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  • #16
    Originally posted by bcroe View Post

    Yes it does, I used one to increase the sensitivity of my early KILL-A-WATT meter before the later ones
    built in better resolution. Bruce Roe
    Based on the amp, volt & wattage readings I would say the CT is working just fine.

    What the OP should know is that before they try to measure the entire solar panel production they should at least know the maximum rating of the CT.

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    • #17
      Originally posted by DanS26 View Post

      A trick I have used to verify small loads is to pass the wire through the CT a few times......then divide the measurement results by the number of windings through the CT. Works like a charm.
      Image A is what I believe you are saying. How about something like image B or image C?

      A.jpgB.jpgC.jpg

      In C, I put the wire through a bunch of washers that could be wrapped in electrical tape.

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      • #18
        Originally posted by Aston72 View Post
        This shows one leg (110 of the 220) of my four panels in full sun.
        The voltage seems correct but the amps should be about 8 (800 watts).
        800 watts / 240 volts would be 3.3A with no losses, nowhere close to 8A. You'd see 3.3A in each leg. They don't add together because they are both part of the same series circuit. But you'll see less than that due to inefficiencies, losses and less than optimum sun. How many/what wattage panels and what make and model of microinverters are you using?
        Last edited by sdold; 07-02-2018, 12:09 AM.

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        • #19
          B & C will work - for something,. but current measurement is not among them.
          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

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          • #20
            Originally posted by Mike90250 View Post
            B & C will work - for something,. but current measurement is not among them.
            Got it. LOL

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            • #21
              Originally posted by sdold View Post
              800 watts / 240 volts would be 3.3A with no losses, nowhere close to 8A. You'd see 3.3A in each leg. They don't add together because they are both part of the same series circuit. But you'll see less than that due to inefficiencies, losses and less than optimum sun. How many/what wattage panels and what make and model of microinverters are you using?
              As I see that now, I should roughly get 3-4 amps each leg.

              My humble setup on my wood shed roof.

              Grape Solar - 265-Watt Polycrystalline Solar Panel

              Enphase Energy Micro Inverter 215W 240/208VAC MC4/H4 Compatible
              shed.jpgenphase.pnggrape-solar.jpg

              field.jpg


              Wired like aboue image. I do not have the envoy.

              EDIT: My location is Concord Area, NH. Shed roof faces south and is 45 degrees.
              Last edited by Aston72; 07-02-2018, 09:59 AM.

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              • #22
                Originally posted by Aston72 View Post

                As I see that now, I should roughly get 3-4 amps each leg.

                My humble setup on my wood shed roof.

                Grape Solar - 265-Watt Polycrystalline Solar Panel

                Enphase Energy Micro Inverter 215W 240/208VAC MC4/H4 Compatible
                shed.jpgenphase.pnggrape-solar.jpg

                field.jpg


                Wired like aboue image. I do not have the envoy.
                OK. Now we see how you have the panels wired, how have you wired your CT and digital meters?

                If you are only measuring one of the 2 legs of that 240volt system you will not necessarily get the correct measurements. You need to measure both legs with separate CT's, volt & watt meters.

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                • #23
                  Originally posted by SunEagle View Post

                  OK. Now we see how you have the panels wired, how have you wired your CT and digital meters?

                  If you are only measuring one of the 2 legs of that 240volt system you will not necessarily get the correct measurements. You need to measure both legs with separate CT's, volt & watt meters.
                  The test meter is wired as in the image. The LOAD in the image is the main house panel. I do intend to use two meters. One for each 120VAC leg.

                  MeterWiring.jpg

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                  • #24
                    Originally posted by Aston72 View Post

                    The test meter is wired as in the image. The LOAD in the image is the main house panel. I do intend to use two meters. One for each 120VAC leg.

                    MeterWiring.jpg
                    Ok. It looks like the max amp input rating of the CT is 100A. So we answered that question.

                    What is a little confusing is this meter is for a single phase load which is usually a hot wire along with a neutral wire yet that diagram does not show which is the Neutral.

                    Since it is also rated for European voltages at 50hz it can accept a single phase voltage of up to 260V where it is common to see about 220V phase to neutral.

                    So my question is which wires are you using for the ones wired to the "load" terminals in that diagram?

                    Comment


                    • #25
                      I don't know if it applies to these, but usually in electronics things are more accurate if they operate somewhere around the middle of the design range. For example you wouldn't use a 0-100A analog meter to measure something around a couple of amps and expect much accuracy. Any chance you could measure this with a clamp-on multimeter and see if it's close? It would be a good excuse to buy that clamp-on meter you might have been wanting

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                      • #26
                        Originally posted by SunEagle View Post

                        So my question is which wires are you using for the ones wired to the "load" terminals in that diagram?
                        The CT is on the black wire (Hot) and the other wire is the white one (neutral).

                        Comment


                        • #27
                          Originally posted by Aston72 View Post

                          The CT is on the black wire (Hot) and the other wire is the white one (neutral).
                          Ok. It looks like you are measuring half of the watts and amps being produced from your panels.

                          I am not totally familiar with those Micro-inverters so they may pass half the amp from each panel on one leg and half on the other. Although the "halfs" may not be exactly equal.

                          I would look into a meter that is set up for 240volt with 2 CT's, one for each leg.

                          Comment


                          • #28
                            Originally posted by Aston72 View Post

                            The CT is on the black wire (Hot) and the other wire is the white one (neutral).
                            But nothing connected to the hot conductors?

                            It looks like there should be two wires to the CT, and two others across the 240. Nothing connected to the neutral.
                            Last edited by sdold; 07-03-2018, 12:49 AM.

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                            • #29
                              Originally posted by sdold View Post

                              But nothing connected to the hot conductors?

                              It looks like there should be two wires to the CT, and two others across the 240. Nothing connected to the neutral.
                              I could be wrong but while that circuit looks like you should connect it to the 240 volt (hot - hot) wires, based on what I read about that meter it is for single phase (hot - neutral) circuits.

                              The reason is shows a max of 260volt input IMO is due to the meter also being good for 50Hz 220volt circuits.

                              Comment


                              • #30
                                Originally posted by SunEagle View Post

                                I could be wrong but while that circuit looks like you should connect it to the 240 volt (hot - hot) wires, based on what I read about that meter it is for single phase (hot - neutral) circuits.

                                The reason is shows a max of 260volt input IMO is due to the meter also being good for 50Hz 220volt circuits.
                                240 hot to hot is still single phase.

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