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Forum Index : Electronics : Cooling Large, 6kW, Main Inverters & Install Info.

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Clockmanfr

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Joined: 23/10/2015
Location: France
Posts: 427
Posted: 06:33am 26 Aug 2021
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I thought that some Forum members might like to read this.   Something i did recently for some French folk, this is the English version.  

It relates mostly to the 6kW-15kW, 50kW surges OzInverter, but it covers information about most Inverters Installs.


COOLING A MAIN POWER INVERTER .

My personal experience and observations after 15 years of making, installs and running Inverters, and having that vital Empirical Evidence.

I have put this together for others, this all may seem 'common sense', to most of you, but to get that 'common sense' you need actual hands on experience information.

1.     Your main Inverter 48v DC to 230v AC 50HZ, (or 120vac 60HZ in the US), should be kept cool at all times.
2.     Firstly, DO NOT INSTALL the Inverter in the same room or compartment as the batteries.
3      Your Inverter should have good access to air flow.  But keep the weather elements away from the actual machine.

Excess heat in your inverter when under load, will lead to rapid wear down on the electronic components, notably the Capacitors and the toroid windings.

Ensure that the enclosure for the Inverter allows good air flow, for the PCB's and the toroid. And for the 6kW OzInverter I recommend the double Ozcooling circuit that's temp and delay adjustable, for sucking in with a 120mm diameter fan at the bottom blowing air direct onto the toroid and another sucking the air out at the top of the enclosure. And 2 more 120 mm diameter fans with the PCB boards that are fastened vertically.

Use stainless steel insect mesh to stop spiders etc from getting into the Inverter machine. As Oztules found out, "The local moths liked my LED's on the control board and snuggled up to it until the Control board shorted out."   Keep the insect mesh clear, its surprising that insects and debris soon clog the mesh.





Batteries, especially Lead Acid need to be in their own separate environment, with lots of air flow to disperse the Hydrogen that is given off.  The Inverter and the Inverter main fuse should be in their own separate environment.

I have seen Blue gently glowing balls of methane and hydrogen slowly ascending from our open ended battery shed on a still foggy autumn evening, they dissipate at about 10 meters high after 10 to 15 seconds.
I have also seen that when a main 250amp breaker has been engaged in the battery room, for just a split second all the spider cobwebs glowed, so not a good idea to have electrical connections in the battery room.



 

For a permanent 24/7 inverter installation, a good solution is to have the Inverter the other side of the wall to the battery room, this keeps the 70mm/2 cable reasonably short, so voltage sag is minimal. And have the Inverter in a good weather/rain proof cabinet that keeps it dry and protected from beast and small animals, but importantly allows lots of air to flow around it.
Ensure your cables are encased in cable protection from the 'furry critters'.



 

Now some of you may say, "I will have the inverter inside my house", well firstly, the constant very gentle Hum from the hand made toroid and the Choke assembly are always there, and with commercial manufactured inverters under heavy load can sound like a bag of spanners.
Edited 2021-08-26 16:38 by Clockmanfr
Everything is possible, just give me time.

3 HughP's 3.7m Wind T's (14 years). 5kW PV on 3 Trackers, (10 yrs). 21kW PV AC coupled SH GTI's. OzInverter created Grid. 1300ah 48v.
 
Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1577
Posted: 07:14am 26 Aug 2021
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  Clockmanfr said  

Excess heat in your inverter when under load, will lead to rapid wear down on the electronic components, notably the Capacitors and the toroid windings.


Seemed pretty obvious to me so I have a car radiator fan on all my Commercial ( forgive me) GTI's.

In summer when running flat out ( I have them all well overclocked) they would get so hot you couldn't hold your hand on them and even an electronic Dunce like me knows that's not good.... except to ensure replacement sales for the manufacturer.

The radiator fan is located above the GTI's and just connected to old panels. This gives them the perfect automated control even though they are direct connected.
The temp difference it makes to the inverters is Huge.  They never seem to get as hot in the winter and that's not just the ambient Difference.  I suspect  They have a dissipation range and a good 40oC  day here pushing them well over that.  The fans  have them at ambient temp instead of double.

The forced air covers the whole surface of the GTI's due to the fans size. Blows on the front and sides as well as through the fins at the back and I think there is a lot of heat dissipation on the front and sides.  I did make a shroud to direct the air down the back of the first unit but although the air through the fins was much greater, the rest of the unit ran much hotter.  I removed the shroud and let the air blow all over as that seems to make the things run coolest over all.

