Inverter Location - Outside - Temperature Extremes

**Mike90250** · 12-17-2019, 11:38 PM

The larger the thermal excursions are, the faster the mechanical connections and solder joints stress and crack. All I really know about this is from experience with spacecraft, and the weeks we spend doing thermal analysis, and using exotic materials that have like TCE's so the stress is reduced. Even then with film resistors and chip capacitors, you have stresses between the layers of components. Eventually, something fails.

https://www.murata.com/en-global/sup.../mlcc/mnt/0007

Analysis of thermal failure of electronic components - ppt video online download

https://slideplayer.com/slide/4213558/

25. Analysis of thermal stresses and strain in electronic components Substantial efforts made in the fabrication methods, mounting methods, and cooling techniques of the electronic devices to reduce the hot spot temperatures below 100 °C. This has produced a significant improvement in the reliability and effective operating life of the electronic equipment. Experience has shown that most of these failures are produced by a mismatch in the thermal coefficients of expansion (TCE) of the different types of materials typically used in electronic assemblies. The mismatch often generates high forces and stresses, which produce fractures and cracks in the electronic components and assemblies.

**J.P.M.** · 12-18-2019, 11:47 AM

I'd start by looking at what the mfg. of the equipment writes in the product manuals and product literature with respect to environmental operating conditions and limitations.

As a general comment, the more variation in environmental conditions the equipment sees and the greater the speed of those variations, the probability that something will fail sooner will increase.

If it was me, I'd get the inverters out of the weather and into a more controlled environment. Inverters are a bit like house pets. They get less likeable and less reliable the more they're left outside.

**peakbagger** · 12-18-2019, 06:18 PM

Shade really makes a big difference. Not sure if the proposed inverters have active or passive cooling but critters just love to make nests in the cooling channels. I saw one install once where they enclosed the entire inverter in a screened in box as otherwise they had to clean the filters every few weeks.

**Flying Scot** · 12-19-2019, 01:46 AM

Folks - thx for your advice - all makes sense and pretty much reinforces my concerns (I was blindly hoping that folks would come back with 'no problem, don't worry, done this lots of times' etc

) FYI manufacturer's operating ambient temp range is between -40 & +55 deg C.

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As I said I'll ensure to fit a sun shade. The units have 10 year warranty and I have a back-up unit to give some flexibility in the event of a failure. I'll leave the install as-is for the moment. If I start having problems I'll look to fit a conditioned enclosure and update this thread accordingly. My decision to leave the install alone for the moment is largely because I suspect I caused the failure of the original unit by enclosing it and inadvertently causing the ambient temperature to increase.

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Attached Files

**emartin00** · 12-19-2019, 09:35 AM

You should be fine. These inverters are made to be installed outside, and there are probably tens if not hundreds of thousands of them installed outside.
Heat is going to be harder on them than cold, and you live in a relatively cool climate.

**Mike90250** · 12-19-2019, 10:58 AM

A simple awning to provide shade from the sun, would be the most bang for the buck.

To get fancy, throw a $20, 20" window box fan near them with a timer for 11am - 4pm to move air around

Inverter Location - Outside - Temperature Extremes

Inverter Location - Outside - Temperature Extremes

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