I have an Axpert Max 7.2kW inverter that has been installed for just short of 2 years now.

Over the last few days, I have noted that the operating temperature has increased by roughly 10 degrees - previously, the unit would only reach around 64 degrees Max, but now it has been reaching 74 degrees.

I just had a look at the bottom of the inverter and with a 5kW load and 4kW of Solar production, none of the bottom 3 fans are turning. There is however, still air flow through the unit (I assume there are other fans on the top).

Any idea what would cause this? The unit isn't giving any error codes stating that fans aren't working.

@Coulomb, have you seen this before?

1 hour ago, Schnavel said:

I have an Axpert Max 7.2kW inverter that has been installed for just short of 2 years now.

Over the last few days, I have noted that the operating temperature has increased by roughly 10 degrees - previously, the unit would only reach around 64 degrees Max, but now it has been reaching 74 degrees.

I just had a look at the bottom of the inverter and with a 5kW load and 4kW of Solar production, none of the bottom 3 fans are turning. There is however, still air flow through the unit (I assume there are other fans on the top).

Any idea what would cause this? The unit isn't giving any error codes stating that fans aren't working.

@Coulomb, have you seen this before?

No there is no additional fans. One fan on the bottom left for the dual MPPT, and two fans on right for the inverter heatsinks. 

If there is airflow, you maybe not hraring them? 

Make sure the top filters on the side are also clean. 

Opened the bottom cover up to have a closer look. 2 of the 3 fans were running, but the one seemed to be jammed. After rotating it slightly, it started running again. I'm assuming that this means the fan is likely on it's last legs, especially considering the inverter didn't give any warning.

@BritishRacingGreen, I see there is some discussion on the forum about changing the direction of the fans. Is it easy to do? What do you do for filters, as the air would then blow out the top where the filters are. 

Also, assuming that the fan is on the way out, any idea on replacement fans? Worth getting an upgrade such as Noctua?

3 minutes ago, Schnavel said:

Opened the bottom cover up to have a closer look. 2 of the 3 fans were running, but the one seemed to be jammed. After rotating it slightly, it started running again. I'm assuming that this means the fan is likely on it's last legs, especially considering the inverter didn't give any warning.

@BritishRacingGreen, I see there is some discussion on the forum about changing the direction of the fans. Is it easy to do? What do you do for filters, as the air would then blow out the top where the filters are. 

Also, assuming that the fan is on the way out, any idea on replacement fans? Worth getting an upgrade such as Noctua?

@Schnavelfirsly, good on you for keeping tabs on your machine's operating temperature. It paid off, cause you detected a failed fan.

I know of the fan direction issue but never gave thought to drill down on it. But seeing that i am also now a proud owner of a refurbished MAX 7.2, I am going to look into it. 

What is your fans doing, pushing air up, or sucking it down? 

By the way the two leftmost fans are super important cause the leftmost one cools the mppts, while the middel one cools the IGBTs.

I am prepared to use my machine for testing any fan mod. 

 

 

I use ICC to monitor my setup, so it's easy to detect any changes over time. 

My fans are presently blowing in the standard direction - downwards. The air is sucked in from the top, through the filters and then out the bottom of the unit. This doesn't really make sense to me as I think it would be better to suck in cooler air at the bottom and exhaust the hot air out of the top of the unit.

3 minutes ago, Schnavel said:

I use ICC to monitor my setup, so it's easy to detect any changes over time. 

My fans are presently blowing in the standard direction - downwards. The air is sucked in from the top, through the filters and then out the bottom of the unit. This doesn't really make sense to me as I think it would be better to suck in cooler air at the bottom and exhaust the hot air out of the top of the unit.

Yeah i thought about that well. Makes perfect sense. But we will probably need to practice  a foam filter on the bottom somewhere. 

Oh, when i decommisioned my 5kw MKS3  last week, I opened it up and the amount of dust i displaced is nobodies business. I used an air compressor. The MKS3 is only 18 months old, BUT i stay in Gauteng, too much dust.  Dust is bad for the machine. 

 

On 2023/01/15 at 1:38 AM, Schnavel said:

I see there is some discussion on the forum about changing the direction of the fans.

That was back in the days of 5 kVA machines, with no air filters at all.

Obviously, blowing air upwards helps rather than hinders natural convection. It's ironic that at idle, the fans approximately cancel natural convection!  My fans have been doing that for years now. I don't have a huge problem with dust, as the two inverters are housed in a large metal box with holes that are just 50mm off a brick wall.

So really the problem of what to do with larger models and filters installed at the top is unsolved.

I'm surprised that the larger model didn't detect a fan problem. But that may mean it's easier to replace them with quieter, better quality fans. A colleague had a problem where Noctuas were just different enough to trigger a false fan locked warning every now and then. The customer didn't like this, as it could mask other, more important warnings like low battery. So on that job, we ended up replacing the original fans.

Good luck. It would be great to have a definitive answer for fans in the more recent models.

Hmmmm, not what I was hoping to hear!

Will have to keep an eye on the unit and the fans. I blew it out over the weekend and while a fair amount of dust did come out, it wasn't excessive. I also gave the filters a good clean. It seems to have a helped a little, as the maximum temperature was around 4 degrees lower today - still high though...

On 2023/01/16 at 4:15 PM, Schnavel said:

Hmmmm, not what I was hoping to hear!

Will have to keep an eye on the unit and the fans. I blew it out over the weekend and while a fair amount of dust did come out, it wasn't excessive. I also gave the filters a good clean. It seems to have a helped a little, as the maximum temperature was around 4 degrees lower today - still high though...

Did you manage to make any progress on this matter? I'm also facing high temperatures and that makes me a little nervous.

I didn't make any changes to the setup on the inverter, but I'm still keeping an eye on the fans to ensure that they are all spinning freely.

In terms of the high temperatures, I ended up installing a vent fan in the roof above the inverter. In winter I don't have any problems as the ambient temperature is low. In the summer months, my garage gets rather warm. The vent fan helps to keep air flowing through the garage and helps to expel a lot of the hot air from the inverter. I noticed a roughly 10 degree difference in temperature with the extraction fan running.

28 minutes ago, Schnavel said:

ended up installing a vent fan in the roof above the inverter.

That's pretty much what I did too, added a fan through the wall at the left hand side of the inverter, next to where the air filter is.

However I get the feeling this is not entirely effective as the fans on the inverter will suck air from above and therefore push the hot air towards the bottom.

I wonder if anyone has come up with a way to reverse the fan direction on this model too (as it was done on the 5kVa).