Inverter issues

[Robbie G]

Hi 

I have a new inverter which is not playing , When the boats on mains power the inverter is plugged into one of the sockets and it charges the batteries all fine and well , When I switch the inverter off on the socket , And turn the selector switch to inverter power it trips the breaker even though it’s only plugged in and not switched on , if I physically unplug the inverter input it’s fine , as soon as plug it back in even with the socket switched off it blows the red  breaker 

anybody help with this.  Robbie 

Sorry meant to say RCD breaker not red breaker. 

[Jen-in-Wellies]

welcome to the forum.

Any clues as to which model and make of inverter you have? What you describe seems to be a combined inverter and battery charger, often called a combi, rather than just a stand alone inverter. More info would help us help you with your problem.

Where is the RCD that is tripping? Is it on the shore bollard, or is it on the boat?

Jen

Edited August 20, 2020 by Jen-in-Wellies

[WotEver]

Which RCD is tripping, shore power or the one on the boat?  It sounds like a wiring error but I’m really not sure from your description how you have it connected. Knowing what it is will indeed be a good start, as Jen suggested. 

[1st ade]

Earth loop? An inverter plugged into a socket which is switched off still has an earth connection; if it's earth is different to the external earth it may cause a current to flow which will trip an RCD.

[frangar]

I’m slightly concerned that the Combi is being plugged into a socket....there seems the potential for both shorepower & Combi to be providing 240v at the same time which won’t end well...we could use a model number & pictures/diagram of how it’s wired in. 

[ditchcrawler]

22 minutes ago, frangar said:

I’m slightly concerned that the Combi is being plugged into a socket....there seems the potential for both shorepower & Combi to be providing 240v at the same time which won’t end well...we could use a model number & pictures/diagram of how it’s wired in. 

That was my worry, plug the inverter in to charge the batteries

[WotEver]

48 minutes ago, 1st ade said:

An inverter plugged into a socket which is switched off still has an earth connection

It still has a neutral connection too. 
 

It could be wired reverse phase, it could have a neutral-earth bond that would trip the RCD...

 

Whatever, it sounds like a wiring/installation error. 

[nicknorman]

Is this a Combi (Inverter charger) or an inverter?

 

If it is a Combi there shouldn’t be any plugging / unplugging / switches involved. Who installed it? Did they look at the installation instructions?

 

Sounds a bit like an NE bond issue but the whole installation sounds questionable.

[WotEver]

5 hours ago, nicknorman said:

Sounds a bit like an NE bond issue but the whole installation sounds questionable.

Yup. My thoughts exactly. 

[Robbie G]

The inverter has a 240 volt input for when it’s in charging mode which I plug into the 240 ring main on the boat works perfectly on the ring main when shore power is selected , As a charger If I then select inverter power on the selector switch , I switch the input to the inverter off which is also fine 

 , However and this is the baffling thing, If the inverter is plugged into the one socket which is not on the ring main , but a spare from a socket on the ring main ,  it trips the RCD , Doesn’t trip on the ring main sockets at all ,  the cable is only a couple of feet and in good condition , 

[Tracy D'arth]

So when used as an inverter you have a 13A plug with exposed pins that is live mains?    If so its horrendously dangerous, nay stupid.

[WotEver]

What model is the combi?

[Alan de Enfield]

 

Are you saying that the power 'in' for your inverter is a 13a 3-pin plug, that you simply plug into the ring main powered by your incoming 'shore-line' ?

 

or, 

 

Are you saying that the power 'in' for your battery charger is a 13a 3-pin plug, that you simply plug into the ring main powered by your incoming 'shore-line' ?

 

Where is the 'output' side of the inverter wired into, and how does it get into the 'ring main' ?

 

Is your inverter connected to your batteries ?

Edited August 20, 2020 by Alan de Enfield

[Tracy D'arth]

Will to live?

 

Darwin awards?

[TheBiscuits]

10 minutes ago, Alan de Enfield said:

 

Are you saying that the power 'in' for your inverter is a 13a 3-pin plug, that you simply plug into the ring main powered by your incoming 'shore-line' ?

 

 

That's how I read it, and although stupid it sounds like it works.

 

If it only trips everything on the spur socket, then the spur is incorrectly wired and needs fixing.

 

I'd also want the Combi fed from the shoreline side of the selector switch though - forgetting to switch off the Combi input before switching on the inverter can make Bad Things^TM happen ...

Edited August 20, 2020 by TheBiscuits

[WotEver]

9 hours ago, Jen-in-Wellies said:

Any clues as to which model and make of inverter you have?

 

8 hours ago, WotEver said:

Knowing what it is will indeed be a good start, as Jen suggested. 

 

7 hours ago, frangar said:

we could use a model number & pictures/diagram of how it’s wired in

 

7 hours ago, nicknorman said:

Is this a Combi (Inverter charger) or an inverter?

 

16 minutes ago, WotEver said:

What model is the combi?

 

[Robbie G]

Not sure I’m explaining this very well , yes the battery charger side of the inverter is a 240 volt supply from the sockets on the boat fed from the shore line , The output from the inverter goes through the selector switch to the consumer panel as any other combi , And no of coarse it doesn’t put 240 volt onto a 13 amp plug  ; As this in the input not the output , 

[nicknorman]

1 minute ago, Robbie G said:

Not sure I’m explaining this very well , yes the battery charger side of the inverter is a 240 volt supply from the sockets on the boat fed from the shore line , The output from the inverter goes through the selector switch to the consumer panel as any other combi , And no of coarse it doesn’t put 240 volt onto a 13 amp plug  ; As this in the input not the output , 

Normally a Combi doesn’t need any plugs sockets or switches. The incoming shore power is hard wired to one set of connections and the output to the sockets etc to a different set of connectors. It works as a charger if there is shore power present, passing the incoming shore power through to the sockets, or automatically switches to inverter if there is no shore power present. As far as I can tell, and you are making it hard by not telling us the make and model, it is wired completely incorrectly.

[Tracy D'arth]

I am still not understanding. The inverter has a 240v AC output not input .  No, I'm confused and flustered, not at my best today.

[WotEver]

5 minutes ago, nicknorman said:

you are making it hard by not telling us the make and model, it is wired completely incorrectly.

Correct, and, er, correct. 

[Robbie G]

Sorry not on the boat, Will try and locate a  name and model number, Just a orange box to me , Thanks for all your kind replies, Looks like it’s more complicated than I first thought. Oh well onwards and upwards 

[GUMPY]

Sounds to me that when he tries to use it in inverter mode the input is still connected to the ringmain.

Hence the output of the combi  is supplying the input of the combi.

Not a recipe for success.

Does it work OK if the 13amp input is unplugged? I believe it does from re reading the OP.

 

 

ETA

Having read through again, when run in inverter mode the inverter should have a N-E bond which will cause an RCD on the input  to trip even if the whole thing is correctly wired, which is what was said in post #7

Edited August 20, 2020 by Loddon

[Robbie G]

Yes it seems to be fine when unplugged, Just when plugged in even with the socket switch off , 

[Alan de Enfield]

5 minutes ago, Robbie G said:

Yes it seems to be fine when unplugged, Just when plugged in even with the socket switch off , 

Who installed it ?

[Jen-in-Wellies]

Deleted , 'cause it was dumb.

Jen

Edited August 20, 2020 by Jen-in-Wellies