Wiring a diversion load from classic 250

[itri]

Hi,  I've searched the threads and think I know what I need to do, but I'm not sure how to do the wiring.  Background - I'm switching from an old Bergey XL1 charge controller to a Classic 250.  The old controller had a build in dump load function with PWM - when battery voltage got over 28.5, it would start bleeding power to a DC water heater.  It looks like the classic doesn't have this direct wiring option, at least not for the power levels that I might be needing. I can use one of the Classic AUX control functions and run a dump load, but AUX would just control a relay.  So far, so good. What I can't figure out, and need to know if it would work, is how to wire the heater off of the output side of the Classic, and not the batteries. The diagram on midnite's page "classic diversion control, 2 relays" only shows the positive cables, and wiring straight to the batteries which seems strange to me. Thanks for any advice.

[ClassicCrazy]

I think you will find the information you want under this topic - Matrix documented his whole project in detail

http://midniteftp.com/forum/index.php?topic=3881.0

Larry

[FNG]

I would use the Classics Aux2, Feed a DC Solid state relay that feeds the water heater. I would set Aux2 for waste not high with about a -0.5 volt offset. You want to come off the battery positive and negative bus with a proper breaker in the positive and then feed the solid state relay and on to the heater.

[Matrix]

PWM is over my pay grade of understanding for this, but I think (as said above) that it will come off of AUX 2.  Following your project with interest

[Matrix]

Also note,  if you read the link above from Larry,  the reason I ultimately went with AC for the Water Heater diversion thru the inverter rather than battery is for Ultimate Control of power source for hot water.   The way I have it wired,  I can turn of AC grid power from within my house at anytime and heat the water from the grid if there has been no sun or if I have guests over and demand more hot water than what could be produced from renewable energy sources alone.   I would do DC,  but then I would either have to heat from batteries at those times,  or would loss the ability to do so. 

[itri]

Thanks Matrix.  I think the difference between us is that I don't really want or need to heat water, it is truly a dump load when batteries are fully charged but the wind is howling outside.  That's what I liked about my old setup, and why I'm trying to make the new one as dead simple as possible.  Should have explained that better in my first post.

[FNG]

If it is solely for turbine control maybe a clipper would make sense? They work very well for that.

[itri]

Thanks FNG, besides the cost, they are set up for rectification in the clipper.  My turbine does that in the nacelle and I can't change it without spending even more money.

[FNG]

They do have a DC clipper also.

[Highflyer]

Here is a link to the clipper page:

http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=25&productCatName=Wind%20and%20Hydro%20Accessories


They have both AC and DC clippers.