trouble with invertor shutdown

[(unknown)]

Just built a Hugh 8ft 12volt generator.First time up 30amps at about 50 mph.Im using a c-4o for my dump load into heater coils & a 1750 watt invertor off a 400 amp battery bank.The controller doesnt send power fast enough too the diversion load when batteries are charged & wind gusts are high.I tried heaver loads & heavier gauge wire to controller but at 15 volts the invertor shuts down.Would a load controller solve the problem?

[TomW]

CN;

I don't think a load controller will do any good since as far as I know they do just the opposite of what you are thinking.

I could be wrong and I am working from memory but the load control functions to cut off the load on low voltage conditions.

Others may have better information.

Cheers.

TomW

[MountainMan]

If the problem is just a transient (like a hundred milliseconds of relay switch bounce in the c-40 or something), then a large capacitor right at the input of the Inverter might do the trick.

If the problem is  just that  you don't have enough load getting switched in by the c-40, then you either need to provide more load, or reduce the genny output.

Does the c-40 have an adjustment for when the load kicks in?  Have you tried setting that a few tenths of a volt lower?

If your alternator is three phase, could  you switch it to the lower voltage of the two different wiring configurations (can never remember if delta or star is lower)?

Them's the only ideas I have.

jp

[MountainMan]

One other idea, can you adjust your furling to make it back off a bit in high winds?

jp

[jimjjnn]

Some inverters have low and high voltage shutdown so you may have to furl your alternator early.

Check your inverter specs or contact the manufacturer for a solution.

[(unknown)]

thanks for the feedback.I like the capacitor idea since it seems like it is just millisecond bursts of power that shuts the invertor off.Does anyone have any ideas on size & where to get one?

[Zix]

Hi North,

It sounds like it's shutting down in over voltage conditions,do you have a dump load? If not that may help you and put the extra power to good use.

Zix-------

[MountainMan]

I'm not sure I want to suggest this, because I would feel a lot safer recommending one with a higher voltage rating, but most car audio places sell large (like 1 farad) caps intended to smooth out the power in ridiculous car stereo installations with multi-killowatt bass amps.  My fear is that if  you went with one of these and your input surged to say 30 volts or something, the cap could explode.  Big electrolytic caps do that when they get too much voltage.  Since you don't have tight control over  your input voltage here, I would steer clear of those.

I guess I would suggest ebay or something.  You would need at least a thousand microfarads I would think with such a low impedance circuit.  I would shoot for something with a 100 volts or more of voltage rating.  It's really a crap shoot unless you can hook up a scope and actually see that there is an "x millisecond" pulse getting past the shunt load controller.

best,

jp

[Nando]

There are other possibilities.

The diversion load can be the problem since the voltage still rises to 15 volts -- tell us the diversion load values --.

The filter capacitor for transient filtering , not more than 100 milliseconds, try around 30,000 Ufd and 25 volts for a 12 V battery.

Of course a greater Ufd value is best and you can parallel them to attain a desired value.

I may not accept a transient voltage as the problem unless there is a high impedance line value.

Nando

[Flux]

Most people except Xantrex seem to know that the C40 is slow to come in and it gives a sensitive inverter time to shut down on overvolts.

I don't know how others get round it but I would have thought the first step would be to set the dump voltage as low as you can get away with to give more headroom.

I am not sure what you do with the capacitors, if you put them across the battery then you will delay the volts to the C40 and keep it waiting longer.

Using thinner than recommended wires to the inverter and a big capacitor across the inverter terminals would solve the high voltage end but may cause trouble when there is no wind and the inverter trips off early on low volt cut out.

In high winds, try to use as much power as possible so that the battery volts rise more slowly.

Flux

[(unknown)]

thank you for all your good comments.I think your right flux about the c-4o being slow.I have had several dealers say they are really designed for the solar market.It should work fine for my load controller.I`ll try getting a capacitor & if that does`t work i`ll use hugh`s design.

[Experimental]

    WOW, I only wish I had your problem -- I can,t get enough wind, because of tall trees around me !!

    I don,t know of any 12 volt inverter, that dosen,t shut down, above 15 volts, and I wonder if you aren,t "cooking", your batteries --- sounds like you need an additional dump load ..

    I built one of "Hugh,s", dual contactor dump controllers -- one contactor, turns on a 300 watt, water heater -- if that dosen,t dump enough, the other contactor, shuts down the mill...

    Also, sounds like your mill might not be furling -- but how often do you get 50 MPH wind !!???

    It also sounds like you have a well deserved --"WELL DONE" comeing, for a very good job on your gen !!

     Best of luck, Bill H.......

[kell]

You can get a 47,000 uF 25 volt computer grade capacitor with screw terminals rated for 85 degrees C at www.bgmicro.com for $2.95

go to their web site and type CAP1115 in their search window.

[(unknown)]

Yes I will need to do some work on my furling.Sure is nice to here from people with the same interests. thanks

[Tom in NH]

If you are using the temperature compensation feature of the C40 and your battery bank gets cold, it could be the controller has raised its float voltage to something higher than 15 volts. If this is the case the solution is to turn down the float voltage adjustment a bit. Alternatively you could move the batteries to a warmer location. The latter is the more difficult solution, but it is also probably the better one because cold reduces the batteries' capacity.

[SparWeb]

I have personally witnessed a capacitor exploding, one that was seemingly sized correctly for the motor.  There is a good reason for induction motors to enclose their caps in a protective cover.  I've also held in my hand those 1 Faraday capacitors from the auto audio stores, and now that I know what I know, I'd never consider putting that in my car.

Voltage spikes could be much higher than you can predict, as others have pointed out.  Please pick a capacitor with the minimum capacitance for the job and the maximum voltage rating you can find, then cover it up with something.

You might also find that a Zener diode could cut off the voltage spikes.  Check with someone who knows more about electronics.