CONTROLLER ?

[2windy]

I think I am a little confused about the diversion load control on my new C-40. I've read the manual over several times but I can't seem to get it. It says it diverts all the power from the source [the source is my wind genny]to a dump load. When I look at the wiring diagram to hook it up I just see the power from the genny to the battery bank from there then to the controller. My bank is 12 volt, my genny is doing 30 to 40 volts 10 to 20 amps. I've talked about a dump load here before but is the controller just draining my batteries when I get charged above 14.5 volts or is this really diverting the 30 plus volts from my genny to the dump load? From the wiring diagram that came with it it looks to me that it is just unloading the batteries when they get full, so that means that I would only be putting 12 volts to my dump load. Is this correct?

[SamoaPower]

First, let me assure you that your C40 is NOT dumping battery power. I think what might be confusing your understanding of the diversion load configuration is that you're thinking in terms of voltage rather than current when it comes to what is being diverted. During the bulk charge phase, all the available source current is going directly to the battery which will slowly bring up it's terminal voltage. Nothing is being diverted at this point. Upon reaching the bulk voltage set point, the controller switches to the acceptance phase and starts diverting a portion of the source current to the dump load to maintain the battery voltage at this point. If diversion did not happen, the battery voltage would continue to rise. The diverted current only comes from the source, not from the battery. If the source should stop delivering current at this point (wind dies), the battery voltage would start to drop and diversion would immediately cease. The same process goes on during the float phase but at a lower set point.

[Flux]

I have never used the C40 but I believe it can be used in 2 modes. For solar it would open circuit the panels when the battery voltage is high. This is what I think you mean when you say disconnect.

You must not use it in this mode for wind. The alternator voltage will rise to a high value and damage the controller and the alternator will over speed become noisy and may be damaged.  When connected to the battery your alternator will not produce the sort of voltage you mention, but without a controller will slowly drag the battery volts up to nearly 16v and they will gas violently. You must use it in diversion mode, where it diverts excess power to a dump load when the battery has reached a preset voltage.

SamoaPower has explained the operation of the controller in diversion mode. Just check that you use it in this mode.

Flux

[Spelljammer]

This is a comment I made on another post a few weeks ago......

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Imagine that your windmill is trying to put out 50 volts at 28 mph wind and the battery is at 14.4 volts and rising.  Your controller switches to a dump load of 12 volt water heaters.  Now those water heaters are 600 watts each at 12 volts, but now they are using 50 volts.  They quickly heat up using that 2500 watts of power and burn up.  Now you have an open circuit, no load on the windmill, and batteries are full...oops.  Windmill shoots up to 600 rpm and splat.

The better way to do it is to use the dump load controller to run a relay or selenoid switch that connects to the battery bank.  That way you only have a few amps through the controller circuit and a lot more amps coming from the battery through the relay or selenoid switch going to the 12 volt heater element or other load.  And the best part is that the heater element will run at its intended voltage instead of some huge voltage directly off the alternator.

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Here is a website that has one for sale.  They don't deliver to Canada though.

http://www.hydrogenappliances.com/batteryregulator.html#anchor7951238

[Flux]

As far as I know, when in diversion mode the C40 does not change the load over to a dump resistor and let the mill run riot into it. I think it just diverts excess current at the regulating volts.

Even if I am wrong about the operation of the C40 and I must confess to have never used one, your logic about the power into the heaters is wrong but I will not confuse things by going into that.

Flux

[kenputer]

Hi spelljammer, you can get one of the SEA50 50 amp dump load regulators from Survival Unlimited they shipped me one here in nova Scotia.

Ken

[SamoaPower]

Yes Flux, you have it correct except that the C40 actually has three possible modes with the third one being load control (undervoltage load disconnect), which isn't important to this issue. It's interesting to note that no changes are necessary to the C40 to have it run in either series control or diversion mode, it's only how the system is interconnected. Diversion is by PWM and although rated at 40 amps, it doesn't overcurrent protect until 85 amps. I suspect it can be run at considerably more than 40 amps if heat sink cooling is provided (small fan). The heat sink is rather small.

I run one in diversion mode for a combined solar and wind system. I see no sense in throwing away excess energy from either source if you can put it to good use. In my case, the dump load is a mini air conditioner made from TEM's (Thermal Electric Modules) which will sink about 50 amps. I certainly don't need additional heat here in the tropics.

[2windy]

When I get home from work I will try to copy the page out of the manual and post it here.  I think from the wiring diagram Flux is correct.

[Ungrounded Lightning Rod]

I don't know what it IS doing.

But what it SHOULD be doing is pulling current from the battery when the battery is overvoltage.

And it should pull MORE current than the mill can produce at the windspeed where its output is maximum.  Otherwise a wind near the magic speed will overcharge your batteries.  (When the battery gets back down to or below the setpoint, the controller can turn the load off again.)

Think of the battery as a reservoir, the genny as a river running into it, the dump load as a spillway running out of it, somewhere below the top of the dam, and the voltage as the water level.  You don't care WHICH molecules of water go in and which go out, or whether the spillway is near the river or on the opposite side of the reservoir.  Once the dam reaches rated capacity you just want the spillway to dump water AT LEAST as fast as the river can deliver it, to keep the dam from breaking.

Of course "at least as fast" means "faster", since you can't hit it dead on and "slower" means "dam breaks".

[DanB]

I think its been fairly well described allready but maybe its still confusing (it seems that way to me).

There is a jumper there that you move to switch it to 'diversion controller' (or something like that) and then the C40 sits between your batteries and a load of some type (a heater normally).  Your heater should probably not draw much more than 40 amps @ 12 volts (If you have 12V batteries) or you might cook the C40 (I cooked one with a 60 amp heater which was still too small for my incoming power a couple years ago) - the thermal shutdown did not save mine.  If your system can put more than 40 amps into your batteries then you need a bigger regulator and a bigger heater - or - I think you can use multiple C40's.  12 volts is a pain and gets expensive when you start having to handle much current.

[2windy]

The diagram is in my files

[2windy]

[SamoaPower]

No Dan, there's no switches or jumpers to change from series mode to diversion mode. It's all in the way it's interconnected. There is a change necessary if you want to use it in the load control mode. A small fan on the heat sink can extend it's capabilities.