The heat that comes out of them is amazing. I have trouble believing the rejected heat is equal to the stated  efficiency and power levels. Should be a couple of hundered watts, feels more like a Kilo at least to me comparing them to an electric fan heater.

The other thing to remember with the commercial GTI's is they start  pulling back at fairly conservative temps. The cooler you can keep them the more power they will produce without clipping or limiting.

The fans do roar a bit when they are flat out but that doesn't worry me. I like the sound of work being done and knowing I am giving them the best chance of longevity.
I found another use for the fan panels over winter as the inverters were running cool enough, I used them to charge the battery my Diesel heater was on.  That's run about 85% on solar as well all winter.

We got a warm day earlier in the week, about 27oC and I noticed how much  the inverters had warmed. Won't need the diesel much more so can swap back to the  Radiator fans.

I have a pair of those in my garage window on a couple of shattered panels. They have been there 4 Years now and I didn't even disconnect them this winter.  They were off a 15 Yo car when I got them and I had them at my other place at least 3 years running off a power supply.  The longevity of these things blows me away.
I have had them running very hard in the summer off 30V panels  but it does not seem to have worried them. They sure make one hell of a different to the shed temp though in summer. It's very pleasant to be in rather than an oven.

Seems to me the cooler you can keep any electronics the better and there is no comparison between forced air cooling and convection.
 
BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 961
Posted: 05:53am 02 Sep 2021
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How many mosfets does your 15k inverter
use

I have switched from hy4008 to 360 amp
hy5608

I have melted the solder of the legs puddle up underneath with out blowing them when testing new awesome things

I have a friends new giant 25 or 30k
Power jack on my bench trying to find out why it and many other gaint ones won't start a central air unit

It has two main board in it and the central air unit I think is 2 1/2 to 3 ton unit

This is a common problem with power jack
units with WELL over a 100 pound transformer

Another kind of inverter is blowing fets trying to start big central air units

The pj shuts down without blowing fets

Many different very large pj inverters and many different central air units

The one blowing fets is very large also

Any advice would be greatly appreciated
be warned i am good parrot but Dumber than a box of rocks
 
Clockmanfr

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Joined: 23/10/2015
Location: France
Posts: 427
Posted: 08:40am 02 Sep 2021
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We have 24 FETs.

These are my standard boards, and also use these for the 8kW to 20kW OzInverter.

But to be honest, even with my large system, the 6kW-15kW OzInverter handles everything without issues. Where the 8kW-20kW requires a fair bit of extra work, and the toroid becomes about 50kg, that's 110lbs in your money, and becomes a hassle mounting it safely.  So i no longer recommend the 8kW-20kW.









Everything is possible, just give me time.

3 HughP's 3.7m Wind T's (14 years). 5kW PV on 3 Trackers, (10 yrs). 21kW PV AC coupled SH GTI's. OzInverter created Grid. 1300ah 48v.
 
mason

Regular Member

Joined: 07/11/2015
Location: Canada
Posts: 86
Posted: 10:12am 02 Sep 2021
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Ben are you using the control board with all the little green LEDs? If so that is one of your problems there..
 
teapot
Newbie

Joined: 22/08/2021
Location: United Kingdom
Posts: 22
Posted: 05:47pm 02 Sep 2021
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Can never have too much cooling. My lightly modded PJs have resistors which run the fans at about 50% all the time, and 45C thermal switches on every heataink and magnetic component to switch to full speed. I used Delta 24v 1.5A fans as I don't trust PJs stock fans.

I also noted that PJ boards have no thermal conductive compound between the fets and heatsinks. I also added a high quality compound used for overclocked PC builds to ensure adequate heat transfer.
Edited 2021-09-03 03:49 by teapot
 
nickskethisniks
Guru

Joined: 17/10/2017
Location: Belgium
Posts: 405
Posted: 06:14am 03 Sep 2021
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Watch out with using thermal compound if your heatsinks are used as conductors too. Then you will need a compound that's conductive.

BenandAmber, aren't that those genetry inverters that are blowing? I need to watch those videos again to say something useful about it. They are not making those inverters like we are doing here, and they should read up all the tips and tricks to be found on this forum. It's possible if they just use like for example a better series inductor the problems will be gone.
 
Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 372
Posted: 06:57am 03 Sep 2021
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BenandAmber, what supply voltage are those 25 kw inverters.If they are 48 volts then they would be pulling 500 amps from the batteries at maximum power.
If they are trying to start a large air con unit then the current draw would be much higher.
So it will depend on the battery banks capacity to supply current, whether the inverter can start things or not.
Best way is to try starting a big load and testing the battery voltage.
I have a 24 volt system and recently added a 500 Farad capacitor bank to supply starting currents. They sure make the 8kw powerjack much happier when running my air compressor.
I actually de rate powerjacks to around 25% of the label, so I call my 8kw unit a 2.5 kw max unit. It seems to be fine at that rating.
Pete
 
Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1577
Posted: 12:24pm 03 Sep 2021
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  BenandAmber said  

I have a friends new giant 25 or 30k
Power jack on my bench trying to find out why it and many other gaint ones won't start a central air unit

It has two main board in it and the central air unit I think is 2 1/2 to 3 ton unit


That's not a very Big AC.  Clueless ignorant here on inverters but I Know a little about AC and -IF- the Inverter is actually capable of supplying 25KW, there should be no reason it couldn't start a 3 ton AC. Would it even pull 15A running assuming single phase? Even starting on Compression, cannot see how it would not start on a lot less than 25 Kilo unless the reactive power of the inverter was totally crap which in my experience with cheap commercials ones are not bad.

My amateur way of looking at this would be to look at the cables first and foremost.
How long is the cable from the inverter to the AC and what Gauge? I'd be making sure there was plenty of overhead there. If the inverter is voltage dropping then the amps could skyrocket.

Similar for the DC side to the Inverter.
I'd also be Booting the AC with a Clamp meter and trying to get a peak reading on amps and a low reading on voltage.  Could well be it's not the inverter but simply the cables either side of the inverter. If the voltage drop at the inverter is not a lot but is at the AC you have your answer.

If that checks out then Caps, a VFD or a setup like a rotary Phase converter might do the trick.  Have an AC Motor, Pref 3 Phase, Running near the AC and have a large Pulley or Flywheel on it.  Put a delay on a contactor for the AC compressor .  The motor spins up, the timer Boots the Compressor, the Motor supplys reactive power to start the compressor and then the  timer shuts the motor down till it's next needed. Caps can allow a 3 Phase motor to run off a single phase input but once running with no load will run fine off single phase only. Tap off one leg back to the AC Compressor.

A Soft start or a VFD would probably also overcome the startup power hit if the problem is the inverter surge rating and not power drop through the cables.  

The other question amateur me would look at was what else the inverter was supplying when the AC was trying to boot up?
 
BenandAmber
Guru

Joined: 16/02/2019
Location: United States
Posts: 961
Posted: 04:10pm 17 Sep 2021
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Mason I run a 4 hy4008 in total esg002 inverter little China board

It has gave me no problems at all it is whay better then is believable

I also have a 24 hy4008 esg002 inverter
Tranny is around 70 pounds it will run 10k
It also is a awesome solid inverter also

I have some really awesome Genetry solar boards on a tranny I built

It has everything including wifi scope and you can custom set anything

The GS 6k has a multi tap Transformer so it can be changed with to any battery voltage

It has lots of room for custom settings

I have ran from 26 to 32 volt low side trannys on it you can be running a 4 or 5k load and start a big air conditioner
It also has low idle current

You guys and me also would use a bigger tranny on the 6k GS but it has been tested over and over at 8k

So it is nothing like a PJ it is a amazing inverter

I tried countless choke materials Henry's and turns

I couldn't do better than Factory setup I think it was around 0.40 of a amp

I was trying to blow up on PURPOSE the genetry solar boards i even shorted the high side to its self WHAT A SHOW
After that sid through the internet turned the protection software back on

I was full open no watage voltage or amp limit for many many months

I think it is at 10k now yes for a 6k inverter lol

It is a incredibly tough set up
I did loads of ridiculous stuff and I have lots of videos to upload some day

Davo I agree and I wouldn't expect glens big Pj to do over 12 to 15k

I have ran into many people having the start up problems with some of these big pj units

It could be they was winding a 32 volt low side on some of them for a Wille and with lead acid batteries big sag it turns to a square wave literally!!!

