Not earthing a generator

"Sylvia Else"

** An isolating transformer normally only isolates the current carrying conductors from ground while continuing the safety earth connection through to the appliance.

Assuming that a portable generator has its neutral tied to the metal fame of the machine, leakage ( or a short ) from active to the local ground would make the frame live 240VAC.

..... Phil

Though I don't see what that achieves, other than ensure that there's no static build up on the driven appliance.

In this case, the generator has a plastic cover. The only places that metal is exposed are the exaust, and the earthing point.

I'll find out whether its neutral is attached to its earth point when I stop it later on. Damned thing needs to be run in for 20 hours at half load before being used on variable loads, so I've got it warming up the world through an electric bar heater.

Sylvia.

"Sylvia Else"

** You don't see much at all.

** Really .................

** So one can get burnt and electrocuted at the same time.

Oh Phil, you were doing so well. It was too much to hope that it would last.

With sufficient determination, perhaps, if a fault of the particular kind happens to develop in an appliance, the appliance's casing has sufficient contact with ground and one goes out and touches the generator's exaust outlet.

Sylvia.

If it is bqasically a permanent installation, makes sense to drive an earth spike or use the existing one.

Hi Phil

I certainly see your point if the generator's neutral is tied to the frame.

Is this common practice? If so, why?

I'm looking for enlightment, not an argument!

Cheers

Dave.

**Which one did you buy? How much power? Where'd you buy it? I hope you use an inverter style air-con. Regular air-cons are deadly to generators.

--
Trevor Wilson
www.rageaudio.com.au

"Dave Goldfinch"

** I believe it is the norm.

It duplicates the usual " earthed neutral " domestic AC supply and ensures that a short from active to the protective earth of an appliance will trip a breaker connected in the active.

So - if a gene's frame is NOT grounded to real earth, a single fault ( where active leaks to real ground ) could render that frame live PLUS the safety ground circuit of all the metalwork of any connected appliances that use the safety ground conductor.

Absolutely lethal.

** Makes a nice change round here.

.... Phil

Makes sense.

Thanks Phil.

Dave

It's not on my generator.

Which would seem to mean that the output is floating compared with the earth *pin*. That doesn't actually seem like a very good idea.

Sylvia.

After much soul searching I went for a Kipor GS2600 (rated output

2300W), bought from Sparky Direct. It may not (with emphasis on may) have the run-time longevity of a Honda or Yamaha, but I don't need that in this application. I'll probably die of old age before it reaches 50 hours. The twenty hour run-in, while a bit of a pain, gives me a chance to let it burn-in while it's in warranty. I checked with Kipor in Australia, and they claim that spare parts are available for it here.

In some quarters they seem to have a reputation for being a bit smokey, but in fact once mine has warmed up, there's no smoke visible even if I set out to look for it.

Yes, it's an inverter air-conditioner (Daikin). I called Daikin and they hadn't a clue about starting current, so I measured it directly. It's very well behaved.

I did some more searching regarding earthing. This seems to be a contentious and hotly debated issue.

Sylvia.

heatwaves, I've acquired a generator.

in the ground.

would appear to be pretty well insulated

off an isolating transformer.

some interesting reading here:

If your generator walks, it may pay to anchor it in some way, if you end up earthing it. Perhaps even an earth anchor :-)

Cheers Don...

======================

--
Don McKenzie

Site Map:            http://www.dontronics.com/sitemap
E-Mail Contact Page: http://www.dontronics.com/email
Web Camera Page:     http://www.dontronics.com/webcam
No More Damn Spam:   http://www.dontronics.com/spam

These products will reduce in price by 5% every month:
http://www.dontronics-shop.com/minus-5-every-month.html
http://www.dontronics-shop.com/ics.html

Bare Proto PCB for PIC or AVR projects?
"I'd buy that for a Dollar!".

Yes, having it walk onto the back of someone's truck is a particular concern, and one that I've yet to resolve to my complete satisfaction.

Sylvia.

Heavy metal strap bent into a U, two holes through it, then drive a large pin through the holes into the ground. I make pins out of 1" reo bar and a large washer. a number of those will slow down a stupid thief.

.