Connecting Honda EU20i generator to shore power system

[grumpy_o_g]

Yes but what do you deduce about the earthing, or otherwise, of what is normally the neutral from that diagram?
Can you deduce that it is the equivalent of an earthed centre tap?
Or do you deduce that the system is floating with no earth bonding?

I can deduce that that diagram doesn't tell us

 

[VicS]

I can deduce that that diagram doesn't tell us

Hence my comment in post #8 of this thread

 

[LadyInBed]

Yes but what do you deduce about the earthing, or otherwise, of what is normally the neutral from that diagram?
Can you deduce that it is the equivalent of an earthed centre tap?
Or do you deduce that the system is floating with no earth bonding?

From what I can make out it is floating (like a house lighting circuit?)

 

[VicS]

From what I can make out it is floating (like a house lighting circuit?)

Yes i think I agree with you that it is floating.
But not like a house lighting circuit. That like the rest of the house has the neutral grounded ... its the same neutral. Also the earth, protective conductor I think they call it, should go to a terminal in all the switches and ceiling roses.

if it is floating it will explain why some "polarity" checking systems will indicate a fault ..not one due to reversed "polarity" but due to the absence of a neutral.

If that is so then the "fault" indication will be cleared by connecting the conductor that should be the neutral to what should be the earth in one of the connectors as suggested by Pagetslady in #5

If the power supply was from the shore via an isolating transformer one side of the secondary winding would be connected to the boats earthing system Usually the DC negative and anodes etc or the hull in the case of a metal boat to create a local neutral.

Doing what is suggested will be the same provided the shorepower earth is bonded to the DC negative etc.
That would seem therefore to be the correct thing to do provided it causes no problems to the generator.
Perhaps the front panel earth terminal should also be connected to the ships earth.

On the other hand if using the generator ashore one would not create a local neutral, one would use it as it is, although hopefully with the earth terminal connected to an earthing rod.

 

[LadyInBed]

But not like a house lighting circuit.

I wasn't sure when I suggested it

Perhaps the front panel earth terminal should also be connected to the ships earth.

If I was going to connect an earth that would be my choice.

 

[GrahamM376]

Can we get this back into laymans terms please? When I suggested that polarity could be reversed when using a 2 pin plug into the generator, this was disputed. I was looking at it this way:-

In a normal UK domestic circuit, the way most of our boats are wired, the live is on the right (looking at the face of a socket) and the neutral on the left. Connecting a 3 pin plug into a generator will give the same result.

However, if using a 2 pin continental plug, which can be plugged into the generator either way, there's a 50/50 chance that the live and neutral are reversed at the socket - live is now on the left, neutral on the right.

We told by many that all the metal bits on the boat should be earthed to the deck socet earth. Some also say that earth and neutral should be connected together. However, if using a continental plug inserted the wrong way round into a generator, this would mean live is connected to the metal bits = a very bad day when you get hold of say the tap or toe rail.

Where is my thinking wrong?

 

[VicS]

Where is my thinking wrong?

Lady in Bed and I both believe that the generator output is isolated from earth.
We do not believe that one conductor is earthed (to create a neutral) and therefore there is no "live " as such.
So with the reversible two pin connection it makes no difference which way the plug is inserted. Neither is live, neither is neutral. It is an isolated, or "non polarised", AC supply.

No "metal bits" should be connected to either conductor anyway . ....... Although perhaps with conventional British style fittings and wiring within the boat, intended to be used with a polarised supply, one conductor should be earthed at the point at which it is connected to the boat's shorepower system to create a neutral, and live.

If an isolating transformer is used on a shorepower connection its secondary winding is isolated from earth but a neutral is created on board by earthing the "left hand" conductor

If the boat is wired to operate on a non polarised supply then this need not be done... should not be done perhaps.

 

[GrahamM376]

Thanks for that. So, can I check whether it's polarised or not, using a multimeter?

 

[Tamer11]

I intend to run a similar setup on my boat. Could anyone recommend a good generator, should I go for petrol or diesel? It is for a 3 person live-aboard and will be run daily to charge batteries, heat water, run fridge, charge laptops etc.... power TV, how long will I have to run the generator for and what size should I go for?

I am also looking at Goalzero solar powered generator, does anyone have any experience of them in the UK?

Compare Portable Power Stations/Goal Zero

 

[Graham376]

Far better to install solar panels and increase battery bank than run a generator, which is the quickest way to piss everyone off in a quiet anchorage. Our Honda very rarely used. Personally, I find the solar powered generators a bit pointless for boat application.

