Change over switch grid/PV

graememk

https://www.boards.ie/discussion/comment/123094615#Comment_123094615

You do need a battery to go off grid, and the battery could limit your power, not the inverter. but its all a "it depends"

Norrie Rugger Head

https://www.boards.ie/discussion/comment/123094630#Comment_123094630

I have batteries was just thrown by the amount of conflicting comments about it

Paul Kiernan

https://www.boards.ie/discussion/comment/123094289#Comment_123094289

What happens if (when?) your load exceeds the inverters rated output? E.g. someone turns on the kettle or a cloud blocks out the sun?

con747

https://www.boards.ie/discussion/comment/123094824#Comment_123094824

I only put on what I know it can handle, if someone puts on a kettle when i'm near the limit of the inverter it shuts off power and you have to wait until the fault registered clears (about 3-5 minutes) I think on my Solis and then you can use it again in my experience anyway.

Paul Kiernan

https://www.boards.ie/discussion/comment/123094873#Comment_123094873

So I'm assuming the max load you can draw is whatever the solar is producing at any point in time plus whatever the inverter battery output is rated at (eg 3kw). It then trips automatically if you exceed this?

con747

https://www.boards.ie/discussion/comment/123094923#Comment_123094923

On mine I can use just under 5kw safely before it trips. I only use very low powered stuff though, router, cctv, tv, and the likes and a microwave 800w, if I need to boil the kettle I check the load being used first and turn stuff off if need be. It's served me well for 3 years doing that.

nimrod86

Luckily I didn't lose power (yet…) but I'm now very interested in adding a changeover switch to my setup. Has anyone managed to get an electrician out to fit one, and if so what was the cost of doing it? Even better if anyone has recommendations for companies doing them.

con747

https://www.boards.ie/discussion/comment/123095305#Comment_123095305

Mine was done as a cash deal with more panels and optimisers fitted by my original installer so not sure exactly how much just for it. It was cheap enough though, not the mad figures I hear some people getting quoted but it depends on what work needs to be done between inverter and consumer unit. Mine were beside each other so minimal work involved.

SD_DRACULA

The only problem is that most regular sparks haven't got a clue how to wire one in even though it's not exactly rocket science.

The nicest way is to get an extra cable fed from the inverter to the consumer unit and just have the changeover switch there.

The other way which involves no new cables back to the CU is to have a changeover switch beside the inverter and you use this to flip between backup circuit and grid but you have to go to the inverter location to change over (who cares if it only happens once in a blue moon) so you're reusing your existing grid feed.

For either option the earth neutral bonding is required to be done via a contactor or option 2 is to switch only the live feed and then use the ESB's bonding (this means you can only use the backup power when the grid is actually dead not just whenever you feel like it as with the contactor)

If you have a fireman's switch and grid dies it will also cut power to the panels so you're running off battery but no solar.

I bypassed this by adding an extra changeover switch for the fireman switches as well so they can get power from the backup port and continue to operate.

nimrod86

https://www.boards.ie/discussion/comment/123095390#Comment_123095390

Interesting… my consumer unit is in the hall downstairs and recessed into the wall (very tidy looking) so the thought of having a surface mounted box beside it wasn't appealing to me. Putting it beside the attic in the inverter would be neater for me, and it wouldn't be needed often. If switching at the inverter though and sending the backup down the same cable as the AC supply for it then would it not still be backfeeding out of the house?

My understanding for a switch over was that the feed from the meter to the main consumer unit was being switched, therefore totally isolating the meter from the house? eg. Grid and solar into switch over, and one feed back to the main consumer unit? Open to correction on this.

SD_DRACULA

https://www.boards.ie/discussion/comment/123095590#Comment_123095590

So you don't need an external box or anything, if you got 4 slots free in your CU the changeover switch can fit there as it's basically like an mcb.

Shouldn't back feed as it sends the power it needs to the board but you'd probably want to turn off your main breaker to be sure.

I think what you're talking about is to have a sub board beside your main CU where you only power some of your circuits (lights, boiler, fridge) and basically move those over using the changeover switch.

My inverter can power the whole house easily so it's wired to power the whole board, you can do the same of course but just have to be mindful of what you turn on.

nimrod86

https://www.boards.ie/discussion/comment/123095626#Comment_123095626

Yeah, my inverter can supply 5kW so other than the electric shower it should be able to power the rest of the house without much issue. My ideal setup would be to disconnect completely from the grid and supply the whole house from the batteries.

Looks like I'll need to do some googling and try find an electrician willing to do it. I emailed a solar crowd who's vans I've seen in my estate (not the installers of my system) asking for a quote just for this but they said they can't help me.

nimrod86

Just for anyone else who might be interested, Martin from Wizer Energy (based in Cork I believe) posted this in a Solar Facebook group regarding installing a changeover switch. For the few hours a year I lose power the cost wouldn't be worth it for me anyway, though I'm struggling to understand why it's so high when the switchgear and cabling needed couldn't be more than €200. I'll be abandoning plans unless I can find an electrician able to fit one for labour costs with myself supplying the parts.

