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Small Cabin Forum / Off-Grid Living / Inverter Kaputnik
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paulz
Member
# Posted: 1 Feb 2021 09:37
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Grrr. Looks like I'll be switching to a new pure sine inverter sooner than I planned. Yesterday I powered on my MSW inverter to the tune of snap crackle pop. Big sparks out the front. Had an LED shop light and a tool battery charger plugged in at the time. It has no fuse or circuit breaker, externally at least. Pulled the front panel off, tested the AC sockets for shorts.

Here's a quick video. Probably done for but let me know if there's anything else I can do.

https://youtu.be/5641z3R2ow0

Brettny
Member
# Posted: 1 Feb 2021 11:04
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You may need to pull the inverter apart further to find fuses or a circuit breaker.

Did you find a short? That's the noise it makes when its overloaded I assume?

paulz
Member
# Posted: 1 Feb 2021 11:18
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Didn't find a short. Those light bars are the DC input power, apparently it thinks it has too much. Some pretty good arcing and sparking by those bars, something probably fried but no smell or burns I could see.

gcrank1
Member
# Posted: 1 Feb 2021 12:36
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You'd think with all the snap, crackle, pop that it would have blown a fuse right away if it had one.
Am curious what went. May be a component just wore out.
Must be the time of the year for msw issues, just Sat my little 400w, that I only switch on when at the cabin, did a red light 'fault' with or without a load, with or without anything plugged in at all. Voltage on the bat-bank was normal (not close to the high or low limit of the inverter). Hooked up the spare and it worked fine.
Brought the faulted one home and it works fine on my jump pack battery. Hmmm
Being one's own power company has its challenges.

paulz
Member
# Posted: 1 Feb 2021 16:22
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Yeah, surprised there was no fuse type protection on the outside. Doesn't appear so, since it still does what's shown in my video.

So, if I'm getting a new inverter, I guess I can go 24 or 48 volt. But I also was running some 12v stuff off the input terminals on the inverter. Do the 24v have 12 volt takeoffs?

gcrank1
Member
# Posted: 1 Feb 2021 16:50
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If you input panels to mppt cc at the higher voltage you wouldnt have '12vdc taps' at input. Or are you stuck on staying 12v input/parallel panels?
If so, you have to stick with a 12v bat-bank dontcha (and thus inverter too)?

Nobadays
Member
# Posted: 1 Feb 2021 18:38
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Paul.... I run a 24v system in my shop and use a buck converter to drop the 24v to 12v. The one I have is a 40amp but they come in different amperage. I have a 600w PSW inverter that is 12v so until I can afford the 1200-1500w I want I just drop the voltage... but don't run high draw equipment.

HERE is the one I use.

ICC
Member
# Posted: 1 Feb 2021 20:19
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12 volts has its place; small cabins and cars/trucks. For anything with more than a pair of golf cart batteries for storage, I feel 24 volts in the minimum system voltage that should be used. Part of my own planning process is to try to minimize the number of parallel-connected batteries. That gets easier when the voltage is increased.

gcrank1
Member
# Posted: 1 Feb 2021 20:33
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+1 that
My place came with 4 x 130ish ah big ups 12 bat's all simple paralleled. CC into one end, dc taps and inverter hooked up that the other end. I suspect those bat's suffered because of that. Now 3 are done in and Im limping out the winter (but now we may not get back for a good bit).
Ive looked hard at various other ways to wire them and 4 just looks like too many to parallel tho when fresh I think that 500ish ahs had some beans.
I didnt really want to have to buy 4 new ones anyway.....but series/para for 24v would have better if I did and had to buy a new inverter.
Paul, your set up is substantially bigger than mine will ever be. But even for me the sensible thing to do is as things drop out to upgrade. For me that means LFP, were I you Id be going at least 24v.

paulz
Member
# Posted: 6 Feb 2021 18:38
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I dug a bit deeper in this inverter and found the kaputnik spot, same spot the spark show came from. Pretty big copper strip that fried. I was able to connect the two fried ends with a jumper wire and connect a battery, same warning buzzer and lights as the video, no change.

There's a few videos on fixing these Aims inverters I'll peruse before I trash it. It's just a MSW but it is a big one.
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paulz
Member
# Posted: 11 Feb 2021 17:42
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Hmm, good deal?
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ICC
Member
# Posted: 11 Feb 2021 20:15
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Depends. First of all, it might be misnamed. That appears to be a Trace Engineering 4048. 48 volt and 4000 watts continuous. A friend has two of them, stacked to provide 240 volts to the service panel. TRace also made 24 volt and 12 volt versions.

