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Forum Index : Electronics : A birthday for my Kipoint inverter

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Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 08:34am 11 Jun 2022
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G'Day Guy's,
           Well back in early 2004 I sent an email off to Taiwan for a quote on the spec's of a 3Kw inverter and the answer was $999.00 US for it. Now bringing it thru customs I was asked what is this item and when I said you connect this to a battery bank and it puts out the mains voltage. I had to say that about 7 times then got told as we don't have a listing for this item the max customs charge will apply. In the end it cost me $1,500 and it did some time to get this released.

Now as this inverter has served me very well when it comes for big loads it just won't drive them and goes into over current mode and I did find I had to tweak the voltage setting as it was outputting over 300 volts and thats why the VFD on my toolroom lathe went into fault mode.

Now my Lincoln i131 will work nicely but my 183 viper mig won't work at all, also my 8" grinder would set the inverter off too.

So my question is as the toroid is still working would it be worth using it with a new board so more modern electronics so I can get the surge current for the startup working again.

Cheers Bryan
 
Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 378
Posted: 06:40am 12 Jun 2022
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Hi Bryan, it may be that the batteries you have can't supply enough surge current for the loads you are trying to start.
I have 8010 based inverters running on my 24 volt system.
When I had powerjack inverters they died a few times because they did not like voltage dips on starting inductive loads. I used their transformers for the 8010 boards and tweaked some of the windings to suit what I wanted.
The biggest help my system got was by adding 500 farads of capacitors in parallel with the battery bank. The 500 farad capacitor bank only cost me about $170 and made a massive difference. My air compressor starts very fast now, as fast as it would on a really good mains circuit or better. No massive voltage dips caused by the large load.
So I would suggest trying capacitors first, you may find the inverter you have gets a new lease of life.
Pete
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 01:51am 15 Aug 2022
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G'Day Guy's,
           Over the last few days when I turn on this inverter it has gone into fault mode saying over current and no green power then it comes good. It did it again this morning so I took the cover off to find that relay that was going ratta tat tat when the fault mode was going.





sure enough there is a relay behind the transformer on that board but in order to get that board out means a strip down.

Here is a pic of the inverter




As we can see the windings are 4 inhand and 2 chokes are on the input where only 2 off 32 volt 15,000Uf caps are present.

There are 2 bank of mosfets




In this pic we can see the control card




I am hoping someone from the brains trust can explain the design of this inverter and maybe a close to 20 year old design could be a different way to make an inverter.

Cheers Bryan
 
Revlac

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Joined: 31/12/2016
Location: Australia
Posts: 961
Posted: 07:25am 15 Aug 2022
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If you can find a CT (current transformer) check the Burden resistor, diodes and associated resistors, there might be a trim pot there, see if those parts are in good condition or not, check values etc.
Unfortunately I think that would be too easy to find, if that is the cause of the over current fault, its likely something more difficult to find and fix.
Cheers Aaron
Off The Grid
 
rogerdw
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Joined: 22/10/2019
Location: Australia
Posts: 792
Posted: 12:07pm 15 Aug 2022
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  Bryan1 said  G'Day Guy's,
           Over the last few days when I turn on this inverter it has gone into fault mode saying over current and no green power then it comes good. It did it again this morning so I took the cover off to find that relay that was going ratta tat tat when the fault mode was going.



Hi Bryan, so I can get this clear  ...  you have the inverter off overnight  ...  and when you go to fire it up in the morning now, it has this relay clicking sound for a while???

And it eventually does start up  ...  then runs okay for the day ...  ???

Do you just leave it click away until it fires up  ...  or do you shut it off and try again a short while later?

How long do you have to keep trying before it does come good?
Cheers,  Roger
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 05:52am 16 Aug 2022
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Roger when I'm not in the shed the inverter is turned off and when enter the shed I turn it on, now today it started normally but that clicking sound was there for about 20 seconds then stopped.

now when it did go into fault mode after a short time it came good.

now yesterday I decided to measure the voltage at the power point and it was around 220 volts and today when I checked it 198 volts. In the past I have had the VFD on my toolroom lather go into fault mode and found the voltage was over 300 volts and taking off a rubber cover I was able to lower the voltage via a pot.

I have setup the output to come out the back of the inverter which goes into panel box with all the breakers and for the last 17 years it has just worked for me.
 
Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 378
Posted: 06:56am 16 Aug 2022
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Hi Bryan, you could try getting the cover off the relay and inspecting the contacts on it. It may be clicking because the contacts are burnt. A long shot but an easy fix if that is the problem.
pete
 
rogerdw
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Joined: 22/10/2019
Location: Australia
Posts: 792
Posted: 02:09am 17 Aug 2022
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Hi Bryan, Pete may well be right in his suggestion but I think the first thing that came to mind when you described the fault was that you may have a crook electrolytic or two in the control circuitry.

