Re: [RE-wrenches] Pump control

[Allan Sindelar]

Mac, No, I haven't done it, so take this with a grain of salt... Here's a simple mechanical approach: have you considered a dual-action float switch on the PV input to the CU200? Check out SJE Rhombus at http://www.sjerhombus.com/products/product_info.asp?id=330. This three-wire mechanical float switch has a common wire, a pump-up and a pump-down wire. You could wire the PV input to the common, the pump-up to the CU200 PV input (NOT the float switch terminals), and the pump-down to the charge controller. I see one problem that you might not have considered. The SQF needs at least 30V to operate, is pretty happy around 65V (4 old 12V modules), but likes 90-120V best. It will take a pretty expensive controller, like an FM60, to accept input voltage that high. In in Haiti's hot climate there's little benefit from MPPT. You might consider a helical-rotor pump that operates at lower voltage, like a Sunrotor. Allan   Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Positive Energy, Inc. 3201 Calle Marie Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com On 12/14/2011 8:40 PM, mac Lewis wrote: Wrenches, wrenchers and wrenchees, I've got a pump control question.  Working on a stand-alone pumping station in Haiti.  I am planning on using a Grundfos SQflex pumping system with a Cu 200 and a float switch.  Also needed on site, is a small pressure pump to force water through a purification system.  This part won't take much power, and the cistern will sit full most of the time, so I'd like to be able to take advantage of this.  I am thinking that I would like to figure out a control system that works off of the float switch that when the float is up, the array leads disconnect from the pumping system and connect to a charge controller that charges up some batteries that will be used to power the pressure pump. Has anyone designed anything like this?  Any ideas on how to do this?  I think I can use an op amp to amplify the 15 mA signal on the float switch to push a relay, but that may not be as reliable as it should be. Thanks in advance. Mac Lewis -- Mac Lewis "Yo solo sé que no sé nada." -Sócrates _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org

_______________________________________________
List sponsored by Home Power magazine

List Address: RE-wrenches@lists.re-wrenches.org

Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out participant bios:
www.members.re-wrenches.org