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stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 10:02am 26 Jun 2019
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I have had 3 of egs002 now. The first had no output on output 2. The second blew a pair of IGBT’s. The third blew a pair of igbts. I haven’t tried using the same one twice.
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 10:15am 26 Jun 2019
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Just looked. And that resistor (3 x 0.05ohm in parallel) is reading 0.2ohm
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 10:34am 26 Jun 2019
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Would using field stop trench IGBT’s make any difference do you think?
tinyt Guru Joined: 12/11/2017 Location: United StatesPosts: 438
Posted: 02:22pm 26 Jun 2019
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I don't know much about igbt technologies.
3 x 0.05 ohms in parallel is 0.016 ohm. I don't know if it can be measured accurately by a regular DVM. But I think they are OK.
What are the 2 orange capacitors? Where are they connected? I cannot relate them to your schematic.
Have you checked copper traces for damage? Is the output filter capacitor still good.
Most of the time, when I replaced components on a repair, I make mistakes. so re-check them.
Maybe the following steps will help:
1. Remove all igbts, remove the egs002 from the socket.
2. Ohm out the output terminals L and N and make sure they are not shorted together or to the chassis or to the heatsink.
3. Between the gate and emitter solder pads of each igbt, confirm the value of the resistor (4.7K in the schematic).
4. Between the gate solder pad of each igbt and the corresponding egs002 socket pin pad, confirm the resistance (5 ohms in the schematic).
5. Confirm the polarity of the diodes connected to the igbt gates.
6. With the igbts and egs002 still removed, power on the unit and measure the dc voltage across the output terminals, I am hoping it is zero or close to zero.
7. With the igbts and egs002 still removed and power is still on, measure DC voltage between battery negative and the gate pads of each igbts. I think they should be zero. Between battery negative and each of the output terminals should also read zero. Between battery negative and the collector pad of each of the two high side igbts should read 390vdc.
After you have installed 4 new igbts, confirm that they are electrically isolated from the heatsink.
Make sure you have thoroughly cleaned residual solder flux since your power voltage is 390vdc.
I don't know the mounting feature of your inverter. Maybe when you mounted it in the wall, the mounting hardware touched an electrical circuit or something.Edited by tinyt 2019-06-28
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 03:24pm 26 Jun 2019
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Sorry. I missed them in the schematic. But they go between dc live and emitter 1 low and 2 low
Gate to egs002 are reading 5.6ohm (my dmm is not 100% correct)
All output caps are reading within spec
Output L to N is reading 6mohm
Gate to emitter resistors all read 4.689kohm
Confirmed function and polarity of diodes
Powered up, output L and N read zero
Gate pads to battery ground read zero.
390v at collector high pads
I don’t have any new IGBT’s yet to test for isolation
tinyt Guru Joined: 12/11/2017 Location: United StatesPosts: 438
Posted: 03:33pm 26 Jun 2019
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OK. When you have new IGTBs installed, Don't install the EGS002. Power it up (I think it is safe since the IGBTs should not be on) and carefully measure dc voltage between battery gnd and the output terminals. Also carefully measure dc voltage between battery gnd and any terminal of each of the gate diodes.Edited by tinyt 2019-06-28
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 03:55pm 26 Jun 2019
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Would it be battery ground though? Battery ground is isolated from everything after the transformers
The spwm is powered via a secondary winding in 1 of the 4 transformers
tinyt Guru Joined: 12/11/2017 Location: United StatesPosts: 438
Posted: 04:50pm 26 Jun 2019
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Whoops,
I forgot about the DC-DC converter. Please redo all measurements but change all battery ground references to the 3x 0.015 ohm resistor terminal.
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 05:24pm 26 Jun 2019
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I have just realised something. The IGBT’s used by the factory, have a built in diode between collector and emitter. Where as the IGBT’s I used, have not. But it worked fine for 3 weeks with 2 of them on high and low channel 1. Hmmm. Did I make a boo boo? Causing more problems? I will redo the tests shortly and report back
tinyt Guru Joined: 12/11/2017 Location: United StatesPosts: 438
Posted: 05:41pm 26 Jun 2019
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Just for me to learn more about IGBT. Do you have original part no. and replacing part no?
