3 phase environment, with unbalanced single phased loads AND a reasonable distance to the neutral/ground link, that it can happen that there is a significant voltage between neutral and ground.

That is simply not the case here.

hello jayyadev , you need to check the ups fuse and the voltage if same in genset you have , and the grnd / neutral voltage is normal in generator but you can reduce that to able to put a ground rod of about 6meter if your ground is wet in dry soil you to have 12mters ground rod and added with charcoal and mix by water and salt , to reduce the voltage in you neutral / ground

NOTE : THINK SAFETY !!!

The <... nutral to Earch voltage ...> is a function of the current in the <...nutral...> and the impedance of both it and the <...Earch...> conductors. The lower the impedance, the lower the <...voltage...>. Provided the <...small Generator set...> is connected to a load, the <... nutral to Earch voltage ...> cannot ever be zero, as copper is not a perfect conductor.

Have the whole installation checked-over and corrected by a qualified local Electrician without delay.

Am curious why you answered a 10 year old question?

A perplexing technical issue never gets old....until it is finally solved....