 

[ashtead]

Curious as how much solar you might need compared to a Honda though ? I’m interested in a panel but would be a flat deck version so which make is the quality equivalent for panels -it seems easy with a generator to choose a Honda but panel makes seem confusing . I feel I must take the plunge though one day .

 

[Graham376]

Curious as how much solar you might need compared to a Honda though ? I’m interested in a panel but would be a flat deck version so which make is the quality equivalent for panels -it seems easy with a generator to choose a Honda but panel makes seem confusing . I feel I must take the plunge though one day .

We've managed for two years on mooring and anchor without running the generator, with 320w of solar +450ah domestics powering fridge 24/7, charging laptops, tablets, phones etc., and TV for a couple of hours in the evenings. Kettle provides enough hot water for pot washing and we use solar showers. If Honda used for battery charging it's pretty quiet but can still be heard on a quiet day from maybe a hundred metres away. If powering the immersion heater or microwave, it's noisy.

 

[PaulRainbow]

It is very important to remember, if fitting any generator and connecting it to the onboard electrical systems it absolutely must have the neutral and earth bonded at the generator. Failure to do so will mean the onboard RCD will not trip. The generator chassis should also be earthed. The vessels onboard earth circuit must be bonded too, how this is done will vary, depending in general on the hull type. GRP boats must have continuity between the vessels earth circuit and its grounding plane (if it has one, most don't) or the hull anode. Basically, there has to be continuity between the earth circuit and the water in which the boat is floating.

In a fixed installation the best place to make the bonding connection is internally at the generator, if possible. In this case, equipment should not be connected directly to the generator, but only to the onboard electrical systems.

If it is not possible a dedicated cable should be made up, where the connection is made inside the plug that fits the generator. This cable must be clearly labelled "Generator only" , it must only be used for the generator and no other cable should be used in its place.

If the generator has two outlets these are usually just paralleled inside the generator, if so, no need to bond both. If bonded and one outlet is connected to the onboard systems, do not connect to the other socket, connect only to the onboard systems.

If the generator has been bonded do not directly connect devices to it, connect to the onboard electrical systems. If you have made a bonded cable, do not connect devices to the cable.

Not all generators can have this connection made, so check first and if it cannot be made, do not connect the generator to the onboard systems.

If in any doubt whatsoever, consult a qualified professional. Generator electricity will kill you just the same as grid electricity.

 

[rogerthebodger]

If it is not possible a dedicated cable should be made up, where the connection is made inside the plug that fits the generator. This cable must be clearly labelled "Generator only" , it must only be used for the generator and no other cable should be used in its place.

I overcome the issue you rase with the need for a special "Generator only came by making the earth neutral connecting within the output socket of the generator.

If like my old honda it has 2 output sockets both must has this connection.

 

[PaulRainbow]

I overcome the issue you rase with the need for a special "Generator only came by making the earth neutral connecting within the output socket of the generator.

If like my old honda it has 2 output sockets both must has this connection.

Yes, that's what i said Roger;

In a fixed installation the best place to make the bonding connection is internally at the generator, if possible. In this case, equipment should not be connected directly to the generator, but only to the onboard electrical systems.

I much prefer this to making cables up, no chance of someone using the wrong cable. It's a legal requirement on all new boats.

There are some issues with dual output sockets, i'll add something to my original post.

 

[rogerthebodger]

Paul

I was not disagreeing with you I was just stating how I did my earth/neutral generation connection.

One thng we do agree on is that its is imperative to have a earth/neutral connection some where on the generator side of the boat RCD.

 

[ithet]

Yes, that's what i said Roger;



I much prefer this to making cables up, no chance of someone using the wrong cable. It's a legal requirement on all new boats.

There are some issues with dual output sockets, i'll add something to my original post.

If the RCD 'test' button trips ok, is this an indication (or not) that the generator earth-neutral connection is ok?

 

[PaulRainbow]

If the RCD 'test' button trips ok, is this an indication (or not) that the generator earth-neutral connection is ok?

No, it's just an indication that the RCD works, but not that it will work in a fault situation. Yes, seems a bit bonkers. To test it will work from a socket, for instance, you need an RCD tester. If you want to check that a generator is bonded, test for continuity between neutral and earth at the generator, with the generator disconnected/isolated.

 

[rogerthebodger]

I have one of these. Also available with a UK plug

This is a typical internal circuit diagram for a RCD.

As you can see the test button connects the live to earth through a resistor to fudge a line to earth leakage so creating a difference in current flowing through the Line and neutral

 

[pvb]

I am also looking at Goalzero solar powered generator, does anyone have any experience of them in the UK?

Compare Portable Power Stations/Goal Zero

No experience of these, but note that it's essentially just a battery in a fancy (and very expensive) box.