Solar Pannels and Changing Sockets

[Exinferis]

Hi all.

Apologies if this has been asked a million times before, but a search didn't get me any results.

I need to change a couple of sockets and replace the pull cord switch to my electric shower. Usually I'd just turn off the main breaker as the wiring in this house isn't the best. I've searched online to see if I need to turn the solar panels off and it seems not. But I read a comment elsewhere that said if you switch the main breaker off on the CU you have to turn the panels off too. Is that right?

There's no battery for the panels.

Sorry if this sounds like a stupid question, but I'd rather be safe than sorry!

Cheers,
Ex

 

[Why Not Indeed]

If in doubt, isolate. Your PV inverter should not energise its output if it does not detect mains voltage, so you could get away with not isolating it if you switched the main breaker off. But it's not going to cost you anything to do it thoroughly, so don't take the chance.

 

[ericmark]

My supply from the main consumer unit is isolated by turning off the isolator, and can be turned off by turning off a RCBO, only one of my RCBOs isolated the supply (turns off both lives, line and neutral) but in the main I will take a chance and just turn off the line.

But I have three outlets which turning off the consumer unit will not turn them off, two double RCD sockets used to power the fridge and freezers, and one FCU which powers the central heating, and to turn these off I have found very hard, it seems the order the switches/isolators are turned off matters, and when I need to work on these circuits, I unplug it from the inverter, as I don't trust the isolation procedure.

It is very much dependent on how the solar panels were wired in. In theory @Why Not Indeed is correct, loss of supply, should cause the solar panels to auto shut down, in most cases, they are designed so if the mains supply voltage goes out of limits they close down, so you can't get an island of solar panels supporting each other, and it is safe to work on the supply.

But the whole point of my solar panels and battery, is that in a power cut my freezers and central heating continues to work. So there are exceptions.

 

[Exinferis]

If in doubt, isolate. Your PV inverter should not energise its output if it does not detect mains voltage, so you could get away with not isolating it if you switched the main breaker off. But it's not going to cost you anything to do it thoroughly, so don't take the chance.

Thank you, I appreciate the response. I'll do that.

 

[Exinferis]

My supply from the main consumer unit is isolated by turning off the isolator, and can be turned off by turning off a RCBO, only one of my RCBOs isolated the supply (turns off both lives, line and neutral) but in the main I will take a chance and just turn off the line.

But I have three outlets which turning off the consumer unit will not turn them off, two double RCD sockets used to power the fridge and freezers, and one FCU which powers the central heating, and to turn these off I have found very hard, it seems the order the switches/isolators are turned off matters, and when I need to work on these circuits, I unplug it from the inverter, as I don't trust the isolation procedure.

It is very much dependent on how the solar panels were wired in. In theory @Why Not Indeed is correct, loss of supply, should cause the solar panels to auto shut down, in most cases, they are designed so if the mains supply voltage goes out of limits they close down, so you can't get an island of solar panels supporting each other, and it is safe to work on the supply.

But the whole point of my solar panels and battery, is that in a power cut my freezers and central heating continues to work. So there are exceptions.

Ah, I see, thanks. We didn't really get much paperwork for this tbh. It was one of the Gov. schemes to upgrade old houses with insulation and panels etc. They basically came, fitted it, had me install the app and went, "Bye!". Up until now I had no need to do any electrical work.

 

[ericmark]

I am reasonable sure in your case if you turn off the MCB/RCBO in the consumer unit you will be safe.

The fitting of solar panels without a battery is a bit hit-and-miss. There is no way I can look at the weather, and work out if I can run the tumble drier (which takes 2.5 hours) direct from solar without the solar being stored. Other than something like iboost+ which has a monitor

on the DNO tails so it only uses any power over the set export offset to heat water, to use solar, we need some storage.
I watch the purple line on this display it shows how charge the battery is, and today I have zero export, but the battery has been nearly fully charged by solar,

well at least to 94%, as to if it will last until 00:30 tomorrow when the off-peak starts, depends on our evening meal. I get paid for export in summer, now dropped to 12p/kWh from Sunday, and with 6 kW of panels, a 5 kW inverter, and 6.4 kWh of battery, we still pay for electric, but with off-peak supply, we are looking at average over last 10 months of £18 a month. Before solar was paying around £120 a month, but prices have changed over that time, so all is approximate.

The main saving is not the panels, it is the battery, every day I am paying 8.5p/kWh for first 5 kWh of electric used, my avarage is around 12 kWh, with some of that during off-peak, it means I need around 5 kWh of solar, to not pay for any electric at peak rate.

I have considered a third battery, but at £1000+ each for a 3.2 kWh battery with a life over 10 years, but likely not much over 10 years, it is on the edge if it will pay for its self. And with balcony solar looking like it will get approval, I am hanging on and watching developements.

Once we have the second MPAN number, who will know what is exported using balcony solar, and what is exported under the agreed solar panel size output wise? The swapping of the inverter should be notified, but who will know? I think as it stands a third battery rather than balcony solar will be better. But since balcony solar is DIY, and third battery I would need to pay for the installation, not so sure.