Inverter in loft or cellar?

[BillyH]

Where would be the best place to mount the inverter? In the loft or in the cellar.The dc run would be best part of 25mts away from the array if mounted in the cellar.The consumer unit is also in the cellar.The array consists of 10-250w panels.

 

[Chop]

I like to keep the DC run about 15m max and the AC around 30m max. So id say loft but you can always change the size of the cable to accommodate voltage drops etc

 

[SolarCity]

Upgrade the size of the DC cable and stick it in the cellar. Anything but loft space.

 

[Donavan Bangs]

what's wrong with the loft?

 

[SolarCity]

Lofts can get very warm and dusty - two things that inverters do not like.

Most inverters are installed in loft spaces but I don't think it's a good idea if you can help it - sometimes you can't.

 

[Earthstore]

But then you bring up to 500-600v DC into the house, with the only protection being double insulation, as you are aware a belt from that could be lethal,
Also it is not dusty in the loft, the only problem is temperature in summer.
So which would I prefer, maybe a change of inverter in 10 years, or death because I hit the DC cable with a nail??
Hmmm tough one that!

 

[SolarCity]

It's not just a case of changing the inverter in ten years, you will also get a yield drop as the inverter efficiency drops as it gets hotter.

We make sure our runs are carefully thought out so that the risk of a nail being fired into it is virtually zero. Also, you have to remember that you would actually have to fire a nail into each seperate DC cable and then get hold of each nail independently to actually get a shock. In this regard, it is actually safer than running AC.

 

[Earthstore]

BiggsSolar, I would never dispute your workmanship, my point is that if High voltage DC is not run inside the house at all, then you have zero risk.
Ac, as well as being well protected, in this situation would also be lower voltage.
I accept that on very hot days, the inverter may lose a little efficiency, but surly what all the regs are about is potential risk?
Should you bring a frame earth into the house? The real answer is no, why, because you are bringing a potential into the equiptmental zone, would the same not apply to high voltage DC?

 

[powervan]

lads its all personal choices!!! i say DEPENDS on the JOB! every hse is diff! WHAT i would say is after installing all my invertas in the lofts and suppling sma sunnybeam monitors its my prefferd methord!! untill the madness came and u couldnt get monitors !!so i installed inverta in a garage at eye level!! wow EVERYTHING TO HAND! see what invertas doing!! much better install!! but it was my DADS oh yeh dont get into the EARTHING THING!!!!!!!!!!!!!!!!!

 

[mydigitalhome]

Dont understand why so many people have a problem with invertors in the roof, my preference in most cases - short DC runs which can easily be protected. Sadly I have seen installations with long DC cables unprotected just clipped ready for suitcases and whatever to be thrown onto them with no added protection going down into cupboards and the like with even less ventilation. Or DC cables clipped to the outside wall once again with no protection - Just dont get it accidents waiting to happen. Heat is not a big problem as on the continent they are often installed onto outside wall in full sun with no problems at all working for years happily!

 

[SolarCity]

Heat is not a big problem as on the continent they are often installed onto outside wall in full sun with no problems at all working for years happily!

From what I gather, installing the inverters in direct sun is just about the worst possible place for them.

 

[SolarCity]

I've spoken to a few people from the continent about this issue and they cannot understand the Brits' obsession with putting inverters in lofts. Ask SMA what they think about it if you don't believe me.

It is personal choice, but I think it is far better to spend a bit more time plotting a safe cable run and upgrading the size of the cables.

I often find that the best method is to install an external conduit down the side of the house (assuming aesthetics aren't a problem). This avoids any potential risks.

 

[mydigitalhome]

Part of the reason concerning lofts is that in Spain and Italy they dont normally build their roofs out of wood trusses they use concrete beams with a pot roof infil and then cement their tiles direcly onto that base. So access is is either restricted into those voids or in most cases no access at all. They simply have difficulty understanding the concept of using roof space in the same way we use final ring circuits they dont they only use radials. UK electricians dont generally understand the concept. Its what you get used to. I do agree with BiggSolar that a well designed protected cable run on the outsde of the building to a suitable housing for the invertor is an ideal scenario.

 

[mancshawn]

what do you guys think about installing an inverter on the outside of a house? DC cable in conduit, inverter in a electrical box?? i know SMAs can be installed outside??

 

[moggy1968]

As long as the inverter (and everything else) is IP rated it's fine. theft is the only possible issue but even that can be mitigated. No need to put the inverter in a box, and it would need to be a very big box to maintain airflow.