Off grid inverter issue

[Feenster]

Is nu

your inverter has N-E link witch is controlled i.e. with a supply to grid connection in your inverter N-E link will be open and closed in island mode i.e. as UPS

Yes, MSJ, that is the case. But I am completely off grid and therefore that only occurs with the generator.

 

[Feenster]

I have one earth rod to which all connectiions are made including the battery neg and the CU earth. I have found that Outback have a genuine knowledge about their product and provide full technical back up. I read their manuals and any doubts I have always asked for and got answers from their technical dept. My system has grown and altered over the years but I have not suffered from any of the tripping issues you have with your new kit. I'd take up the issue with the manufacturer.

So, offgridAndy, do you consider your system as TT or other? I am struggling to get anything online about the earthing arrangement for a completely offgrid system with no mains electricity at all.
I have an earth wire running from my fuse board down to the earth rod.
I have an earth wire joining onto this earth wire coming from the earth attachment on the outside of the generator.
I have an earth wire joining onto the earth from the fuse board from the wind turbine charge controller.

Apart from the battery negative are there any other connections that you have made to the earth rod?
The manufacturers usually give general answers, not specific to my situation.

 

[Feenster]

my bad, your RCD is controlling the whole supply - I've had afew things on my mind lately and didn't study your diagram properly.

Thanks for the clarification.
However, does it still apply that it would be better to put a RCBO on each ring circuit rather than 1 RCD 'looking after' 6 or 7 MCB's controlled ring circuits?
The radial circuits for the lights are only MCB protected - they should probably be RCD protected also?
(However, an interesting thing happened recently. The RCD 'tripped' when it was wet and windy. After much trial and error I found the problem to be an outdoor light fitting that water was getting into. The RCD is only on the ring circuits and shouldn't have anything to do with the lights and yet it 'tripped'.)

 

[Feenster]

this is an interesting read,

https://electrical.theiet.org/wiring-matters/years/2020/82-september-2020/mythbusters-6/

I had a quick look at it, thanks. I will go through it in more detail when I get the chance.

 

[binky]

Thanks for the clarification.
However, does it still apply that it would be better to put a RCBO on each ring circuit rather than 1 RCD 'looking after' 6 or 7 MCB's controlled ring circuits?
The radial circuits for the lights are only MCB protected - they should probably be RCD protected also?
(However, an interesting thing happened recently. The RCD 'tripped' when it was wet and windy. After much trial and error I found the problem to be an outdoor light fitting that water was getting into. The RCD is only on the ring circuits and shouldn't have anything to do with the lights and yet it 'tripped'.)

I would RCBO everything, at the moment you get 30mA of 'leakage' to earth before the RCD trips, with RCBOs you get 30mA per circuit, which is a lot more reliable and what I have in my own house. Modern appliances have lots of circuit boards and sensitive electronics in them, to protect these, they usually throw a bit of leccy down the earth as part of 'smoothing circuits', so it doesn't take long to get upto 30mA with a trivial fault, like an appliance just getting old.

 

[Feenster]

I would RCBO everything

Sorry Binky, only saw the post now.
With the short days I haven't bothered trying to do anything with inverters, etc.
Can you give me some idea of the type of RCBOs I should be looking at - 1 pole, 2 poles?
(I guess Type B tripping curve as per MCB and type A as per RCD)
Thanks.

 

[binky]

Sorry Binky, only saw the post now.
With the short days I haven't bothered trying to do anything with inverters, etc.
Can you give me some idea of the type of RCBOs I should be looking at - 1 pole, 2 poles?
(I guess Type B tripping curve as per MCB and type A as per RCD)
Thanks.

Should be twin pole for full compliance, don't worry too much about type, it's not been a problem for decades