Inverter fans running much more often

[JBennettBus]

I have a 3-year-old PowerTech-On PS1003 2000W/4000W 12/120V inverter. For the first year or so, the fans almost never came on, even when it was between 90 and 100F (32 to 38C) in the bus and I was drawing a few hundred watts from the inverter. For about a year now, the fans have been kicking in even when it's as low as 85F (29C) in the bus and I'm drawing no power from it at all.

I have a huge problem with dust and cat fur, so I figured the inverter must be riddled with the stuff. But when I opened it, there was almost no dust at all. I cleaned out what little I could find, but there was no change in the fan cycle.

Since this is my first inverter, I don't know if this is normal aging behavior, or if I'm looking at an imminent failure. Is 3 years a typical lifespan for a cheap-ish inverter? Are there any heat sink/thermal paste type upgrades I can do like you would with a computer that's started running warm? Time to replace?

System
6 100W HQST solar panels
Epever Tracer 4210AN SCC
New Li Time 12V 300AH battery
The noisy inverter

 

[Bud Martin]

Do you have good clear pictures of the inside of the inverter so we may see something that is right?
The temperature sensor for the fan is usually mounted on the heatsink, so if the power devices mounted to the heatsink do not have good thermal conduction to the heatsink then the heatsink will not get hot enough to trigger the fan to come on and the power device themselves will get too hot due to poor thermal transfer to the heatsink.

 

[JBennettBus]

No pictures at the moment, but I can probably get some in a day or two. But I'm a little confused. If there's some kind of thermal gap problem like you're describing (power MOSFETS not thermally coupled to the heatsink) then the fans would not be coming on when they should, correct? The problem is the fans are coming on too often, or at least way more often than they used to.

I'll try to get some pictures soon. Until then, thanks for your help!

 

[Bud Martin]

No pictures at the moment, but I can probably get some in a day or two. But I'm a little confused. If there's some kind of thermal gap problem like you're describing (power MOSFETS not thermally coupled to the heatsink) then the fans would not be coming on when they should, correct? The problem is the fans are coming on too often, or at least way more often than they used to.

I'll try to get some pictures soon. Until then, thanks for your help!

That is correct, that is why i want to see the pictures and locate that thermal sensor and try applying some cooling or heating to see when the fan will come on, it can be due to senor issue.

 

[JBennettBus]

That is correct, that is why i want to see the pictures and locate that thermal sensor and try applying some cooling or heating to see when the fan will come on, it can be due to senor issue.

Ah, I got it now. Getting clear photos won't be a problem. I have a fairly decent camera/lens combo handy, and I understand what you're looking for. I'll try to get it done tomorrow.