Generator question

[John White]

I have two Harbor freight generators. I was checking the out put with a vom meter and here is what I found. On a house hold recpticle you have three plugs. One is ground, one is netural and one is 110-120.(hot) In checking both generators I find that one terminal is ground and 60 volt on each of the either two terminals or 120 when checked together. Some one said that these generators are designed to only run power tools, and will even damage some of them, if they have any diodes in them. And said never plug any thing electronic into them. I have two other older generators and you get a 120 volt reading when you connect between hot and netural or hot and ground. I am wondering if any one else has checked their China made generators. Maybe some one else more elightned can answer this question.

 

[scoops]

I have a harbor freight , and it measures 120 volt at the outlets.
I've never heard of 60v at the outlet.
Plug a 60 wat bulb in it and see how it lights.

 

[JB4310]

I've never heard of that before.

I did have an odd issue with a small 3500 watt genny. it had a 220 outlet but it did not put out 2 even 110 volt circuits. so you could not feed a split phase panel. I found out the hard way by burning out a garage door opener control panel.

It was designed for 220 volt loads, but not two 110 volt loads.

When I checked the output, one hot leg would be 180 and the other would be 40. It would float around. 220 volts between the 2 hot legs, but varying between each hot and neutral.

I have never heard of my problem before or since.

JB

 

[travis potter]

Did you buy the units new or used? If new takem back.

 

[yelbike]

What you have is called a floating neutral, which is standard on most newer gen sets. What problem is it causing you?

The problem that some people have with gensets damaging power tools useally stems from under sized gensets for their particullar needs. For example if your circular is slow at start up is bc the genset can't keep the voltage high enough which lets the current rise, which in turn creates too much heat and eventually burns out the motor winding in the saw. The same saw on a larger genset will work fine as the voltage will stay at rated levels and cause no problems.

Also the problem with the electronic having issues has more to do with un pure sine wave coming from the recitfier which is again letting the heat build up. Useally you get what you pay for.

Hope that helps.:confused2:

 

[Garybake]

Portable generators have different frame or third prong grounding or bonding (not earth dependent). Some can be changed in outlet socket.
This may help.
Gary

http://www.osha.gov/OshDoc/data_Hurricane_Facts/grounding_port_generator.pdf

 

[Garybake]

Misinterpet question on previous post I think. Low voltage is because noload is sensed by governor/output with DVOM. Circuitry in plug config is diffrent from houshold as they are isolated from earth with rubber wheels/feet not ground rod or plumbing. With household hookup and ground rod is installed tang in recepticle is usually suggested popped.
Hope I did not make it worse for you.
Gary

 

[RPW]

If my understanding is correct the Navy has used a similiar setup on there ships for years. The idea is that you won't get electrocuted as easily with 60v to ground verses 120v. I don't want to test the theory. If that's true then it was done on purpose because gensets find there way into unfriendly territory with wet ground etc.

 

[Craig Clayton]

I have a 6500 peak / 5000 watt Coleman generator Floating Neutral generator.

yelbike is correct about the generator sizing

I am a licensed electrician and I took 1 year of generators as a college course
With John Whites OP I am confused with the supplied info
The generators might have some form of open circuit voltage regulation ??
I would you suggest you plug in your kitchen non electronic kettle filled with water and do a load test.
You can not hurt a resistance based kettle at 120 VAC 60 HZ.

Craig Clayton

 

[yelbike]

Gary either way your correct. Sort of...anyway. He has 120V from hot to neutral just not to ground so its not a sensing issue. You said it correctly when it comes to the bond terminal is not grounded in the receptacle. The reason for this is they are allowing for an external ground (ei..ground rod) for a permenent installation. If all your using the genset for is temporary and portable power you can ground the bonding terminal in the recepatacle or.........

If I've confused you (and myself :confused2 forget every thing I said above and do this:

Make an adapter with an old extension cut the female end off. Now use a GFI receptacle put the black wire for the cord to the gold screw terminal on the receptacle, put the white wire on the receptacle' silver screw. Put the green wire on the green screw. Now add another wire for the ground terminal (green) to the neutral (white) terminal. This now becomes your "system ground."

Now when you plug your adapter, you will have ground fault protection and you'll overcurrent protection will come for the generators either fuse or breaker.

And the navy 60v is not about safety. You are probably thinking about the cathodic protection system which is another tread for another day after another beer.:drink:

Wow that was long now I need a beer:drink:.....and spell check!!:drool: