Inverter derating with temperature (solis)

tails_naf · 24-04-2021 7:03am #1

I am monitoring my inverter temperature and have seen that over the last few days its gotten up to 56C. From reading online, it seems that all inverters will derate their power output if they get too hot. Solis seem to suggest if the ambient exceeds 45c it will derate and shutdown at 60c. It appears the temperature it actually reports is an internal one and can run to 75c (according to the app, but it's not 100% clear).

My inverter is in the attic, so it will get toasty, though I'd be surprised if ambient exceeded 45c. So can anyone answer:

1. How can I tell in the app if the inverter is derating?
2. At what temp should I be getting worried?
3. I can Divert some airflow to pass over/by the inverter, as I have some domestic air exhaust (MHRV) nearby. Is this a good idea? It should help normalise the temp a little.

unkel · 24-04-2021 9:21am

tails_naf wrote: »

3. I can Divert some airflow to pass over/by the inverter, as I have some domestic air exhaust (MHRV) nearby. Is this a good idea? It should help normalise the temp a little.

Does your inverter have active cooling (a fan)? Most don't, so they rely solely on their heatsink for heat dissipation. You say your attic can get hot, so I'd say there is very little natural air flow in there? Creating a little of your own with the MHRV exhaust might be a good idea so. See if it makes any difference

lordgoat · 27-04-2021 6:44pm

Would be interested in this as well. I will hopefully be getting an install very soon. Inverter going into an attic under a tile roof. Gets insanely warm over the summer.

SD_DRACULA · 27-04-2021 6:58pm

Reads worryingly as Solis inverter goes in tomorrow...

mp3guy · 28-04-2021 12:08pm

Non-temperature controlled attics are really not an ideal place for solar equipment; unfortunately this is where most of it ends up. They get hot in the Summer and hence people run into inverter throttling as they overheat (and I suspect it might also bother any batteries up there too). And in Winter they can get very cold, so cold that batteries even shutdown.

SD_DRACULA · 28-04-2021 12:34pm

I'd say it would be a good idea to add a wifi temp/humidity sensor close to the inverter and monitor the ambient temp also.

phester28 · 28-04-2021 2:35pm

My Solis inverter is attic located. 1.5 / 0.9 east west split. 2.5Kwp

Last week it hit 41 deg C when outputting about 1200watts.

Does anyone know. This is my first autumn with panels. Seem to be hitting the 800 irradiance per square meter figures in good sunshine.

That is about 7A per string in direct sunlight. I have ameri solar 300w panels so the 800

1. What current are people seeing on their strings at this time of year.
2. If the inverter is in the attic what max temp did you see.

From last year I had no issue with the inverter clipping. I think I saw 45DegC max.

irishchris · 28-04-2021 11:13pm

phester28 wrote: »

My Solis inverter is attic located. 1.5 / 0.9 east west split. 2.5Kwp

Last week it hit 41 deg C when outputting about 1200watts.

Does anyone know. This is my first autumn with panels. Seem to be hitting the 800 irradiance per square meter figures in good sunshine.

That is about 7A per string in direct sunlight. I have ameri solar 300w panels so the 800

1. What current are people seeing on their strings at this time of year.
2. If the inverter is in the attic what max temp did you see.

From last year I had no issue with the inverter clipping. I think I saw 45DegC max.

My goodwe inverter has been hitting 70+C the last two weeks. In narrow void area near attic

lordgoat · 29-04-2021 4:27pm

My plan on this is if I notice a drop of output to install a gable fan above the inverter. Set it to a temp controlled switch so at least if it is needed it will be power by solar at least

phester28 · 01-05-2021 9:22am

Ok I see your getting 8.7A on your string. What angle are your panels at as I am only seeing 7A on my 300W (around the 800 irradiance figures) That inverter is working very hard in that hot temp. I would not like anything over 60-65 deg in my attic (semiconductor life time) and capacitor temperature will affect life / longevity of the inverter

irishchris · 03-05-2021 12:59am

phester28 wrote: »

Ok I see your getting 8.7A on your string. What angle are your panels at as I am only seeing 7A on my 300W (around the 800 irradiance figures) That inverter is working very hard in that hot temp. I would not like anything over 60-65 deg in my attic (semiconductor life time) and capacitor temperature will affect life / longevity of the inverter

On 45 degree pitched roof.
On a ten year replace free if fails contract so that part worries me less. The fire risk is what scares me a little when I see the temps teaching 70+ consistently

daheff · 02-09-2024 7:02pm

Got an inverter installed in a small utility room. Was not aware of heat issues from these. Is it suitable to put a cabinet around it?

graememk · 02-09-2024 7:54pm

Inverters need free space around them to ventilate, don't build a cabinet around it.

daheff · 02-09-2024 8:00pm

IMG_20240902_195825_HDR.jpg

Electrician told me sticking a cabinet around this would be fine. Starting to get worried about this install..

graememk · 02-09-2024 8:38pm

I wouldn't be putting an inverter in a cabinet (cupboard?) anyway,

They do get warm when working, they should have some free air to allow the heatsink to cool it. By enclosing it you would be suffocating it.

daheff · 02-09-2024 8:44pm

Not even to keep it away from people touching it? I didn't realise these things get so hot.

I was more just thinking of a side on the left a door in front. Top/bottom open.

Also there's a gas boiler about 700mm to the left of the inverter. Presumably that's ok?

I do realise these are questions I possibly should have asked prior to install. I assumed solar company knew what they were doing.

graememk · 02-09-2024 8:54pm

https://www.boards.ie/discussion/comment/122575955#Comment_122575955

Manual looks for 300mm all around the inverter, they don't get hot hot (not a burn risk, but they do get warm, a bit like a radiator)

Gas boiler is fine no issues with that beside it.

The install is neat, everything that can be rearranged entry is rear entry. Very little if anything is exposed.

I'd welcome anyone else's opinion on this.

daheff · 02-09-2024 8:55pm

Thanks. You give me a lot more reassurance on this.

Only about 150mm clearance on the right hand side though.

Inverter derating with temperature (solis)

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