Announcement

Collapse
No announcement yet.

Powering 5A diaphragm pump: Need math help...

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Powering 5A diaphragm pump: Need math help...

    Hello everyone. So far I've been able to set up my system and wiring from watching in the background and stalking post but I've hit a road block.

    I have a 12vDC, 5A, 60w diaphragm pump which is powered from a 120v AC transformer. I need to set up as a misting system for my green house.
    Im lost in trying to calculate the inverter size I would need to accommodate the inrush current of the pump which would intermittent: 20 seconds on, 15min off.

    I have x2, 130Pmax, 17.6Vpmax, 7.39Ipmax panels running in parallel to x2 12v 50ah batteries in parallel. I'm in Hawaii (6-7hrs / day of light)

    I've read a lot about inrush currents killing inverters so I wanted to accommodate for this pump before buying an inverter but I don't know how to calculate for the inrush when it's being fed from:

    12vdc/120vac inverter -> 120vac Transformer -> 12vdc, 60w, 5a pump.

    any help, guidance, or questions to get me thinking and learning would be AMAZING!

    thank you and aloha!

  • #2
    Originally posted by Hawaiiankanak View Post
    Hello everyone. So far I've been able to set up my system and wiring from watching in the background and stalking post but I've hit a road block.

    I have a 12vDC, 5A, 60w diaphragm pump which is powered from a 120v AC transformer. I need to set up as a misting system for my green house.
    Im lost in trying to calculate the inverter size I would need to accommodate the inrush current of the pump which would intermittent: 20 seconds on, 15min off.

    I have x2, 130Pmax, 17.6Vpmax, 7.39Ipmax panels running in parallel to x2 12v 50ah batteries in parallel. I'm in Hawaii (6-7hrs / day of light)

    I've read a lot about inrush currents killing inverters so I wanted to accommodate for this pump before buying an inverter but I don't know how to calculate for the inrush when it's being fed from:

    12vdc/120vac inverter -> 120vac Transformer -> 12vdc, 60w, 5a pump.

    any help, guidance, or questions to get me thinking and learning would be AMAZING!

    thank you and aloha!
    why would you use an inverter if the pump is 12V DC? set up a 12V battery and power the pump directly from it.
    OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

    Comment


    • #3
      Originally posted by ButchDeal View Post

      why would you use an inverter if the pump is 12V DC? set up a 12V battery and power the pump directly from it.
      Thats a great question. I wasnt sure if the current from the battery would damage the pump or not and the pump would need to be controlled by the timer so as not to have it running 24/7.

      Comment


      • #4
        Originally posted by Hawaiiankanak View Post

        Thats a great question. I wasnt sure if the current from the battery would damage the pump or not and the pump would need to be controlled by the timer so as not to have it running 24/7.
        get a DC timer, use a DC fuse for the pump and skip the inverter.
        These pumps. are used in Travel trailers all the time.
        You could even set it up with a relay so that the Charge controller turns it on when the sun is charging so it only runs when there is good solar.
        OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

        Comment


        • #5
          Originally posted by ButchDeal View Post

          get a DC timer, use a DC fuse for the pump and skip the inverter.
          These pumps. are used in Travel trailers all the time.
          You could even set it up with a relay so that the Charge controller turns it on when the sun is charging so it only runs when there is good solar.
          Your post and one search for "DC timers" changed my world. Your knowledge is amazing and thank you for sharing it with me. You're more than a question answerer, you're a life changer. Thanks man.

          Please correct me if my knowledge is off, but would I rate the fuse for the 5a of the pump and place that fuse line side of the battery? Before the timer and pump?

          Comment


          • #6
            Originally posted by ButchDeal View Post

            get a DC timer, use a DC fuse for the pump and skip the inverter.
            These pumps. are used in Travel trailers all the time.
            You could even set it up with a relay so that the Charge controller turns it on when the sun is charging so it only runs when there is good solar.
            could you recommend a good relay to utilize solar power on bright days and battery for cloudy days/night time?

            Comment


            • #7
              Originally posted by Hawaiiankanak View Post

              could you recommend a good relay to utilize solar power on bright days and battery for cloudy days/night time?
              well if you have a minimum time you need to use it then set up a timer that goes off during day time hours.

              If you don't care how much time it goes off then many charge controllers have an option to set up the load port to turn on when charging that you can use to trigger a 5a relay.
              OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

              Comment


              • #8
                Originally posted by ButchDeal View Post

                well if you have a minimum time you need to use it then set up a timer that goes off during day time hours.

                If you don't care how much time it goes off then many charge controllers have an option to set up the load port to turn on when charging that you can use to trigger a 5a relay.
                https://www.amazon.com/Uxcell-a15062...ustrial&sr=1-3

                would this be good option to throw between the charge controller and battery?

                Comment


                • #9
                  I'd use a 10A fuse and use wire rated for 15A (number 14 ga) Saves nuisance blowing of the fuse and the wire is safe Now just worry how often you need to charge brushes in the motor
                  Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                  || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                  || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                  solar: http://tinyurl.com/LMR-Solar
                  gen: http://tinyurl.com/LMR-Lister

                  Comment


                  • #10
                    Originally posted by Mike90250 View Post
                    I'd use a 10A fuse and use wire rated for 15A (number 14 ga) Saves nuisance blowing of the fuse and the wire is safe Now just worry how often you need to charge brushes in the motor
                    Ok, great advice ty.
                    So the setup would look like:

                    battery -> 10a fuse -> 12vdc timer -> diaphragm pump ?

                    Comment


                    • #11
                      That's how I'd do it. Will the pump need to run much at night ? That will set the size of the batteries and the size of the batteries requires some certain size of PV array to recharge and power things..
                      Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                      || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                      || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                      solar: http://tinyurl.com/LMR-Solar
                      gen: http://tinyurl.com/LMR-Lister

                      Comment


                      • #12
                        Originally posted by Mike90250 View Post
                        That's how I'd do it. Will the pump need to run much at night ? That will set the size of the batteries and the size of the batteries requires some certain size of PV array to recharge and power things..
                        It doesn't have too, but I couldn't find a controller that can set time chunks of "off"

                        do so you know how or if a relay would help in this case?

                        Comment

                        Working...
                        X