I'm not suggesting the big ones, I'm thinking maybe one of the smaller ones  ...  something like a 100uF 25V or similar.

The reason I suggest this is because after 10 years they can dry out or leak  ...  and often they will manifest as not functioning when first turned on from cold (worse on a cold morning)  ...  and work quite fine once they finally kick in.

Maybe when you come in at lunchtime on a milder day it will work first try.

While it is faulty, waving a hair dryer or hot air gun around specific areas can narrow it down  ...  and if you suspect particular caps, hit them with freeze spray and attempt a restart to see if they are the cause.

If you have an ESR meter it can be worthwhile doing a blanket check of all smaller electros which can speed up the process.

I also have to admit I was surprised at how good the boards look after 10 years of use, especially out in a shed. Some of the gear I see to repair that's lived in a shed for 10 years looks like it's been to hell and back.  

So for that reason, I'm sure there's plenty of life left in this inverter  ...  I wouldn't be thinking about ripping its heart out to build a different one  ...  not just yet anyway.
Cheers,  Roger
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 09:07am 20 Sep 2022
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G'day Guy's,
           Well last weekend decided to get on with that welder trolley and kept the same setting I used last time where the inverter played nicely but this time round from first contact with the wire inverter beep from overload then I could get a tack done then when trying to get a second tack the inverter would go into fault mode and need a reset to work again.

So it does look like the surge is dead and buried and I do need to try and find out where that part on the board is so I can start testing the components.

Cheers Bryan
 
Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 378
Posted: 11:53pm 20 Sep 2022
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Make sure that you test and check all the low voltage connectors. I have had inverters ( PowerJacks) that failed under load only to later find that the cables had got very hot where they bolted to the input connections.
See if the battery cables to the inverter have corroded or come loose.
Pete
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 09:12am 21 Sep 2022
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  Godoh said  Make sure that you test and check all the low voltage connectors. I have had inverters ( PowerJacks) that failed under load only to later find that the cables had got very hot where they bolted to the input connections.
See if the battery cables to the inverter have corroded or come loose.
Pete


The connection to the inverter is via an Anderson connection and I have 2 brass bussbars for each connection with 10mm bolts securing the other end of the cable. I do doubt it has come loose but I will check in the morning.

Cheers Bryan
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 12:50am 23 Jun 2023
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Well went to turn on the inverter this morning and looks  like it's finally had a good life as when turning the inverter on straight into fault mode and I reckon the hammering going on was the toriod as that relay clicking sound was also there. I had the cover off to get a better view and I notice the fet banks were getting nice and warm so that was it.

For the first time I saw the over voltage led come on blinking where the battery voltage was 25.1 so something really has gone astray.

Cheers Bryan
 
Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 378
Posted: 08:57am 23 Jun 2023
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It may be easier to re use some of the parts, like the transformer and case. Plus the terminals and fit it with an 8010 based chinese power board. All they need is a capacitor ( that they usually supply) an inductor and a switch and they are ready to go. Aliexpress have plenty.
Pete
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 11:39pm 23 Jun 2023
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Found this one on ali

24V 2Kw

Now it is very close to that pcb I have here and the link does explain all the details so I can use it as a reference.

Cheers Bryan
 
Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 378
Posted: 12:43am 24 Jun 2023
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Hi Bryan the inverter boards do go much bigger. I would try and squeeze the biggest board in that you can. Generally about 3kw is as big as I like to go with 24 volt but they boards do go larger, there is a 5600 watt board on Aliexpress too. Just depends on how much room you have.
ller,scm-url:1007.13339.291025.0,pvid:7c8b702f-1637-4f9e-b9f2-accf4024d697,tpp_buckets:668%232846%238115%232000&pdp_npi=3%40dis%21AUD%21241.99%21222.63%21%21%21%21%21%402101ec1a16875672045243217e6df1%2112000026254226056%21rec%21AU%21]https:

good luck with the inverter
Pete
 
Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1204
Posted: 01:09am 24 Jun 2023
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Hi Pete, I do have those 360 amp fets here and they should get the most out of that 3Kw aerosharp toriod I have here and as I already have that board here todays job is tracing all the tracks as I did print out that schematic Poida put up for me a while ago.

I got onto ali and grabbed a couple of EGS002 boards the ones that have the lcd readout.

Cheers Bryan
Edited 2023-06-24 14:56 by Bryan1
 
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