Smoked Lvyuan 24v 2000W inverter oops :(

[gloves12]

RIP my first inverter, sorry buddy!

My fault, ran a 900w microwave and a 1200w induction cooker at the same time; I was assuming the inverter's overcurrent protect would trip, but I burned it out bummer! The 24v inverter was behind a 150A fuse which wouldn't blow until 3600 watts, so next time I think I'll use a smaller fuse, too.

Looking at a Giandel 24v 3000W perhaps as a higher quality replacement.

 

[gloves12]

- actually, looks like the 2200W Giadel has pretty good overload protection that other users trust - like running a microwave + a toaster, it will trip and just make a sound, then come back on after a few seconds.

So I'll probably do that, behind a 100 amp fuse to be safer.

 

[WYtreasure]

Welcome to the party gloves12.

Did you get the "Magic Smoke" on video for us? Perhaps a fast blow fuse is in order. A couple extra bucks for an inverter with an alarm could be a nice touch too, if they exist.

 

[rmaddy]

A 2200W inverter on a 24V system can pull up to about 107A out of the battery and require at least 2AWG wire. Your main battery fuse should be 135A. Go with 125A or 150A since you probably won't find a 135A fuse. The fuse is there to protect the wire, not the inverter. Any inverter worth buying will not fry itself if you attempt to pull too many watts. It should simply whine and not provide the power. Or it may provide a brief (probably under 30 seconds) surge over the rated 2200W.

Cheap inverters should probably never be used at more than 80% of rated power. If you have a need to max out an inverter on a regular basis then you should buy a well known quality brand. I don't know of Giandel fits that or not.

Also remember that a microwave will have a large startup surge. Use the microwave alone or at least start it first. A 900W microwave might actually pull 1100W or 1200W too (not counting the startup surge). If you already have the 1200W cooker going, starting the microwave may require too much power due to the surge.

 

[gloves12]

No video sorry, if they invent smell-microphones I could record some, my basement still smells smoky lol :D

I'm using fuses like this that Will recommends, not sure if that counts as fast-blow? I was running 2100 watts through a 2000W inverter, so I don't think a fuse would have saved me - a fancier inverter is the plan, yeah!

 

[gloves12]

A 2200W inverter on a 24V system can pull up to about 107A out of the battery and require at least 2AWG wire. Your main battery fuse should be 135A. Go with 125A or 150A since you probably won't find a 135A fuse. The fuse is there to protect the wire, not the inverter. Any inverter worth buying will not fry itself if you attempt to pull too many watts. It should simply whine and not provide the power. Or it may provide a brief (probably under 30 seconds) surge over the rated 2200W.

Cheap inverters should probably never be used at more than 80% of rated power. If you have a need to max out an inverter on a regular basis then you should buy a well known quality brand. I don't know of Giandel fits that or not.

Also remember that a microwave will have a large startup surge. Use the microwave alone or at least start it first. A 900W microwave might actually pull 1100W or 1200W too (not counting the startup surge). If you already have the 1200W cooker going, starting the microwave may require too much power due to the surge.

Nice totally, makes sense about the microwave, thanks! I've got a 150A fuse atm, and I over-gauged my wires with 2 awg (that was a pain in the butt to work with lol).

 

[rmaddy]

and I over-gauged my wires with 2 awg

2AWG isn't over-gauged at all, at least not with a 2200W inverter. You might have been OK with 4AWG with the 2000W inverter.

 

[gloves12]

Nice! Cool beans. Yup, Will used 4AWG in his tutorial but the hardware store had a 10-foot remnant of 2AWG at a discount so why not be a bit safer.

 

[Bud Martin]

900W + 1200W on the AC output of the inverter, that means the power on the DC input of the inverter is about 2100W/0.85 = 2470W
BTW, the inverter has a bunch of internal fuses, did any of them blown up?

 

[rmaddy]

900W + 1200W on the AC output of the inverter, that means the power on the DC input of the inverter is about 2100W/0.85 = 2470W

On a 24V system that's only about 100A so not too bad on its own.

 

[gloves12]

900W + 1200W on the AC output of the inverter, that means the power on the DC input of the inverter is about 2100W/0.85 = 2470W
BTW, the inverter has a bunch of internal fuses, did any of them blown up?

I was hoping it was just a fuse, but it definitely smelled like magic smoke. I'll open it up and see, that would be sweet if it was just a fuse but I'm not overly optimistic ?.

 

[gloves12]

900W + 1200W on the AC output of the inverter, that means the power on the DC input of the inverter is about 2100W/0.85 = 2470W
BTW, the inverter has a bunch of internal fuses, did any of them blown up?

So, the inverter has 6 x 50 amp fuses, and it even came with a full set of spares; unfortunately none of the fuses blew.

One of the big capacitors is bulged, and the circuit board nearby is scorched. Maybe I can solder on a new cap, but not as simple as just a fuse sadly!

 

[gloves12]

actually, seems like the mosfets are most likely the culprit. Something like this may work:

I'll have a go

 

[Symbioquine]

seems like the mosfets are most likely the culprit

I was about to post the same. The mosfet behind your screw driver point in the second photo definitely looks burnt out - and maybe the mosfet/resistor between E5 and E6 also.

I'd be curious to hear if it works once the cap and that/those mosfets are replaced. (Hopefully and easy fix... ?)

 

[Symbioquine]

Actually, I just noticed from the first photo that the mosfet between E5 and E6 is almost certainly toast too;

 

[Bud Martin]

I will not be surprised if the MOSFET shorted out, so they parallel two 50A fuses for each Voltage booster circuit (there are 3 of them).

 

[gloves12]

Totally! Sounds like a fun project, I'll give it a go. Thanks for giving the pics a look!

 

[gloves12]

MOSFETS are tricky to buy, gosh -- I think I found a good replacement mosfet that I can purchase, does this look okay? The only issue is it has a slightly worse resistance rating (6.8 milliohms vs 4.5 milliohms) but the original handles less current, so if I did the math the new one may still be okay; maybe better.

 

[Bud Martin]

So the MOSFET has shorted out between D and S? G and S? G and D?

 

[gloves12]

Good question - I think several the 12 mosfets burned, at least one per each of the 3 transformers - the insulation is melted off the third pin (source pin):