I am waiting on the soon to come 12k new bigger GS boards I don't trust the two main board pj set up

The inverter board that was blowing was trying to start a crazy be likely over 20k start up load out side condensing unit

They got that one fingered out and started  it up but thay had programming limited to 16k so it was slow starting

And it was just testing it will get abused  right soon no limit he he he

I think I answered godho question
Sorry so late to reply I am not on here very often anymore

I did also live out a few inverters I am in the middle of like the now two heavy to move going to do my best to blow up sid boards tranny I think it will be 120 to 130 pounds when done

Like usual I wrote a book sorry
I hope and pray things are good or getting better for many good people on here
Edited 2021-09-18 02:25 by BenandAmber
be warned i am good parrot but Dumber than a box of rocks
 
BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 961
Posted: 06:50pm 17 Sep 2021
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Davo that 3 phase motor is pure genius
Many people could use something like that in many ways even kinda like the guys on here use grid tied inverter by spinning it a little over name plate rims
It could even start the gas motor

Nick no there is no GS inverters blowing up a prototype 12k inverter Board blew up a few times tried to start a crazy big Central air unit

They found the problem and started the unit he currant limited for that test at 16k and the unit started were slowly

The tranny was complaining somthing fierce
For a few seconds but you can't kill the GS inverter it just takes it

I hove done way worse 100 of times for way longer dancing groaning tranny if you over amp the mosfets on purpose if you try hard without current limits you can blow them

But it would be a very rare likely never thing to blow anything else

The GS is very good!!!!

The video of central air start up is on you tube and the blowup also

I missed Mason

no I don't like PJ boards I have had a few a long while back 3or4 of them

All the ones I have had heat up one bank of mosfets

The last one I had sid hacked into it and rewrote the soft where

After that no more hot fets and a absolutely perfect sine wave

The tranny was one I wound also

I the trannys I have wound are completly salient  

I couldn't even us any of the pj cores I had there would be hot spots in the core itself

Pj cores are way better now
The big tranny I am winding now is a pj core

I have rewound I think 6 of the newer pj cores now they are very good cores

I plan on at the very least changing glens big pjs control board

Glen has a GS lcd wifi board he also has the pj control board sid rewrote the programing on

I will put them in Glens big pj if I have to

I will definitely be taking one of the two mosfet boards out though

I am still have two inverters with the power jack mosfet heat sink board

But I haven't used the power jack little mosfet boards for a long time

I use the ben and amber little mosfet boards that kent made for me

They use the 247 big size mosfets
Like the hy4008 or better yet the hy5608

They fit and work better than the pj ones he done a incredible job designing them

They are much cheaper also I have gave a bunch of them away and people love them

Ben and amber boards with the 360 amp hy5608 are the ones I melted the solder off the legs of

I shorted the high side of a big tranny to its self and it jumped around shaking the shed and sounded like a passed T-Rex

It was incredible I was stunded at the site and stared like a boy seeing boobies

It did this for what seemed a long time and I was using the gs boards

The gs boards are incredibly tough!!!

the hy5608 is very tough also but with a deafing bang full of shrapnel two maybe three desided to move into skin and dry wall

I made fun of sean being so gun shy for ever I definitely understand and now use safety glass

Them are some nice inverters you build Clock man I should not say this

but I remember that guy who got mad the inverter board didn't have all the components on them I couldn't believe he wasn't joking lol

I know your not in the market for a inverter but you might enjoy taking a look at the genetry solar inverter

Being able to see everything and change anything from your phone is a big deal for those with pets
Especially in a rv

These thing is not as big of a deal to you guys on here

But when you consider what sid has done at the price point has do it at

You might be a little impressed

Most newbies end up having to buy a new inverter or ride out a lower battery voltage way to long

Not now with GS just pop the top switch your low side winding to the voltage you want

He has terminals in there so it makes it really easy

Also you get a low frequency pure sine inverter with a good warranty that can run well over its 6k rating 24/7

I have 4 people at home in my family we could do fine with a 3k if it wasn't for those very short times things will overlap

like ac running and microwave then the refrigerator kicks on also the 6k allows lots of head room and will be great for many people

I don't think anyone on this forum would say pick a inverter that runs full out most of the time

This is why I think sid has hit a very sweet spot when you consider all the above and the around 1k price

This inverter will save alot of money for many people and it is tough and will last

My two cents and likly many others when all is considered
Edited 2021-09-18 05:54 by BenandAmber
be warned i am good parrot but Dumber than a box of rocks
 
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