In their day these were the top of the line, the best inverter-chargers made. My friend has had his pair providing his off-grid power since about 2002. He bought his used from someone in AK who was upsizing with the then new Outback inverter-chargers.


Anyhow that is what I think this is. Does the seller indicate why they are selling or when it was last used? Seems a little odd with what the advert calls it and what I think it is. I could be wrong but it does look like the Trace units and I saw them both about a month or so ago so my memory is fresh. Maybe ask the seller for a readable picture of the specs label, just for the heck of it.

paulz
Member
# Posted: 11 Feb 2021 20:24
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Thanks ICC. Here's the ad, and a blowup of the tag. A lot to spend on used electrical that could last two days..

https://sfbay.craigslist.org/sfc/ele/d/nice-xantrex-pure-sign-inverter-55-48/72751958 39.html
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ICC
Member
# Posted: 11 Feb 2021 21:03 - Edited by: ICC
Reply 


Oh. OK. Maybe, it is a newer unit. Just looks a lot like the old ones that somehow came to my mind. That would need further searching.

It is 48 volts. That is good for a serious system. Are you ready to get serious?

paulz
Member
# Posted: 11 Feb 2021 21:29
Reply 


Ha, been asking myself that. With my limited sunlight I'm not sure I am. But it would be nice instead of inching my way up as I have been.

Question: I notice my panel voltage is sometimes around 50 volts, even though at max it should be 90. So with the MPPT it can convert that 50v into charging current for my 12v batteries, right? But what about if it was a 48v battery bank?

ICC
Member
# Posted: 11 Feb 2021 22:24
Reply 


Quoting: paulz
So with the MPPT it can convert that 50v into charging current for my 12v batteries, right?

Yes.

Quoting: paulz
But what about if it was a 48v battery bank?

That would be a problem. The solution is to have more panels in series to boost the input voltage. That might need a new charge controller. All the other limits like total wattage, etc would have to be observed.




If you went to a higher voltage battery bank you should have a hard look at what you need or want. Grid tie or no grid?

Creeping up on the end result often ends up with making compromises that can affect performance and satisfaction with the system. Other than checking once a day to see if the system is running more or less normally I don't think twice about the PV system or batteries.

Brettny
Member
# Posted: 12 Feb 2021 06:09
Reply 


Is that pannel voltage 50v loaded or open circuit? If open circuit it may not be enough for a 48v system. I believe the mac charging of a 48v system is about 52v..again 50v isnt enough. You may need to series pannels. Is your CC setup for two pannels in series with full sun? Your CC would also need to charge a 48v system.

paulz
Member
# Posted: 12 Feb 2021 07:42
Reply 


It's what the controller says, so loaded. It has a 100v max rating so I have 3 panels in series, which measure 90 something volts open, 4 strings of them in parallel. Depending on the time of day and brightness (they are all shaded, mostly) the controller will often show a voltage around 50-70, and around a 2 amp charge. Not much, but it does seem to be topping up my batteries when I'm gone for a few days, and it should get a lot better in a couple months.

I did try 4 panel strings and the sun hit one day and the controller shut off.

Sounds like with my sun situation I'm probably not ready for the big leagues. Oh well I have plenty of generators for heavy current needs..

Brettny
Member
# Posted: 12 Feb 2021 09:07
Reply 


The higher voltage input CC may help. 100v is the standard. 150v+ is not as standard.

paulz
Member
# Posted: 12 Feb 2021 09:43 - Edited by: paulz
Reply 


The CC in my shop is 150v, I have four panels in series there, about 130v, but haven't paid much attention to the load voltage. I guess I could use that inverter down there, since I have 4 12v batteries in the bank, just not sure I need to throw $1,000 at that. I think that may be a $2-3K inverter new, maybe now discontinued.

I replaced the dead inverter in the shop with a smaller 2kw MSW I got for $20 awhile ago, it's powering the LED shop lights fine for the moment but on the lookout for a PSW. I missed a couple of them on CL just before mine blew, not much lately.

Brettny
Member
# Posted: 12 Feb 2021 11:21
Reply 


I can understand not wanting to spend the $1k. We dont really see used inverters worth a crap go for sale here. Very low solar exposure in the northeast.

If I was to spend $1k I would be looking for one that also has a built in charger and generator start circuit...aka make my life easier.

ICC
Member
# Posted: 12 Feb 2021 11:37
Reply 


If your location has such lousy sun, paulz, why do you bother? Is there no grid power at all available at the shop?

gcrank1
Member
# Posted: 12 Feb 2021 11:46
Reply 


2 KW inv to just run lights?

paulz
Member
# Posted: 12 Feb 2021 15:40 - Edited by: paulz
Reply 


Quoting: ICC
If your location has such lousy sun, paulz, why do you bother? Is there no grid power at all available at the shop?


