Outback 3000 Watt Inverter Question

[DigitalMind]

Hello,

  I am helping some people via email who are setting up a solar system in Spain.  I'll eventually put up a link for the write-up of their install, but until then, a quick question :

They're using an Outback 3000 Watt 24 volt inverter.  They've got it connected to a 24 volt 1000amphour battery bank.  The panels, charge controller, and battery bank are all working so far.  

I'm not sure why, but they connected a 25 AMP fuse in between the batteries and the inverter.  Although that 25 amp fuse if OBVIOUSLY way too low for a 3000 watt inverter, (They just ordered a BIG fuse from outback now)  I would have thought that with no load connected they'd atleast be able to turn it on, but no.  The breaker goes back to the OFF position as soon as it's turned on.  Is this normal ? Does the outback do some kind of power tests as you turn it on that would take more than 25 amps ?!  (Outback inverter model VFX3024e)  They seem VERY VERY sure of the connections between the inverter and batteries.

They haven't grounded the negative terminal of their battery bank yet either, would that have anything to do with it ?

Thanks as always !

[TomW]

Mind;

Well, almost every inverter I ever used had a big surge on connection to the batteries.

I believe they charge some big caps across the input or something.

I think it is "normal" for there to be a large inrush of current on initial connection.

I also suspect if it is a breaker and not a fuse that they could have reset it a couple times and it would have filled those caps and fired up.

Anyway, thats my theory.

Good luck with it.

I know remote troubleshooting is a tough nut to crack with non technical folks on the remote end.

Tom

[DigitalMind]

Thanks a lot Tom.  I was hoping it might be something like that.

I don't know what I'd do without you and the rest of the people here with lots of experience !

[ghurd]

I though that too.

But it sounds like the inveter is already connected, and the fuse/breaker pops when the unit is turned on.

Is it a fuse or a breaker?

G-

[DigitalMind]

It's a breaker.  I had them do that test too.  With the inverter UNPLUGGED, the breaker stays on.  With the inverter plugged in, it'll go back to OFF position right away.  I don't even think the switch for the inverter is in the ON position yet though. (But I could be wrong about that, I'll have to check that out)

Jason

[TomW]

G;

I assumed it was just connected fresh install from the post.

We all know what assuming does, of course.

The surge filling a big dog cap bank is hard and fast as you know.

They even have current limiter devices to connect between those car audio caps and batteries to eliminate spot welding the connector to the cap terminal going from 0 volts to full at 12 volts and 1 farad.

My feeble mind thinks the cap may have filled on that first power up before most fuses/ breakers could react.

Tom

[DigitalMind]

Tom, it is a fresh install, and this is the first time ever the outback will be powered on.  Also, they're using a BREAKER that's rated for 400 volts AC.  Just for testing purposes, I had them switch the breaker to the one they're using for their Solar panels (Total of 840 watts) and that didn't make a difference.  

However like you say, if it's got a huge startup current at first, and they've already got the wrong and underrated breaker, I can now see how this could cause trouble.  They ordered the proper fuse from Outback now.  Atleast once they have that if it doesn't still work then we'll know it's not the breaker.  (or fuse depending on what outback is sending them)

[ghurd]

Sounds like what TomW said.

Up for a Mickey Mouse quick fix diagnosis test?

Connect 2 tail light bulbs (ie #1156) in series for 24V.

Connect them to the ends of the breaker.

The bulbs will light up, then go dimmer and dimmer.

Wait 60 seconds after the bulbs go out, but leave them connected.

Flip the breaker.

Remove the bulbs.

Cross you fingers.

It should allow the big caps to charge at a controlled rate so the surge doesn't pop the breaker.

G-

[TomW]

DM;

If they are savvy with wiring they could bridge the braeker with a auto bulb and let it charge thru that. It would limit current inrush. When the bulb dims and goes out it indicates the caps are full, then flip the breaker and it should hold.

Just an idea.

Tom

[DigitalMind]

Haha, you (Tom)  and Ghurd said the same thing at the same time. That's a really cool trick that I will use if I'm ever in that situation !!

Although since I don't REALLY know them all that well, and they're in Spain, i'll keep it safe and have them wait for the real fuse to come in I think.

Thanks so much for all this information !  

[DigitalMind]

I've been helping them with this from afar for a little while now, so I blogged about it recently with pictures that they've taken during the process.  If anyone's interested they're here :

http://www.techienation.com/solarsuno-solar-power-installation-in-spain/

[TomW]

DM;

You are welcome

Careful with the accolades. People might start to think I do more than anger new users around here.

DO NOT tell Glen I agreed with him. It could get messy.

Glad to help.

Tom

[DigitalMind]

Hahahahaahahahahaahahahahahaha,

   That was the funniest comment i've ever read from you Tomw... made my day ... i'm still laughing as i'm typing this.

[s4w2099]

That initial inrush current really stresses capacitors out. What I do to ease it out is to charge the capacitor bank through a resistor at a slower rate. This prevents many possible problems.

The resistor I use is simply a light bulb in series with the battery terminals. Light bulb lights up during high current period and then it starts to go dimmer and dimmer til totally off.

[TomW]

S4;

Well, thats 3 of us with the same method. It must be a good one!

Tom

[ghurd]

Anybody know how to get this last button to work?

http://www.otherpower.com/images/scimages/2050/BanTomW.JPG

Sorry guys, and sorry twice to TomW.  

Way too much time on my hands today.  Busy waiting.

I'll pull it in a day or 2.

