1 minute ago, pilotfish said:

I reckon 70'C is a bit over the top

yes, can't figure that the guys, even if they call themselves 'engineers' don't address the heat problem - maybe they design the stuff near the arctic circle...

maar 'n boer moet maar 'n plan maak

Today was another 70'C day for the inverters, including a generation drop-off which I'm guessing was over-temp related because it coincided with the peak temperature. So I banged in 4 fans in 15min which had a dramatic effect on the temperature reading;

As soon as the fans where switched on the temperature plummeted from 70'C to 51'C

The method that I used was to leave the stock fans in place blowing out the bottom, but added 2x 80mm PC fans to the top vents of each inverter blowing air in. In this way I reckon it is assisting the stock fans, not creating any dead spots, and not fooling around with the warranty.

I am very happy with the result, the job took literally 15min and didn't require opening the case and I can recommend this route to anyone that feels that their Axpert temps are excessive.

 

I have noticed my Axpert which I have inverted the fans on gets hottest when running off Eskom (about 50 degrees). During the day the inverter temperature is in the lower 30s but the solar charge controller's heatsink gets to about 50 degrees. 

On 9/8/2017 at 2:47 PM, plonkster said:

so the idea is clearly to control the fan

@plonkster I thought it was obvious when you read the heading of the article ,  . 

The way I used them was by "inserting" the probe into the heatsink , in my case the cpu , then have a look at the temp output on the pc. Increase the pot until the fan starts ramping up at the desired temp. You will get a equilibrium where the fans efficiency meets your stating temp. I took a bit of fiddling in the beginning but once you got it working it works quite well.  

When I was not using the pc and it was on idle there was almost no fan noise but the moment you started working the temp would go up and so the fan would start up.

36 minutes ago, PaulF007 said:

there was almost no fan noise

my two degrees centigrade worth is; does the inverter's fan noise bother anyone? except if your office happens to be the garage

ok, easy for me to say, being blessed with about 50% hearing loss :-) - but if things get too loud i just silence the hearing aids [so now you know i've got aids...] and sink back into the woolly comfort of quietude

2 hours ago, PaulF007 said:

 I thought it was obvious when you read the heading of the article ,  . 

I just saw something was missing, assumed that it was a comparator circuit (so the fan turns full on and full off), and rushed in like a damn fool. Then noticed the Emitter-follower setup on the output and realised... hang on, this isn't completely wrong... :-)

If it was me though, I'd use an NPN transistor, put the fan on the other side, and flip the pins of the op-amp around so it works the other way round. And add some proper gain-control. Should make it a whole lot less finicky to adjust too.

I don't know why I have this ingrained OCD-like preference for NPN over PNP. Someone must have taught me that. If I google it now, it seems it is based in reality somewhere (better current carrying capability, cheaper to make). Probably the same reason we prefer N-channel FETs over P-channel FETs (cheaper, lower RDS_on, etc).

:-)

Extract from the AEVA forum

Today we fired up the new PIP-5048, working good the fans run all the time unlike the earlier version's 
And they have finally put the fans in the other way round, now they draw the cool air in through the bottom and the heat comes out the top, As it should.

2 hours ago, gabriel said:

my two degrees centigrade worth is; does the inverter's fan noise bother anyone? except if your office happens to be the garage

True I would also not bother with the inverter. As long as the temp is within spec. 

43 minutes ago, Chris Hobson said:

Extract from the AEVA forum

Today we fired up the new PIP-5048, working good the fans run all the time unlike the earlier version's 
And they have finally put the fans in the other way round, now they draw the cool air in through the bottom and the heat comes out the top, As it should.

Nice! And, finnaly

16 minutes ago, SilverNodashi said:

Nice! And, finnaly

common sense won this round!

27 minutes ago, Chris Hobson said:

Today we fired up the new PIP-5048, working good the fans run all the time unlike the earlier version's 
And they have finally put the fans in the other way round, now they draw the cool air in through the bottom and the heat comes out the top, As it should.

I wonder though if this fan direction change didnt come with some additional design changes?

