inverter and heatwave

grinch53

Hi all,
am concerned of the temperature in the loft where my SMA inverter is situated( its out of warranty now). Am told by a local that his has "fried" during last heatwave we have just experienced.
I have a fan aimed at the inverter which  is close to the  hatch door which I leave open and  switch on via remote.But this is only blowing hot air at it and hope it does some good.
Anybody doing anything similar or have any effective ideas?

gazapc

What model of inverter do you have? I've just checked a random SMA 3.6 kW inverter I found online and the datasheet says the operating range is -25 to +60 degrees C. Does your loft get above the temperature range shown on the datasheet for your inverter?

Like any electronics, high temperatures will shorten the life. Although you would expect the manufacturer to specify a range which is slightly conservative.

grinch53

It is a sb3600tl-21 model. I havent measured the temperature , have put thermometer in today to check.
The local told me a solar company whos fitting his new one informed him that inverters should be sited in the loft as a last resort,
better sited outside or in garage.

gazapc

A quick Google suggests also a 60 degree limit for that model.

2nd_time_buyer

grinch53 said:

It is a sb3600tl-21 model. I havent measured the temperature , have put thermometer in today to check.
The local told me a solar company whos fitting his new one informed him that inverters should be sited in the loft as a last resort,
better sited outside or in garage.

I am guessing the loft air temperature is still a fair bit below the inverter temperature.  So I think your idea of aiming a fan at it is a reasonable solution. Adding tile vents would also be beneficial to reduce the heat build up.  

gefnew

you could have a look at this and see if you can do this with your model.
Multi-Function Relay and OptiTrac Global Peak - SUNNY BOY / SUNNY TRIPOWER / WINDY BOY - Technical Description (sma.de)

EcoScruples

I was concerned about this also during the last heatwave although my inverter is brand new.
https://forums.moneysavingexpert.com/discussion/6364702/inverter-temperatures-location#latest
I'm less concerned now as I've seen no drop off in performance due to neat and my loft does get warm.

grinch53

Recorded temp in loft aside the inverter reached 105 degrees fahrenheit ( fans been running all the while), so expect true figure higher and suspect the inverter internals will be higher still. So will be continuing with running fan.
As previous posts have suggested will look at either tile vents or the fan module for the inverter going forward.
Thanks all.

oldskoo1

What's the typical amount of throttling an inverter would do in this sort of heat? Shade temp is 32c and direct sun is approaching 50c. 

My 4kW system is running at 3kW currently, smack bang in the midday sun. I assume this is thermal throttling? 

Is this about the amount you'd expect. 

I need to check it when it goes back to 20c, but at 20c it would normally do 3.4-3.6kW 

EcoScruples

That probably isn't your inverter doing the throttling but your losses from your panels due to the heat. They're at their most efficient at 21 degrees so in these high temps they don't put out as much. My 4.3kw panels are managing about 3.2kw in these 30 degree temps.

oldskoo1

EcoScruples said:

That probably isn't your inverter doing the throttling but your losses from your panels due to the heat. They're at their most efficient at 21 degrees so in these high temps they don't put out as much. My 4.3kw panels are managing about 3.2kw in these 30 degree temps.

Thank you, really helpful, glad to hear they are performing normally.