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  • #16
    Originally posted by PNW_Steve View Post
    It sounds like you have had to replace relays periodically. Is that correct? What sort of failure are you seeing?
    At first, fairly often, due to being stupid and trying cheap Chinese made garbage. Afterward, due to buying several from a US company, none.

    Paul

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    • #17
      This is the fun, fail safe part of a UL certified transfer switch, if it fails and cooks a lineman, you don't have to go to jail for manslaughter..
      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


      • #18
        Originally posted by Mike90250 View Post
        This is the fun, fail safe part of a UL certified transfer switch, if it fails and cooks a lineman, you don't have to go to jail for manslaughter..
        Not sure I follow your comment, Mike? Steve is looking to buy or build a device, that will switch between mains and inverter, when power fails. If using a relay, it is, quite literally, impossible for both mains / shore power and the inverter to power the receptacles (power points), simultaneously. His original statement regarding this:

        Originally posted by PNW_Steve View Post
        Just to be clear, I want certain receptacles to be fed shore power and when shore power disappears I want them to switch over to inverter power.
        Or, am I missing something in your post? If so, my apologies.

        EDIT: Whenever I had a relay fail, NO power was making it to the receptacles / power points, from either source.
        Paul

        Comment


        • #19
          Originally posted by livingincebu View Post

          Not sure I follow your comment, Mike? Steve is looking to buy or build a device, that will switch between mains and inverter, when power fails. If using a relay, it is, quite literally, impossible for both mains / shore power and the inverter to power the receptacles (power points), simultaneously. His original statement regarding this:



          Or, am I missing something in your post? If so, my apologies.

          EDIT: Whenever I had a relay fail, NO power was making it to the receptacles / power points, from either source.
          Unless you have a fail safe design relays can short out and not isolate a circuit especially if you have a "make before break" program.

          Relays work and DIY can be built but you have to weigh the worst case scenario which could be someone getting electrocuted.

          If the product is made by someone else and has a UL listing the user is pretty much kept out of the lawsuit. If it is a DIY equipment that fails then the user is at fault.

          Comment


          • #20
            Relays can fail 3 ways.
            Contacts all open
            Contacts all shorted/welded
            Some contacts open or shorted. I have seen all these modes, and if you are experiencing failures and need to change relays often, something is WRONG.

            For high currents, contactors are used, like a well pump contactor, they are made to switch heavy loads. you would need 3 of them 2 lines and a Neutral

            My inverter has a built in transfer relay, rated 60A 240V, and contact welding is a common failure mode in my inverter series And they are soldered in. But I'm off-grid and they are not exercised under load, so i expect to be fine.

            But when you start building major electrical components from hobby store parts and they are not UL approved, you are assuming all liability for your actions
            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


            • #21
              I need to preface my reply to let you know I made an error in my previous post, above. I had been awake all night and was exhausted when composing the reply. I stated that:
              EDIT: Whenever I had a relay fail, NO power was making it to the receptacles / power points, from either source.
              That would be impossible. It should have read, "... from one source." I meant no power from the mains. When the relay is energized, it routes power from the mains to the receptacles / appliances. When mains fail, it routes power from the inverter.

              The failures I had after building my ATS units, were the coils. It didn't take me long to sort out the relays I used were junk. When I began using the relays received from the US, that eliminated all of my failures. (The relays I ended up using were probably still Chinese made, but under a western eye?)

              Originally posted by SunEagle View Post
              Unless you have a fail safe design relays can short out and not isolate a circuit especially if you have a "make before break" program.

              Relays work and DIY can be built but you have to weigh the worst case scenario which could be someone getting electrocuted.

              If the product is made by someone else and has a UL listing the user is pretty much kept out of the lawsuit. If it is a DIY equipment that fails then the user is at fault.
              My ATS's are not make-before-break. They are on a farm, where our family and employees are too scared to even touch a 12vdc solar battery, much less anything that is 230vac. UL listings do not exist here. Many pieces of AC hardware are junk, made in Vietnam. Voltage regulators, 230vac plugs, sockets, etc., are junk. Thai made products tend to be of much better quality.

              Originally posted by Mike90250 View Post
              Relays can fail 3 ways.
              Contacts all open
              Contacts all shorted/welded
              Some contacts open or shorted. I have seen all these modes, and if you are experiencing failures and need to change relays often, something is WRONG.

              For high currents, contactors are used, like a well pump contactor, they are made to switch heavy loads. you would need 3 of them 2 lines and a Neutral

              My inverter has a built in transfer relay, rated 60A 240V, and contact welding is a common failure mode in my inverter series And they are soldered in. But I'm off-grid and they are not exercised under load, so i expect to be fine.

              But when you start building major electrical components from hobby store parts and they are not UL approved, you are assuming all liability for your actions
              Living in SEA is a completely different experience than in the west. There is no UL here. Man, this place is closer to the wild west, than it is to modern civilization. Heck, OSHA would have a field day, here. Welding in the rain - using an open cased buzz box, no protection, no eye shield, no gloves, and wearing flip-flops. (No, I wish I were joking.)

              The heaviest draw on an ATS here is a refrigerator / freezer. Frequently, when the mains does fail, the compressor isn't running. (Our other refrigerator has inverter technology. Smooth sailing with it, always.) I am sure, however, we have experienced mains drop outs when it was. I'm actually surprised that I haven't lost the compressor due to that action.

              Regarding relay failures, all were coil related. I've never experienced any contact failures. And, the newer relays (from the states) have never failed. So far, I've been pretty fortunate with their service.

              Incidentally, all mains power here is 230vac / 50hz. It will fluctuate fairly often, as well. Here in the city, it dropped to 178 volts, last evening.
              Paul

              Comment


              • #22
                I think that some are not understanding what I am asking.

                Couple of points:

                A 120v circuit does not need 2 lines and a neutral. Just one line and one neutral.

                The DPDT relay is a break before make device.

                If the relay contacts failed open, shorted or welded in one position I would not energize the incoming line. If shorted it would trip the over current protection.

                ,............ I keep typing and erasing. I am having a hard time finding a way to phrase further questions without starting an argument.

                I'll try again later.

                Comment


                • #23
                  I hear exactly what you are saying, I did not know if your system was single or split phase. if everything works right, it would be fine, and I hope you are happy with it.

                  I was attempting to point out that relays used as a transfer switch, can fail in unexpected ways, such as shorting both poles ( A channel , In to Out) and not simply A to B.
                  As was observed, quality varys wildly.
                  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

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