Lol, that sounds kind of odd coming from a solar proponent. You guys talked me into it! But it didn't take much.

Grid power is across the main road and a couple hundred yard up a steep hill. No transformer fronting my property. So a transformer, a couple of poles on that side, a pole on my side of the road, then whatever it takes to get it to a box. But I do like being off grid, it's a badge of honor, my buddies think I'm cool.

Actually what happened was: I went to buy a couple of cheap inverters on CL, $20 each. While there, the guy had this solar array he was selling for $300, already on a rack and a trailer. Looked like a good deal to me so I bought it, towed it to my place, he came and picked up his trailer next day.

Not more than a week later I was telling a friend about it, he mentioned his neighbor buying a house with a leased solar system he wanted gone (he was using the house part time, didn't want the lease payments, bought out the lease). So I got all that free, 30 panels, two grid inverters, blah blah, you may remember.

So I bought a couple of charge controllers, already had batteries, and here I am today. I'm getting good results even now for my needs, and for at least half the year I should get at least a few hours sun on them.

Quoting: gcrank1
2 KW inv to just run lights?


One of the $20 inverters. I could do more but after burning up a couple things with MSW I'm hoping to hold out for a new inverter.

Here's that $300 array, I have yet to hook it to anything. Except the dog.
buddysolar.JPG
buddysolar.JPG


gcrank1
Member
# Posted: 12 Feb 2021 17:11
Reply 


I only asked because I expect the overhead running that big boy is sucking up amps needlessly. You probably have enough array to cover it.
Fwiw, I have to watch out for 'good deals' myself....way to easy to collect too many projects

paulz
Member
# Posted: 12 Feb 2021 18:08
Reply 


That brings up a good point. I do notice when attaching cables to an inverter that's been sitting there is a pretty good spark. I assume that's capacitors inside charging, not a constant load.

I have been powering off my inverter every night and when not at the property. Sometimes I have left the lights switches on and tool chargers plugged in, so that when I do turn on the inverter it fires that stuff up too. Maybe that's bad and caused my other one to burn out?

Anyway I left this inverter turned on when I left yesterday, no load, first time I've done that. My shop batteries have been at 14 and change every time I've arrived lately, figured they could handle the inverter while I'm gone.

Brettny
Member
# Posted: 12 Feb 2021 20:04
Reply 


Sounds like you should be a pannel reseller and less of a user. Yes inverters have large capacitors and that's usualy why they spark.

ICC
Member
# Posted: 12 Feb 2021 21:35
Reply 


Quoting: paulz
Lol, that sounds kind of odd coming from a solar proponent. You guys talked me into it!


I am a solar advocate, but one does need good sunshine for at least a few hours a day to be a happy camper.

If you can have enough storage to carry at least one day's load, and have enough sun to re-charge them storage the next day while still using power for all your normal uses, then IMO, you have a nice workable system. At least that should be the way the typical day goes.

If you are always having to be extra careful about using power, needing to run a generator for something you often do, then something is wrong. Again, IMO. I like to have my solar but I really like that I don't have to baby my system. It babies me by providing almost worry-free power.

My biggest worry is lightning. I have done as much as I can with protective devices and earthing. In lightning season I think I monitor the Midnite SPD's more than I monitor the battery charge levels.


Quoting: paulz
I do notice when attaching cables to an inverter that's been sitting there is a pretty good spark.

That is one reason it is good practise to always install a DC rated breaker that is also rated for use as a disconnect between the batteries and the inverter. Repeated open sparking when connecting cables is not good for the terminals or the cable ends.

paulz
Member
# Posted: 14 Feb 2021 05:38 - Edited by: paulz
Reply 


Yesterday, in traveling on an unrelated matter, I looked at an inverter that was on Craigslist. Reliable WZRB 4k pure sine, $300. I had looked it up online, good reviews/bad reviews, the usual. I've been fortunate with the stuff I have bought from private parties, except the one inverter that fried and it was only $50, but I did not feel comfortable with this guy so I passed.

Thinking about going against my usual MO and buying a new inverter, maybe even from a local source, with a warranty. They do warranty them, for a year or so, don't they?

ICC
Member
# Posted: 14 Feb 2021 10:55
Reply 


IIRC, Midnite, Outback, and Victron are 5 year, Samlex 2 minimum depending on product line. I have one of their inverter/chargers in my RV and it had a 3 year warranty.

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