MidNite Classic 250 Divert Load Wiring - Hydro

[Wingmankelly]

Hello!

I'm new to this forum and would like to apologize up front if this topic has been covered/addressed before. I've looked for any similar articles, but haven't found one that gets at the question I have; which is:

I have a hydro-electric installation that I am installing a divert load into. I've seen other forum topics that suggest wiring the divert load to the battery bus bars, switched using a SSR which is controlled by a properly configured AUX2 on a MidNite Classic controller.

This wiring topology worries me because it seems the batteries would then participate in powering the divert load along with (and potentially at a higher rate than) the MidNite diverting incoming power from the hydro turbine. I'd rather let the batteries power only household loads, while only the power from the turbine powers the divert load.

It seems like a better solution is to divert power coming from the AC/DC rectifier prior to entering the MidNite. In fact I believe this is the solution that the MidNite Clipper product offers. The system I am wiring the divert load into already has a resistive divert load module, so buying and installing Clipper is an expense I don't need.

The attached diagram shows the wiring I am proposing in a very simple manner. Fuses and shutoff breakers are not shown for simplicity sake.

I am looking for input/advice on this wiring topology and any experiences people have had if they've done this. Also, am I missing any pieces in the topology?

Mike

[ClassicCrazy]

I don't have any experience with hydro, but I have experimented with using Aux2 to SSR  to power AC water heater element. Using Waste Not mode with  solar input what it would do is send excess power above the absorb or float  to the load. It does this by pwm the ssr relay and that way would limit the load to always keep the Absorb or Float voltage .
I have also experimented with running a resistive load bypassing the PV input to the resistive load. The pv input was wired in parallel with the controller input . I used a contactor for this and the way it worked would be if the contactor was on all the power went to the resistive load. So batteries full, then power went to resistive load . I didn't have an ssr on that , or the igbt block that I used on my other water heating setup. For this setup I was using a Hawkesbay controller and the aux settings weren't working right in initial firmware for that.
I have a couple videos I made - not sure if they will be of any help to you but I will put the links on here in case you want to take a look at them.
I have a few videos about the hot water system. I used an igbt block to handle the high solar DC input but a few year later after it failed i went to a contactor ( didn't really need pwm at that point )
https://youtu.be/1Vjfv_GMH94
https://youtu.be/s7trVpHLts4
Larry

[ralph day]

No hydro experience either, but I do have a Clipper for my bergey wind turbine.  works great!

Handy when a known wind storm event is coming when trying to sleep.  I can just go to the aux clipper function and turn it "on" until the next morning.

[Wingmankelly]

I don't have any experience with hydro, but I have experimented with using Aux2 to SSR  to power AC water heater element. Using Waste Not mode with  solar input what it would do is send excess power above the absorb or float  to the load. It does this by pwm the ssr relay and that way would limit the load to always keep the Absorb or Float voltage .
I have also experimented with running a resistive load bypassing the PV input to the resistive load. The pv input was wired in parallel with the controller input . I used a contactor for this and the way it worked would be if the contactor was on all the power went to the resistive load. So batteries full, then power went to resistive load . I didn't have an ssr on that , or the igbt block that I used on my other water heating setup. For this setup I was using a Hawkesbay controller and the aux settings weren't working right in initial firmware for that.
I have a couple videos I made - not sure if they will be of any help to you but I will put the links on here in case you want to take a look at them.
I have a few videos about the hot water system. I used an igbt block to handle the high solar DC input but a few year later after it failed i went to a contactor ( didn't really need pwm at that point )
https://youtu.be/1Vjfv_GMH94
https://youtu.be/s7trVpHLts4
Larry

Thanks @classiccrazy!

I dont have an IGBT so will go with the "post controller" divert with an appropruate SSR.

[Wingmankelly]

No hydro experience either, but I do have a Clipper for my bergey wind turbine.  works great!

Handy when a known wind storm event is coming when trying to sleep.  I can just go to the aux clipper function and turn it "on" until the next morning.

Thanks @ralph day!

I dont have a large enough relay to handle the incoming DC coming from the rectifier so Im going to give the post controller/SSR wiring first.

[ClassicCrazy]

If you don't  have to use PWM  and just need on off - consider using a DC contactor.
Larry