Author Topic: Too Many Charge Controllers?  (Read 945 times)

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domeguy

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Too Many Charge Controllers?
« on: July 16, 2007, 04:16:14 PM »
I have a Xantrex 4024 wired to a generator to automatically kick in when the batteries get low.  Once the generator starts it wants to finish a full charge cycle. I'm now wiring in a dump load controller (Xantrex C40) that will maintain load on my new Dan-built 10' turbine.  There is also about 1000W (nameplate) of solar connected through another C40 to the batteries in charge control mode.  What happens when the wind picks up after the generator has started and begun the charge cycle?  Will the dump controller prevent the batteries from reaching the required voltage as seen by the inverter?
« Last Edit: July 16, 2007, 04:16:14 PM by (unknown) »

Nando

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Re: Too Many Charge Controllers?
« Reply #1 on: July 16, 2007, 11:03:32 AM »
The Dump controller could give you PAIN .


The way to solve this problem is to do dump control isolation:


Either another diode in series with the wind mill and the dump controller connected at the Anode of this added diode to bring the wind mill voltage below the diode conduction.( a large value capacitor should be there to soften the pulses).


OR place a MosFet with low RDson between the mill and the battery and when when the dump controller operates it loads the mill and at the same time turns of the MosFet.

(ditto for the capacitor)

Of course additional circuitry is needed at the 24 volts supply capable of driving the MosFet fully ON.


Nando

« Last Edit: July 16, 2007, 11:03:32 AM by (unknown) »

domeguy

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Re: Too Many Charge Controllers?
« Reply #2 on: July 16, 2007, 01:04:14 PM »
Thanks for the comments, Nando.  I had thought about putting a solid state relay in series with the dump load with the "coil" driven by the rectified positive wind turbine output on the high side of a series diode.  Until I get that figured out I guess I can turn off the wind turbine when the generator fires up.  I don't intend to leave the turbine going when I'm not there anyway.


-Lee

« Last Edit: July 16, 2007, 01:04:14 PM by (unknown) »

Nando

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Re: Too Many Charge Controllers?
« Reply #3 on: July 16, 2007, 08:22:57 PM »
Lee:


GET a diode with at least 3 times the current and place it in series.


Then at least 1500 microfarads per amp of charging current connected at the anode of the new diode which connects to the DC output of the wind mill, then the ballast connected to that common point of DC out + capacitor + Anode of Diode, this way the C40 dump controller will control the wind mill and not the Gas generator, also, I do not know if this can be done with the C40, and it is to disable the C40 when the gas generator operates.


Nando

« Last Edit: July 16, 2007, 08:22:57 PM by (unknown) »

jmk

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Re: Too Many Charge Controllers?
« Reply #4 on: July 17, 2007, 11:40:44 AM »
 Set all of your C-40 cycle settings so it's higher than what your settings are on the inverter. Then the other controller just a bit higher than that one and you should be dumping only when the gene isn't running and only when your R-E is producing to much. I have the same controls and it works fine as long as your dump load is big enough. Your mill will reach higher rpm at the top of the bulk charge. Your inverter will shut off the gene. The inverter will use all your R-E and less of the gene power as the bulk cycles. If no R-E then it will be all gene. When the cycle is done and you get a lot of wind the inverter will have shut off the gene and the mill will speed up just a bit more to reach the C-40 setting and turn on the dump. The mill will be protected from over speed and the batteries will be protected from over voltage. Your second C-40 needs to be set just a tad higher in voltage than the first one. This voltage setting should be what your battery bank should be figured for, or slightly higher on your second controller. Another thing you need to do is program the rate of charge so it's equal to the size battery bank you have. The inverter will try to throw high amps at the batteries which can over float the batteries and make the voltage appear to be higher than it is and set of the C-40's. Your manual will have a way to figure it out. With four L-16's the max setting is 15 amps of 110. The inverter can push 30 amps on the grid charge mode which I use and not the gene, but if your gene puts out a lot of amps you may need to set that so you don't boil your batteries, and have your dump on while the gene is running. It's an intricate system, but it works excellent! Read and reread your manual. Especially the modes you are using. That inverter manual is long and boring but it's the ticket.  
« Last Edit: July 17, 2007, 11:40:44 AM by (unknown) »