The reason I ask this is because while I was installing the extra fans I noticed that the bottom cover was BLAZING hot (I removed them then to allow free air flow), obviously as a result of the fans blowing the hot air out the bottom.

So now if the fans are reversed then the top mounted heatsink will get the benefit of this blazing hot air - and I am sure that the heatsink mounted components (thyristors and such like wizardry) are not going to be too happy unless additional design changes accommodate this.

The thing for me is that the Axpert MKS5 is a clever piece of kit that must have had some some smart guys involved in the design, I am sure that between them someone must have known that hot air rises and that this would be the natural orientation for the fans - if they decided against this simple principle they must have had a good reason, and I reckon that not putting additional load on the heatsink was IT!

54 minutes ago, pilotfish said:

between them someone must have known that hot air rises

if common sense were common, why do so few have it?

some 'great' engineering 'feats' turned out to be disasters, some great battles were lost due to 'small' mistakes... until otherwise proven i will look at the fan issue as a construction flaw

Interesting. A while ago someone here reviewed one of the smaller blue Phoenix inverters and found it a little underwhelming. I quietly passed the links up my chain of contacts and it actually went all the way to the designer of the hardware. The complains was also that it runs too hot, that the compnents are just flapping in the breeze, and that just adding a few clip-on heatsinks solves the heat problem. The designer said that yes, he knows it runs a little warm, but it is within spec, and if you add heat sinks you add vibration problems, and this thing is designed to go into places that vibrate!

:-)

14 hours ago, plonkster said:

this thing is designed to go into places that vibrate!

like speedboats and f1 and dakar vehicles - the guy is nuts... or wait, what he means is they are exported to earthquake prone zones

EDIT

i should not be so hard on the guy - his home tongue could be mandarin and the word 'vibrate' just mean less than perfect conditions or whatever google translate gave him; so whoever you are we don't want to belittle you, but do allow us our 'humoresque' license

21 hours ago, pilotfish said:

...  the Axpert MKS5 is a clever piece of kit that must have had some some smart guys involved in the design, I am sure that between them someone must have known that hot air rises and that this would be the natural orientation for the fans - if they decided against this simple principle they must have had a good reason, and I reckon that not putting additional load on the heatsink was IT!

Well, per this post about the Pip-5048, arguably the latest version of the Axpert:

http://forums.aeva.asn.au/viewtopic.php?p=65520#p65520 

"And they have finally put the fans in the other way round, now they draw the cool air in through the bottom and the heat comes out the top, As it should." 

I note that the heatsink has the ability to sink heat to the atmosphere, more so than the bottom plate. Also, newer models don't have the heatsink at the top, and the SCC is in the middle between the two main heatsinks.

31 minutes ago, Coulomb said:

Also, newer models don't have the heatsink at the top, and the SCC is in the middle between the two main heatsinks.

So there it is, moving the heatsink off the top allowed them to change the direction of the fan, so for older models I would still recommend adding fans to assist the design airflow rather than reversing the airflow - just a guess on my part, not because I know anything others dont.

17 hours ago, gabriel said:

i should not be so hard on the guy - his home tongue could be mandarin

No, that's the word I paraphrased into, I have no idea what the original was. I meant it in the sense that auto makers talk of NVH (Noise, Vibration, Hardness), it's an actual technical term. That is, these small inverters are made to be mounted to the chassis of a vehicle -- and survive.

ahaaa, didn't know that - would these vehicles then have pvs on the roof

45 minutes ago, gabriel said:

ahaaa, didn't know that - would these vehicles then have pvs on the roof

Emergency vehicles, field service vehicles where you might want to run an electric drill or some equipment, camping and/or leisure vehicles...

Somewhere in the world (I forgot where) they use the Multiplus in their fire engines to assist the electrical boost pumps. If they are somewhere in the sticks without proper water pressure and a limited power supply, they use the Multi's PowerAssist feature to make up the difference.