G-

[TomW]

Glen;

Go ahead, really. Like our latest irate blocked from posting new user, I got more IP addresses and email accounts than you could ever block.

No harm no foul.

Despite the common theory, I do have a sense of humor just no patience.

I love helping folks with practical advice if I feel I know the answer. The playing security guard is just the punishment for offering to help 6 or 7 years back!  [:=}

Tom

[DigitalMind]

Hahah... Ghurd, VERY funny image.  

TomW, I also have a lack of patience but still like to help, and although sometimes you've come off as harsh, atleast you get your job done.  When I post a message, I can't help but think "Did I research this properly ? Am I giving the appropriate info to go with my question? Should I quote and put links to what I've tried and read BEFORE asking this question?"

Just to make sure I don't make TomW frustrated...    

Thanks again ..  

[wpowokal]

I fired up my Latronics 3000W 24v inverter that had been idle for some weeks and the inrush peak was 37.5A. Now I can't say that the caps were completley discharged but that seems within the capabilities of a load starting rated circuit breaker.

allan down under

[wpowokal]

This afternoon I measured the inrush current of the SEA that I took out of service this morning, it is also 3000 watts, amps were 52. Now this inverter has larger capacitors than the Latronics.

allan down under

[DigitalMind]

Hi Wpowokal,

   Thanks for doing that test !  I guess there's no doubt about it now, that underrated breaker was the issue for sure !

Thanks a lot,

Jason

[dnix71]

I noticed the burglar bars on the front windows. Is this a tough neighborhood?

Also, the solar pv panel doesn't look like it would last long in high winds mounted like that. Is the weather there always tourist perfect?

[richhagen]

My Trace inverter will throw the 150 Amp breaker its attached through if it has been disconnected for a bit.  It is just the inrush of current to the internal capacitance that draws huge current when it is first connected.  Reset the breaker once and mine will then stay on.  You've only got 600 Watts of power to play with through that breaker though, so it might take a bit more to get the capacitors charged up.  





You can see the board with the row of capacitors on it in the middle of the photo.  This was from a 12V version.  It takes a bit of power to get them all charged up.  

[smcardle]

Hi DigitalMind

The tower you see in the picture is a bog standard Spanish electricity pylon. Very ugly and the laws here in Spain allow service providers to install infrastructure on your land (including bus stops!!! I have one of these and an electricity pylon outside my bar and they won't move either).

Here in Spain I am continually surprised by the lack of RE projects for domestic use (and peoples awareness of it), we do have some large wind farms dotted around the country as well as some now very large commercial solar farms. During the summer months of July/August/September we get up to 18 hours of sunshine a day and this with something like 320 days of sunshine a year here on the Costa Blanca makes for perfect solar usage.

We now have a law in Spain that states that every new build must have at least 1 sqm of solar panel installed (not much but a start). This usually is in the form of solar water heating (as in the panel you can see to the top right of the picture on your blog) and rather less usage of solar electricity.

I am new here and new to DIY Solar and Wind power but have been reading veraciously the content on this site and on the Home Grown Power site for several weeks. Right now I am thinking of designing my first wind turbine and have decided I am going to build myself a VAWT (of which particular flavor I have not yet decided but like the look of a couple of designs I have seen here and else where). People say "why not go solar" and I will. But for the pure fun of building a mill from scratch well..... solar panel installation just can't compete.

I look forward to discussing some of my ideas over the coming months with you all and as I progress with my project I will try to keep anybody who may be interested updated.

Steve

[DigitalMind]

That was very educational Steve. Thanks for the info !  It's pretty crazy that they can just go and install these things on private property !!

It's a great thing that they're forcing new buildings to put SOMETHING solar. It's a start !!

Good luck with your future RE projects, I look forward to reading about them here !

Jason

[DigitalMind]

Just to follow up, while waiting for the 200 amp breaker from outback, they went out and bought a 100 amp breaker from a local hardware store (It cost them a small fortune though) so that they KNOW it was the breaker the problem.

With the 100 amp breaker, it powered on just fine and they are now VERY happy.  (Since this was almost the last step of the installation)

They are returning the 100 amp breaker and will not wait for the real outback one.

Once again, a BIG thank you for everyone's help.  It's very appreciated by me, and i'm sure even more from the couple in Spain who is doing this install and somewhat relying on me for long distance tech support.  

[DigitalMind]

Oops, I wrote "will NOT wait for the real outback one" but I meant "will NOW wait for the real outback one"

[la7qz]

Hi

Are those normal wet batteries or sealed (AGM or Gel)? I'm not sure I would want the inverter directly above regular wet cells that are going to gass when they are being charged. The gas is rather corrosive.

(Says the man who lives on a boat and has two T-105 batteries under each of the settees...)

Owen

[veewee77]

Never, ever, under ANY circumstances attemt to use an AC breaker for a DC circuit. They have completely different tripping mechanisms and parameters and if tripped under a load will burn up in a nice blue flame. And the magic smoke will escape.

Very likely a CD breaker will not trip un this circuit.

Doug

[DigitalMind]

Veewee77, I can't help but feel you must be right, but i've read lots of conflicting information about this.  Either way, they ordered the proper breaker from Outback and it's unplugged now while waiting for it.   I personally have never used an AC breaker for DC however.

[DigitalMind]

I have no idea Dnix,

   I'm in Montreal, Quebec, Canada - They're in Spain, I'm helping them by email.  They send me pictures of what they've got along with a description of any problems.   Then I send my best advise back to them.   All in all though, they got it working !! (Gotta love Solar, it's so simple!)