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Jaffasoft Senior Member Joined: 03/11/2010 Location: AustraliaPosts: 102
Posted: 10:06am 10 Dec 2017
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I've just blown the third inverter in about as many years but this one lasted about 2 years. I went through two before that in about three months. Despite conversations with Jay Car salesmen that they were blowing up and i thought it was the 15v plus current doing it, they assured me that was normal and that "these" wont blow up.
I'm sure it's because i am using a Charge Controller that charges T105 Deep Cycle Trojan Batteries in at up to 15.2 at times with temperature compensation in cold weather. Trojan recommends charging in at 14.8 so that's what i do with a TriStar TS-45 Solar Controller. I think i has a thread about this before i should have dug it up!
I've been buying a 12V car inverter ( a different band each time) and connecting them direct to the battery. I think the solution might be to put a regulator in the line same as the old holden cars had them, wish i could find one now. But i'm certain this must be why it's blowing inverters or are they just made sh*t these days. Seems they are rated at about 14V but this last one was rated at 15V maybe why it lasted.
Can anyone shed any wisdom on this and what i should be? What brand to buy i only need to charge the laptop and run a 140 watt ebike battery charger and usb 12v light and charge iPhone, a small drill from time to time if ever drilling a screw in. 600WATT with 1200WATT surge pure sine wave work good last time but as i say two years and it's blown up. This one: https://www.giandel.com.au/product/giandel-pure-sine-inverter-600w-12v-ps-600da12v/
hotwater Senior Member Joined: 29/08/2017 Location: United StatesPosts: 120
Posted: 06:11pm 10 Dec 2017
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I have doubts about that theory. I don't even buy an inverter unless it is broken. The input should easily handle 20V as the FET are 60V. I've found the voltage rating on the output FET pretty minimal. Either input or output FET will fail, just cause. Heating is usually a problem with these. If it is now "junk" I can walk you through finding the problem should you have even a cheap meter. It could be interesting Most problems are't rocket science. Does it power and go into fault? That is generally two output FET.
Jaffasoft Senior Member Joined: 03/11/2010 Location: AustraliaPosts: 102
Posted: 10:49pm 10 Dec 2017
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Yes, I have a cheap meter and ready for a walk through to give this a go thanks.
Jaffasoft Senior Member Joined: 03/11/2010 Location: AustraliaPosts: 102
Posted: 10:54pm 10 Dec 2017
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It powers and goes into fault! As soon a the switch goes to ON it is continuously beeping with a fault alert and sounds though a fan comes on. The outside weather temperature isn't all that hot here and the system when in use didn't ever seem to get hot.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 10:01am 11 Dec 2017
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I have a giandel inverter in my caravan, it seems to have lasted well as I don't stress it. It's a 2800w continuous and the most it cops is a 800w toaster. One curious thing I noticed is that the fans sucks air out of the unit. Wouldn't it make more sense to blow air over the parts and exit at the other end via vents? Having a small fans at one end sucking out seems like a dumb ass idea. Surely air flow OVER the internals would make more sense.Cheers Caveman Mark Off grid eastern Melb
Jaffasoft Senior Member Joined: 03/11/2010 Location: AustraliaPosts: 102
Posted: 10:08am 11 Dec 2017
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Don't know what the theory is with the airflow.
I bought a 400WATT POWERTECH Pure Sine Wave Inverter straight off the shelf today at Jay Car for $250 because i had to get this show on the road again and LapTop charging again. 12 Month Warranty.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 10:18am 11 Dec 2017
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Why don't you just run a 12v charger for the laptop?Cheers Caveman Mark Off grid eastern Melb
Jaffasoft Senior Member Joined: 03/11/2010 Location: AustraliaPosts: 102
Posted: 11:10am 11 Dec 2017
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Because i couldn't find a 12V one to buy for Apple Mac air then i'd have to buy an inverter to charge the eBike battery. Then 240v drill for tech screws now and again.
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 11:44am 11 Dec 2017
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Don't you think that the air replacing the one being sucked out *does* flow over the internals? That is, if the thing has been designed properly in the first place.
My personal preference is an exhaust fan at the top with fresh air inlets at the bottom of the unit. This way the hot air rises principle works most efficiently.
I do have a MPPT regulator (Australian made) where the fan was located on top. But it was blowing air in, against the hot air rises principle. I simply turned the fan around to suck air out and the unit runs much cooler now. Don't know if the fan was fitted the wrong (IMO) way round accidentally or intentionally.Klaus
hotwater Senior Member Joined: 29/08/2017 Location: United StatesPosts: 120
Posted: 02:57pm 11 Dec 2017
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I have almost the identical converter, same printing but stamped with another name. Remove the screws o both ends and the bottom will come off. I found it easier to remove the assembly with the switch and USB port from the end plate. On the sides are several screws that hold the FET pressure plates. The FET can then carefully pryed off the insulating tape. Heat sink compound kinda makes them stick. Only have to be pryed back a mm or whatever you use over there. The board will then slide out of the case.
If it powers up at all, then it is likely the high voltage H bridge FET. There are four on one side. Measure resistance from the two outside pins of each FET. They usually blow in pairs. There are videos on youtube for GTI and inverter repair if you want a visual of the testing process of FET.
If the fuses blew then it is the FET on the other side. A cheap suitable replacement is about $10 for 10. Any cheap FET is dubious, but this not a critical application. I prefer not to remove the leads and just cut them. Surface solder on the new ones. The plating on these boards is minimal and the pads are likely to lift from the board if the leads are removed. The case hides everything.
Tell me what the FET is. In 120 land they use IRF644. The voltage would have to be at least double that. I've used 20N60C, but that is in a larger package and have to run wires to it.
If you are artistic and have the files, remove every other divider on the end for better air flow.
Edited by hotwater 2017-12-13
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 07:27pm 11 Dec 2017
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Yeah I'm sure it does to some extent, but wind chill factor would help cool them better. If you got a metal box, cut some vents in the bottom and a fan at the top sucking air out, then stick a soldering iron in the middle, you would find the soldering iron stayed hot. However, if you flipped the box up the other way and have the fan pushing air in and blow air directly over the soldering iron it would be way cooler.Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 10:31am 12 Dec 2017
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Good point about that 'wind chill' factor. However, with a box usually crammed full with electronic parts, some getting hot, some not, it is not always practical to mount those getting hot directly in front of the fan. Certainly not if there are many parts that are getting hot.
What does help is if there is a heat sink that's arranged in a kind of 'tunnel' and the fan blows cool air through it from the bottom side.
That is how I arranged the internals of my monster inverter. But there are still two extra fans sucking the hot air inside the enclosure out on top. Without these running, tests confirmed that with a high load the inverter's internal temperature keeps increasing slowly and starts dropping as soon as the exhaust fans come on (they have an independent temp. switch from the heatsink fan).
Klaus
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 10:39am 12 Dec 2017
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Don't worry mate, us Vic's know all too well about wind chill factor, but the principle still works on hot components.Cheers Caveman Mark Off grid eastern Melb
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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