On 9/11/2017 at 3:12 PM, gabriel said:

like speedboats and f1 and dakar vehicles - the guy is nuts... or wait, what he means is they are exported to earthquake prone zones

EDIT

i should not be so hard on the guy - his home tongue could be mandarin and the word 'vibrate' just mean less than perfect conditions or whatever google translate gave him; so whoever you are we don't want to belittle you, but do allow us our 'humoresque' license

Victron Energy units ( maker of Pheonix) is commonly used in Yachts and RV's  as well as service, catering vans. Vibration is common in these scenarios. 

In fact, recently a Boat powered by Victron inverter and batteries won the race - https://www.victronenergy.com/blog/2017/09/08/solar-boat-racing-clafis-victron-energy-unstoppable/

  I use a 350 VA Pheonix to run my critical loads  ( NAS, Router, switch etc) as the thing consumes less power while inverting than an APC ups which is on standby. it is running nonstop for last 6monthss without any issues at 50 % or more load 

3 hours ago, ghatikar said:

Victron Energy units ( maker of Pheonix) is commonly used in Yachts and RV's  as well as service, catering vans. Vibration is common in these scenarios. 

thank you @ghatikar for providing us with this information!

we will think twice prior to jumping to conclusions in future.... although you must admit we could not resist this issue being used for a bit of fun

On 2017/09/09 at 8:36 PM, pilotfish said:

Today was another 70'C day for the inverters, including a generation drop-off which I'm guessing was over-temp related because it coincided with the peak temperature. So I banged in 4 fans in 15min which had a dramatic effect on the temperature reading;

As soon as the fans where switched on the temperature plummeted from 70'C to 51'C

The method that I used was to leave the stock fans in place blowing out the bottom, but added 2x 80mm PC fans to the top vents of each inverter blowing air in. In this way I reckon it is assisting the stock fans, not creating any dead spots, and not fooling around with the warranty.

I am very happy with the result, the job took literally 15min and didn't require opening the case and I can recommend this route to anyone that feels that their Axpert temps are excessive.

 

Hi there

We also have an axpert inverter that's getting into the 70s so I'm thinking of adding fans. 

Just a quick one, did you note a significant drop in the temperatures over a prolonged period of time? 

The temperature dropping in your graph also coincides with the PV dropping, which it usually does, so I don't think that's a great time to judge how much effect the fans actually made 

On 12.09.2017 at 9:03, Coulomb said:

Ei bine, conform acestei postări despre Pip-5048, probabil cea mai recentă versiune a Axpert:

http://forums.aeva.asn.au/viewtopic.php?p=65520#p65520 

„Și în sfârșit au pus ventilatoarele invers, acum atrag aerul rece prin partea de jos, iar căldura iese deasupra, așa cum ar trebui.” 

Remarc că radiatorul are capacitatea de a absorbi căldura în atmosferă, mai mult decât placa de jos. De asemenea, modelele mai noi nu au radiatorul în partea de sus, iar SCC-ul se află la mijloc între cele două radiatoare principale.

Hi. My easun smw8k is heating a lot. I turned upside down the 3  fans  and i put another 2 8cm fans upside, to take out the hot air, now the cold air enter downside and go.out upside. I think is better, what do o think ? Now stays in 43°C all the time. I will have false temperature ?

6 hours ago, add1c7ed55 said:

I turned upside down the 3  fans  and ... Now stays in 43°C all the time. I will have false temperature ?

Slightly. There is a temperature sensor for the main isolating transformer (I don't know how that works in models with two transformers). In 5 kVA models that I'm familiar with, it is located on the PCB below the transformer. So when the fans were pulling air down, this sensor would presumably see air heated by the transformer. With the air pushing up as it should, this sensor will mostly see air before it hits the transformer. So one of the 4 temperature sensors won't actually be reading accurately. But the other three (on the heatsinks for the battery, AC, and Solar Charge Controller), the temperature will just be as accurate as before. The temperature reported in the QPIGS command is the maximum of the four readings.

The transformer can operate safely at a higher temperature than the semiconductors, so this is not a serious side effect of correcting the air flow.

Edited December 10, 20223 yr by Coulomb