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 05:46pm 26 Jun 2019
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Original was a manga hip 60t65pes Replacement was a g30n60a4
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 05:53pm 26 Jun 2019
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I’m thinking the snubber diode as I just discovered its called, prevented reverse polarity through the IGBT I am also thinking it work for 3 weeks with 2 of the IGBT’s without the diode, is because they were only getting a pwm signal and not a spwm signal. So they were switching slower. But when I fitted the non diode IGBT’s in place of the originals on channel 2 hi low, the switching speed was too fast.
Still does not explain why the 2 originals blew when I switched it back on after mounting the inverter on the wall though
tinyt Guru Joined: 12/11/2017 Location: United StatesPosts: 438
Posted: 06:04pm 26 Jun 2019
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I am new to IGBT's so I cannot give an answer. Maybe the experts can chime in.
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 06:30pm 26 Jun 2019
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Really appreciate the help so far. More than I have had on any other forum
It is starting to look like I cocked up with the IGBT’s. All the schematics in the eg8010, show IGBT’s or fets with the snubber diode.
LadyN Guru Joined: 26/01/2019 Location: United StatesPosts: 408
Posted: 07:21pm 26 Jun 2019
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I am really happy with how things are shaping up for you - if the snubber diodes were all that you needed, I will be very excited to know that!
I apologize that I was selfish and tried to dissuade you from going down this path and build a LF instead.
I learned a few things, so thank you for the opportunity.
TinyT - you are an awesome person.
I'm almost considering buying a broken HF inverter from eBay so we can work on it together!
Alas, I have a few things I need to fix first. The TbsSSR (The back shed SSR) and then the HWH.
Good luck and I will continue to read with much interest!
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 08:39pm 26 Jun 2019
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No apologies needed. If you find that something is better than another for a given job and you know others who think the same, it’s natural to want to persuade others to join. I’m sure I would do the same had my budget covered a self build of inverter. But I do like the neat compactness of a hf.
From what i have learnt through trying to repair this invert, is that is quite often the output stage that goes wrong (dc-ac). Which in turn takes out fets on the dc-dc stage. Although that only happened once on my inverter as the over current shutdown took care of that. (Not via the spwm. But by a separate control card)
LadyN Guru Joined: 26/01/2019 Location: United StatesPosts: 408
Posted: 08:43pm 26 Jun 2019
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You are very gracious and kind.
I am starting to make notes from this thread and I have a question.
The board that came with the inverter looks like a EGS002 but plugging in a EGS002 does not make the inverter work at all?
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 09:12pm 26 Jun 2019
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The board that came with it is not an egs002. But has an eg8010 and 4 opto isolators. The same as one of the schematics provided in the eg8010 manual The egs 002 has the same pin configuaration The first replacement I got from the manufacturer, looked more like an egs002. This one had 2 2110 drivers instead of the opto isolators.
I’m now thinking the use of IGBT’s without the diode is why the egs002 did not work. And also damaged the driver chips on the egs002Edited by stockleys 2019-06-28
stockleys Regular Member Joined: 21/06/2019 Location: United KingdomPosts: 54
Posted: 09:31pm 02 Jul 2019
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ITS WORKING 😁😁😁😁
1 new egs002 4 new IGBT’s WITH the snubber diode And 1 new diode
Powered on. 240v. Whoop whoop
Been on since 11am. It’s now 10:30pm
Had the fridge on it, mowed the lawn running from it Tv is currently plugged into it. All is good Next test is the kettle (1800watt). The biggest load I’m Likley to put on it.
Thanks for all your input people. Great help. Really appreciate it
LadyN Guru Joined: 26/01/2019 Location: United StatesPosts: 408
Posted: 10:58pm 02 Jul 2019
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Brilliant!
All this for a few snubber diodes?
AMAZING! I am seriously considering looking into a few HF inverters now for a cheap unit.
Please keep us posted how this continues to work for you!
... and please, over the next few weeks, tell us what your power demands through the inverter is, as you discover it :)
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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