[RE-wrenches] off-grid pump controls

[mick abraham]

Bruce @ Medocino Solar asked about "the best control strategy" for making a pump run only after the battery completes its absorption phase.

Mick says: The Morningstar Relay Driver might help. It seems very versatile but also a bit tricky to figure out. One must really think like a controls whiz...which I guess I'm not. If the company would write some good wizard type computer software, that would help. There is some free Windows software for sending the instructions, but not much help for figuring out what instructions to send in order to achieve a certain set of operations.

For this application, one channel could be set up to "receive or not receive 12v" from the MX-60, and another channel could be set to trigger the actual pump closure relay in response to that while adding a minimum running duration, for one example. It's also possible to use two channels in series with the relay coil, both of which would have to be satisfied before the coil would get power.

If the Outback 12v were set to show up when the MX goes into float, then the Relay Driver maintains energy on your pump relay coil until the battery voltage drops back to 26 volts (assuming 24 volt nominal)...an arrangement like this would make the pump run until the sun goes down. Nice idea and I think that could be set up, but...

...too bad I don't speak the language of Boolean logic better because I suspect the Relay Driver product has many more possible applications than I can grasp. Perhaps others could chime in, or be sure to post your results on-List if you try this item.

The instruction manual can be downloaded from www.morningstarcorp.com   Consider doing that for step one...

Mick Abraham, Proprietor 
www.abrahamsolar.com 
Voice: 970-731-4675

 
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