Reverse Polarity

[AllanG]

I want to use my Honda EU10i generator to charge my batteries onboard my Legend 306, however, when I connect the generator to my shore power socket, the Reverse Polarity light on my boat's main switchpanel comes on.

I have checked all the shore power wiring from the socket to the electrical panel, as well as the lead from the generator to the shore power socket, and all are correct, i.e. live / neutral and earth are correctly connected.

Can anyone shed any light on where the problem lies, could the generator 240V outlet socket live and neutral be incorrectly connected?

It should be noted that there is no polarity problem when the boat is connected to a marina shorepower, using the same cables.

Any help would be greatly appreciated.

Many thanks, Allan

 

[savageseadog]

It might be because the generator itself isn't earthed. There should be a terminal to connect the generator to an earth which is either a metal spike in the ground or a metal plate in the sea.

 

[tangofour]

There is no physical difference in an AC signal to make one Live and one Neutral.

I suspect that your generator does not have its Neutral connected to the frame ground ( for vey good reasons ) so your reverse polarity detector detects the floating Neutral.

 

[AllanG]

[ QUOTE ]
It might be because the generator isn't earthed. There sould be a terminal to connect the generator to an earth which is either a metal spike in the groung or a metal plate in the sea.

[/ QUOTE ]

As my boat is kept on a buoyed river mooring, is there anywhere on the boat that I could earth the generator to?

 

[AllanG]

[ QUOTE ]
There is no physical difference in an AC signal to make one Live and one Neutral.

I suspect that your generator does not have its Neutral connected to the frame ground ( for vey good reasons ) so your reverse polarity detector detects the floating Neutral.

[/ QUOTE ]

Does this mean that I could still use the generator safely onboard to charge my batteries, even if the Reverse Polarity light is lit, or should I try to earth the generator, (if possible)?

 

[Flossdog]

Am really interested in the replies as I am about to purchase the Honda EU10i and am trying to justify the huge price diff with other gennies. Apart from the above problem, would you recommend this gennie Allan?

 

[shmoo]

[ QUOTE ]

There is no physical difference in an AC signal to make one Live and one Neutral.


[/ QUOTE ]
Are you quite sure about this. (In UK at least our) supply is not "balanced". Live is, well, live and neutal, well, isn't.

Try measuring voltages between Live and Earth (expect 240V) and then between Neutral and Earth (expect a few volts do to voltage drop back to substation)

 

[savageseadog]

[ QUOTE ]

Are you quite sure about this. (In UK at least our) supply is not "balanced". Live is, well, live and neutal, well, isn't.


[/ QUOTE ] Yes Neutral is usually earthed at the nearest transformer, technically Neutral doesn't exist until this earthing is done, so there is a considerable difference between Live and Neutral. I think, however, the point was being made that the generator is free floating so there is no difference between live and neutral. Which is why the reverse polarity light is on. The panel is detecting that there is 240V to it but nothing from live to earth.

 

[tangofour]

[ QUOTE ]
Does this mean that I could still use the generator safely onboard to charge my batteries, even if the Reverse Polarity light is lit, or should I try to earth the generator, (if possible)?

[/ QUOTE ]

The Honda generator is a plastic 'suitcase' type, naturally there is no way for the unit to be 'earthed' unless an earth spike or something is employed. If an earthing point is provided ( cant see from the honda website ) I would make sure that it was connected to the earthing system of the boat. Otherwise I can see no reason why you cant just use the 'reverse connection' light to let you know that the genny is still running /forums/images/graemlins/smile.gif

 

[hairbox]

Hi I have the 2000w model and yes there is a separate earth stud on the genny.

 

[nedmin]

you could connect a flexible cable to the earth point and other end to a piece of copper pipe with a jubilee clip and throw it overboard.the copper pipe I mean!this wouild give you a good earth point.

 

[AllanG]

[ QUOTE ]
Am really interested in the replies as I am about to purchase the Honda EU10i and am trying to justify the huge price diff with other gennies. Apart from the above problem, would you recommend this gennie Allan?

[/ QUOTE ]

Apart from this slight 'problem', the Honda EU10i is an excellent gennie, very quiet running, and I would thoroughly recommend it.

 

[AllanG]

[ QUOTE ]
[ QUOTE ]

Are you quite sure about this. (In UK at least our) supply is not "balanced". Live is, well, live and neutal, well, isn't.


[/ QUOTE ] Yes Neutral is usually earthed at the nearest transformer, technically Neutral doesn't exist until this earthing is done, so there is a considerable difference between Live and Neutral. I think, however, the point was being made that the generator is free floating so there is no difference between live and neutral. Which is why the reverse polarity light is on. The panel is detecting that there is 240V to it but nothing from live to earth.

[/ QUOTE ]

When I asked my local Honda generator dealer this afternoon about this problem, they said that all I had to do was to 'link' the Neutral terminal to the Earth terminal inside the normal three pin UK outlet plug.

I would appreciate your, or anyone elses, opinion about this solution? Would it be safe?

 

[Gumpy]

I have done this on my genny.
It is safe provided that Honda say its OK as some gennys get a bit upset if you do this.
Do you have an RCBO/RCD fitted in the boat system if not its better to leave it as is and ignore the light.

Julian