I'm not affiliated in anyway with Wizer Energy, just thought the information is relevant.

tommythecat

When we got our solar and battery last January I enquired with the (well known) installer and they said they can indeed install a changeover switch. Cost €1,200.

con747

https://www.boards.ie/discussion/comment/123100443#Comment_123100443

I had an extra 4 panels, 4 optimisers and a changeover switch installed in March 23 for €1200 by my original installer so I doubt it's gone up that much now with no vat on installs even though mine was a very easy install for it. I thought Martin from Wizer was competitive but not going by those figures! Before the Reci police jump in I know each install is different and I'm just giving my experience.

irishchris

Changeover switch and battery storage installed couple years back is really paying for itself this week. Power down since Friday and estimated restore on text Tuesday from esb is 9 Feb!!

Cooking, heating and all round use in house once under 5kw is working perfect. Now if only I could have my own broadband as down since along with phone coverage. Yep to Tesco today to use their WiFi to check in on the outside world 😀

JohnySwan

https://www.boards.ie/discussion/comment/123100443#Comment_123100443

Shouldn't really be any more than about 800 quid max.

Depending on the install it's about a day's work to do it right. Quite a bit of rejigging of the DB, earthing arrangements while off grid need work too. Then there's the testing and cert.

Something else to consider is the hassle you bring on yourself when there's large scale power cuts like the last week. The amount of calls/texts/emails asking technical questions regarding the changeover, because in my experience most people don't pay attention when operating procedures are being explained.

Martin actually had a post saying that customers were contacting him, giving out that they didn't have charge in their batteries when the power went out. 🤷‍♂️

Another consideration is the fact that they're inundated with more profitable work, installing panels.

You could always call a local electrician, ask if they have an hourly rate, then explain what you would like to have done. The only issue with that is most regular sparks don't have any experience with inverters.

con747

https://www.boards.ie/discussion/comment/123101293#Comment_123101293

It's not that complicated though, with mine I just flick 2 switches down in the consumer unit and I'm running off the batteries so even homer simpson could manage that!

JohnySwan

https://www.boards.ie/discussion/comment/123101379#Comment_123101379

It isn't complicated, but you still get the hassle. My brother in law always calls me when he has a power cut asking what he needs to do.

You need to remember that there are people out there who can't change a light bulb.

Slutmonkey57b

I have the sigenergy energy gateway which worked nicely but I don't know that I'd trust a random electrician to know what needed doing. All of the solar installers I contacted claimed never to have heard of such a system, that only manual switchover was allowed, and that they couldn't see how it would be done anyway.

I ended up sending YouTube videos to some of them and not so subtly pointed out that some of the companies they were installing for sold the thing, it was in their product catalogue!

As with most things in this country, there's a "bog standard" accepted way of doing things (usually what's least effort) and that's all anyone's interested in.

If automatic switchover is illegal, what happens in an operating room during a power cut? The surgeon saunters down 4 flights of stairs to pull the crank on a generator then clunks a rotary switch to "on"?

John mac

i have a changover switch , worked fine for 3 days until battery ran out .. hooked up a generator to the house , (yes the grid is isolated) battery now half full , problem now is the Sofar wont go into eps mode when i disconnect the power . any suggestions . .. EDIT.. tried again there , and it worked , dont know what i was doing earlier that it wouldnt go into eps . have plenty of juice to keep us going overnight .

Novice Self-Build

Very new to this so hopefully this question makes sense. Had a change over switch installed when house built in 2023. I have not tested it yet but planning on buying a generator. Will a regular 8.125 kVA Output, Dual Voltage (115V / 230V) with Automatic Voltage Regulator be sufficent or do I need to buy a more expesive Inverter generator? and second question, if I connect laptop, leisure battery via a VEVOR Pure Sine Wave Power Inverter 3000W DC12V to AC230V to an oldder 3kv regular generator does this make it safer for sensitive equipment? Thanks.

hanloj1

https://www.boards.ie/discussion/comment/123100443#Comment_123100443

Martin quoted me 1500 for changeover that will allow solar to charge battery too. Inverter/battery 1-2M away from CU, Sofar inverter/ battery. Seems bit high as inverter is so close to CU, I plan on getting more quotes to check.

SD_DRACULA

https://www.boards.ie/discussion/comment/123257117#Comment_123257117

Very high unless he's replacing your whole board as part of the work.

foobar

Hope you don’t mind me hijacking this thread.

I’m planning to install a changeover switch for my solar setup and am considering allowing for a generator as well (which I currently don’t have). Would this significantly increase the complexity and cost of the installation?

Poweller37

hi, and did ya get your grant in the end? With the change over switch?

Poweller37

@JayBee66 did you get your grant approved?