Tails from inverter to consumer unit

[RCZ]

…can the tails going into the consumer unit from the inverter, go straight into the main switch rather than a MCB…I can’t see it makes any difference…thanks

 

[Murdochcat]

Absolutely not

 

[RCZ]

Can you explain…

 

[bernardgreen]

can the tails going into the consumer unit from the inverter,

The design of the installation has to ensure that the output from the invertor cannot under any circumstances reach the incoming electrical supply.

One reason for this is to prevent engineers who have turned OFF the local power supply from receiving an electric shock from the invertor that has become connected to the local network.

 

[RCZ]

Thanks Bernard….I understand what you’re saying but I don’t understand the logic….wherever you connect an inverter to a consumer unit in a solar installation, it’s going to make contact with the incoming mains supply. You don’t disconnect the mains supply when the solar power is suppling energy to the consumer unit and your house?! I’m obviously missing something…

 

[bernardgreen]

Google "solar changeover switch"

 

[martygturner]

Err inverters shut down when the grid feed is not present . If you have a grid tie then then inverter is constantly exporting solar when the demand is less than the supply, which the op does as his solar is connected to the consumer unit.

There seems to be a massive misunderstanding between a system with island mode - ie powers the house when the grid is out and standard solar that just cuts the kw drawn from the grid.

The fuse is there as it protects the cable going to / from the inverter like any other cable in your house.

 

[Why Not Indeed]

Google "solar changeover switch"

Some context here: https://www.diynot.com/diy/threads/...nnection-to-consumer-unit.500279/post-5874317

 

[SpecialK]

How will you protect the cables from the main switch to inverter? The only fuse would be the main incoming DNO fuse at maybe 100A?

Much easier to use an MCB. It cant be on a shared RCD though.

 

[ericmark]

What inverter, what design of consumer unit etc. I not France so may not be the same as UK, but the question has been answered even though in the initial question there was not reference to the supply being from any other source,

Thanks Bernard….I understand what you’re saying but I don’t understand the logic….wherever you connect an inverter to a consumer unit in a solar installation, it’s going to make contact with the incoming mains supply. You don’t disconnect the mains supply when the solar power is suppling energy to the consumer unit and your house?! I’m obviously missing something…

This says you do intend to interconnect two supplies, however I note on my inverter it needs setting for the country, and you can't expect an answer on to British forum to automatically apply to France.

There are a number of things required.
1) Automatic disconnection of solar panels from the DNO supply should the DNO supply fail.
2) If the DNO supply fails then earth and neutral require bonding, but also they must not be bonded if the supply is good.
3) There needs to be an earth which does not rely on the DNO supply.
How this is done varies, and my inverter has a load of DIP switches to set it for the country being used in.

Since my inverter can only supply 5 kW the UPS is a different supply to the rest of the house, so with loss of DNO supply most of the house will lose power, so the neutral to earth bonding is only for the UPS supply, and the UPS supply in my case does not connect to the consumer unit, I have just one FCU and two double sockets from the UPS.

There is also the problem with uni-directional and bi-directional automatic disconnection devices, which would stop being able to connect the solar inverter to a standard consumer unit, again it will depend on the design of parts which are used in the consumer unit.

General statements without some more information are pointless.

The design of the installation has to ensure that the output from the invertor cannot under any circumstances reach the incoming electrical supply.

I know what you are trying to say, but the whole idea of exporting solar power could not happen if that were true, no one has said what type of inverter, there is simply not enough information, and even if there was more information, I know France has a different way of supplying private homes, with a lot more split phase than found here in the UK, and also often 16 amp supplies where in the UK rare for it to be under 60 amp.

It was 1980 when I worked on old French supplies, so some what dated, but I know enough not to expect French rules to be same as UK, often their MCB are two pole for example.

If there are people on here who do know the French system then OK lets hear from them, but I would not try to tell some one how to do things in another country except in very general terms, and although I have worked abroad, it was 30 years ago, so things may have changed.