Inverter overvoltage shutoff

[brianschanafelt]

I have a question about my system. I have my charge control set on 14.20 for bulk and when i get a good gust of wind my turbine goes above 15.0 volts and it makes my inveter shut down due to overvoltage. and when it spikes to 15.0 volts my charge control goes to a red orange overload light. if i disconect one of the heating elements it does fine but still surges to over 15 volts resulting in inverter shutdown

is there something that i am doing wrong!!

NO real information to go on. Probably need more battery for the turbine power but you do not tell us anything we can use to help like turbine wattage battery bank size, Inverter rating, Controller make / model, etc.

[wooferhound]

You need to have a Dump load controller on your battery. It will keep the battery from going over your set voltage.

[Flux]

Not really enough information.

If the surge is momentary and the volts settle back down I suspect that you are using a Xantrec C series controller. These are a bit slow responding, something that Hugh has mentioned often but seems completely unknown to everyone else.

If you have any other controller or the voltage doesn't come back down then there may be other issues that can't be resolved without more details.

Flux

[brianschanafelt]

I have the xantrex c-40 controller. but like you said it takes a while to dump the full current to the dump load. And it is when it spikes really fast that triggers the inverter to overload! But i also don't want to set the bulk below 14.4 so i have a good charge. usually if i have a light on or something that is when it overloads. if i have a more moderate load it does not do it as bad. But i  don't want to have everything running all the time to prevent this.

just had a question thanks for the help i will try to find other ways around this!

[CmeBREW]

I have the same problem with my C-60 which has the dumpload also.  

But with mine it only trips the inverter (Small Xantrex 600W rated/1200 surge) when the batts are fully charged with no load on the inverter at the particular time the mill is at maximum (say around 100watts+ or so).

It will also trip sometimes with only one 20watt load on it.

I suspect the problem is I am only charging two golf cart batteries at a time. (only 220 amp hours total).  

I am still learning myself, but was wondering if it would trip the inverter if I was charging a BIGGER battery bank like 500AH or more??

I can't imagine everyone else having this problem esp/w a whole house set-up. I only have a small system right now.  

I actually have to charge two sets of batteries seperately since one set is older and less voltage after final charge.  I Hook the two sets together at night to watch hours of TV and then disconnect the two sets so I don't sulfate the new batts over time from the old ones dragging them down all the time.

Could probably get a voltage regulator on the mill I guess??

[Flux]

Can't really offer a solution, any self respecting dump regulator would never let this happen. If you have to build something to cure this problem you might as well build your own controller.

The problem is worse with large turbines where the instantaneous increase in power in a gust can be very fast indeed. Even a large battery bank will respond quickly when charged enough to be working in the surface charge region.

Perhaps reduce the absorbtion charge volts a bit and increase the float to compensate.

Flux

[SparWeb]

What's the resistance of your dump load?

At what level of currrent does this happen?

Without an ammeter and a respectable ohm meter you can only guess at this information.

I suspect your dump load does not accept enough current to properly regulate the mill.

Did you test your dump load before hooking it up?

[CmeBREW]

I don't mean to hyjack or anything, but maybe the poster will relate with something that I am doing, since we are both having the same problem.

I just found that there is a discrepancy with the C60 I got and the booklet that came with it. I bought it new, but the book shows the voltage range for Bulk stage from 15-17 volts, but on the circuit board of the C60 it says the range is from 13-15 volts.  

Also, the book says that the float range is 14.5 - 16.5 volts, but the circuit board on the C60 itself says the float range is 12.5 - 14.5 .

I had my Bulk set at 13.5V according to the circuit board itself, and the float at only 12.7v.

But I suspect my main problem is my dump load not being big enough wattage.

For a dump load I have been just using one 12v (200watt) car heater (one element) with a separate fan.  I like doing 'heating experiments'. (200W is about the max of my power generation right now)

  According to my meter, it is 2.4 ohm. Thats higher than I had thought.

Therefore I see what I need to do. Parallel another heating element to get it down to around one ohm.

I suspect the poster may want to do what Flux suggested and reduce the bulk setting down, maybe to 14v and see if that does the trick.  On a windy day, you probably have plenty of extra power going to the dump load anyway.  

What is the watts/ohms and number of elements that you have as a dump load?? Maybe someone can see the problem.

[TomW]

BREW;

Isn't there a test point on the board you can use to read the setting with a voltmeter?

I had one that died and I seem to recall a test point for these settings that you adjust to read 1/2 of the desired setting?

Maybe it was another device but that seems to be how I remember it.

Tom

[CmeBREW]

I just looked at the book again, and found out I mis-read a page. There is no discrepancy with the voltage ranges. I was looking on the wrong page--something about cutting a resister which changes the voltage parameters..Bla,bla,bla.   Sorry about that.  

Yes, Tom, there are points on the pots that I can read the voltage with my digital voltmeter while it is charging. I will do so during the next windy day.

I was thinking, Another possibility with Brian's system problem could be that he may  need to move up to the bigger 60 or even 80 amp charge controller.  I notice that he has a nice 10 footer mill which is probably going way over just 40 amps in a big wind gust.

I'm not sure how those work exactly, but my C60 book says that when an over current trip occurs (orange led I believe) that the controller stays OFF for 6 minutes and then resets.  This is probably when the volts of the batts goes beyond 15 volts during a big gust and trips the inverter off. (which is a pain in beep! I know)

-Just a thought!

[brianschanafelt]

yeah don't cut the resistor!!!! that is for Nicad batteries.

Any way i did a little more investigating last night, It is because i have a few light bulbs in parallel to my elements. reading in a board i came across a posting that said that lights have a much more high current pull until they heat up. so i went and purchased  another heating element. maybe someday i will actually put them in a tank, but not until i move to Colorado in a few weeks. Thanks for all of the postings you all are a huge help

Brian s.

[DanB]

We had a similar problem at Rich's house after we installed his small 7' wind turbine.  He had an inexpensive Xantrex inverter that had a preset (not adjustable) high voltage shut off point.  There is a delay with the C40 (and the C60) and no matter how we set it up, the inverter would shut down in high winds.  Very annoying - the only solution we could come up with was to replace the inverter.  Im not sure if this is exactly your problem, but odds are - if you cannot adjust the high voltage shutoff on the inverter, then I would assume you didn't pay much for the inverter and replacement might be the best solution.

[brianschanafelt]

Do you think that the inverter that i have (Chicago Electric) has a adjustable pot ? and if not what would be a good adjustable inverter that i can purchase.

thanks Dan

[ruddycrazy]

Hi Brian,

         Head on over to Amanda's files and build yourself the LM3914 controller. I made my own and I currently use it on my 350 watt PV 450ah 24 volt array. I leave my 3kw inverter on 24/7 and it's pultry 4 watt idle current draw hardly keeps the batteries from over charging so a simply ni-chrome dumpload dumps around 8 amps and keeps everything in check. Once a month I simply move the dump wire from 27.5 volts to 38 volts for 2-3 days and my 5+ year old agm's are still going strong.

I've forgotten how many people have had problems with commercial charge controllers and in my opnion the DIY approach is always the best way. If your not electronic's savvy I can do a screendump pic showing you how to build one using veroboard.

Cheers Bryan