Howdy.
Geezer over on the bike group says that I should ask you.
I want to connect a genny to my house. Got the isolating switch in, but the genny has no neutral. I don't want to fry the gubbins in the dist board. I've see here stuff about grounding one phase (to fake a neutral?) but here in Spain we don't have PME and ground+anything trips the rcds.
Any idea?
Cheers in advance.
Hi
Sure the genny has "no neutral" and not "no earth"?
The usual trick is to fake an earth from the neutral of the genny (should you need to).
A few details about the genny will help.
Cheers
He might be talking about a 3 phase genny Adam?
Bob
I think the idea is to connect that earth terminal to an earth spike and that provides an earth for the sockets.
When I fire it up and poke my neon screwdriver in the socket, both terminals light it up.
See picture. I say there's no neutral because both terminals light up the neon screwdriver.
More likely Spanish electrics that label the both the Live and Neutral as Lines.
Lets see what info the OP can post about the genny. As the genny is for a house it will still need a neutral (unless the Spanish are using 400V lamps)
Plugs and sockets are not considered phase-sensitive ie; the plug can go either way up. But the genny isn't Spanish. I think it's Chinese.
It's not "for a house" as such. I bought it to use on site, but now the house is finished I thought I'd use it for a backup supply at least for office/freezer.
Portable gens have a neutral, its whichever of the 2 power output terminas you connect to ground. They don't have an earth, a house needs that. If you have a local earth rod , that's already covered, though its best to also connect earth to (genny) neutral. If no local earth rod, its easy to fit one as a supplementary eart h. You can't rely on a supplier earth when power's off.
NT
I'm not sure I understand any of that.
The genny has two "normal" socket outlets including earth connectors.
There is an earth terminal connector on the chassis (see photo in other post).
Both lines light up the neon screwdriver.
I don't know what a "supplier earth" is. The house has 6 earth spikes under the extension which are also connected to all the steel reinforcing in the concrete base.
There is no PME here. Touch the neutral to earth and the RCD trips immediately.
I'm going to inspect the genny wiring to see if the earth terminal is internally connected to one of the lines.
Of course if there's no ground reference. You are acting as ground as far as the neon is concerned.
If you rig up an isolating transformer (building site, etc) fed from UK mains both of the output terminals on that would light up a neon too.
Right. Inspected.
One wire from the earth terminal goes to the earth connectors in the sockets. Another goes off to the generator.
Coming from the generator we have black and brown at 12v and blue and red at
220v.I still don't know how to get a live and a neutral from what appears to be true AC at 115-115 but without a 0.
Confused.
Does the Cupper Winding help you make tea?
Some 110V sources are split either side of earth. I have no idea of this is the case for your genny, on either/both the 230 and 115V settings.
Personally, I would earth the earth lead to your house earth. Depending on how you use it, that might happen anyway.
So are you saying that if I connect the genny earth to the house earth I would suddenly get a live and neutral as opposed to two lives?
I was going to connect a plug to the house side and plug that into the genny, which would include an earth connection. But I don't know how to wire the plug if I don't know which wire will be "neutral". I suppose I could connect the genny earth terminal to a nearby earth spike, fire it up and see what happens.
That is lethal and known as a widow-maker. You clearly have no idea what you are doing. Stop right now and get local knowledgeable help.
Have you measure between lines and earth? And checked the earth pin is connected to the genny frame?
I thought those connectors did specify neutral and live?
You might find the generator winding is centre tapped to earth. This is what's done in the UK with 110 volt tool transformers. This means that there is 55 volts to earth on both poles.
If your neon lights up on both poles, it sounds likely.
That's called a Jesus Cord.
Because when you pick up the wrong end, you either yell "Jesus" or you meet him.
Seriously - stop it now. You're dangerous.
One other factor you may need to consider is that it is unwise to rely on the supplier's earth during supply failure - indeed, if the supplier has a nuetral fault and you're on a TN-C-S (also referred to as PME) your supply earth may drift quite some volts (10s, 100s if you were really unlucky) above nominal earth outside your house.
The usual route here is to put an earth spike or two in and bond that to the MET - but as this connection may become a route for current in the event of certain faults, it needs special consideration to do it correctly.
And no, you cannot switch the house earth between the supply earth and your local rod when you are using a generator.
At the risk of repeating myself, I don't know what a supply earth is.
I'm amazed that I have a 220v generator with no way of connecting it to my house (with it's magnificent earth).
Oh, and I've already said about 3 times that we don't have PME here.
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