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    Dead SSR or Bed Heater?

    Scheduled Pinned Locked Moved Solved
    Duet Hardware and wiring
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    • Electriceyeundefined
      Electriceye @T3P3Tony
      last edited by Electriceye

      @T3P3Tony

      Resistance is still the same as my original post. I disconnected the leads from the Power supply neutral and SSR and measured them stand alone (not connected to anything else)

      -Resistance check of bed heater leads shows 14.4 ohms (120^2)/1000 = 14.4 ) when checked with multi-meter

      So...how can the resistance be within tolerance or expected levels and the bed still not heat?
      voltages in and out of the SSR all look good still.

      I'm going to go through the wires involved and dbl check connections, but I have done that already once, maybe second time is the charm? I have upped 2 images of the wiring I have done. Not my best work, try not to laugh. 😁
      20250112_154451.jpg 20250112_154502.jpg
      -Cheers!

      1 Reply Last reply Reply Quote 0
      • Electriceyeundefined
        Electriceye @T3P3Tony
        last edited by

        @T3P3Tony

        My FLIR camera doesn't show any obvious issues either.
        Pics of the heater bed are stone cold...as one would expect from a 6.5 mm thick slab of aluminum that isn't heating up. 🙄

        FLIR_20250113_110555_737.jpg FLIR_20250113_105915_588.jpg

        Maestroundefined 1 Reply Last reply Reply Quote 0
        • Maestroundefined
          Maestro @Electriceye
          last edited by Maestro

          @Electriceye If you are confident in doing so, I would bypass/short your SSR and see if the bed heats. BE READY to kill it. Current is clearly not flowing or there would be a kilowatt of energy showing up somewhere. Obviously this is not a solution, but could be diagnostic.

          Electriceyeundefined 1 Reply Last reply Reply Quote 0
          • Phaedruxundefined
            Phaedrux Moderator
            last edited by

            Have you tested your bed output with something like a fan to confirm that it's switching correctly?

            Z-Bot CoreXY Build | Thingiverse Profile

            Electriceyeundefined 1 Reply Last reply Reply Quote 0
            • Electriceyeundefined
              Electriceye @Maestro
              last edited by

              @Maestro

              Yeah, I thought about that and remembered the circuit breaker in this room is only 15A so that would probably trip right away and might not even be enough time to see what, if anything happens.

              Since this is a 120 volt mains bed heater, I'm a bit reluctant to push things too far.
              Without cycling or pulsing the AC to the bed I'd be afraid it would just melt it instantly.

              Oh and I HATE electro shock treatments, they just ruin my day. 😦

              Thanks for the suggestion, though!

              • Cheers!
              Maestroundefined 1 Reply Last reply Reply Quote 0
              • Electriceyeundefined
                Electriceye @Phaedrux
                last edited by

                @Phaedrux

                Now that's an idea... now what to hook up? Would a small appliance type fan rated at 120 volt suffice?
                I have a small ULINE desktop fan I wouldn't mind sacrificing to the AC gods if need be.

                1 Reply Last reply Reply Quote 0
                • Phaedruxundefined
                  Phaedrux Moderator
                  last edited by Phaedrux

                  I'm suggesting you test the Duet output directly, not the SSR outputs. A DC fan that matches your VIN voltage.

                  Though if you're measuring the correct 120v from the SSR output already and it's switching correctly then testing the Duet output is moot.

                  I'd be more inclined to suspect the SSR rather than the heater itself.

                  What are the specs of the SSR? Do you have another to test with?

                  Z-Bot CoreXY Build | Thingiverse Profile

                  Electriceyeundefined 1 Reply Last reply Reply Quote 1
                  • Electriceyeundefined
                    Electriceye @Phaedrux
                    last edited by

                    @Phaedrux

                    Yep. All good points.

                    This leads me back to my original post findings, voltages are there...but that little LED indicator light on the SSR has never turned on, that I have seen. That puts us full circle...is it the bed heater or SSR?

                    Now I'm thinking you are right...it might just be the SSR.

                    I have a new one (different brand) and the bed heater on order already...just have to wait until they arrive. Sigh.

                    jumpedwithbothfeetundefined 1 Reply Last reply Reply Quote 0
                    • Maestroundefined
                      Maestro @Electriceye
                      last edited by

                      @Electriceye A 1000W heater should not trip a 15amp breaker; it only draws about 8.5 amps. If your heater matches your bed mass appropriately it should not be melting instantly, either. Everything is pointing to the SSR not working.

                      But as @Phaedrux notes, you can attach something else to either side of the relay to test function, so long as that something else is rated for the appropriate voltage and won't pull too much current.

                      1 Reply Last reply Reply Quote 1
                      • Phaedruxundefined
                        Phaedrux Moderator
                        last edited by

                        Well in that case it may be a good idea to test the Duet output with a fan, just to ensure it's working properly.

                        For testing the 120v side you could wire up a light socket, but only if you're absolutely comfortable working with 120v.

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                        Electriceyeundefined 1 Reply Last reply Reply Quote 1
                        • Electriceyeundefined
                          Electriceye @Phaedrux
                          last edited by

                          @Phaedrux

                          24 v DC fan works perfectly connected to the 24 volt side of the SSR, turning on and off as commanded by the Duet output.

                          Light bulb test coming up! This is really getting old, many thanks to all for the input & suggestions!

                          1 Reply Last reply Reply Quote 0
                          • jumpedwithbothfeetundefined
                            jumpedwithbothfeet @Electriceye
                            last edited by

                            @Electriceye looking at your picture the input wires on the SSR from the duet are reversed you may want to try reversing the polarity,

                            6HC Voron Trident based, 6XD CNC, Mini 5 polar printer

                            Electriceyeundefined 1 Reply Last reply Reply Quote 4
                            • Electriceyeundefined
                              Electriceye @jumpedwithbothfeet
                              last edited by

                              @jumpedwithbothfeet

                              WINNER WINNER!

                              Fried Chicken dinner! 😁

                              You sir..are correct!
                              The clue I should have guessed was that the LED on the SSR was not illuminating...LEDs are polarity sensitive!

                              The image I was going by (duet3_mini5+_v0.5-v1.02_d1.5_wiring.png) was upside down as viewed on the screen, as opposed to the direction I have it mounted. GREAT CATCH!

                              Board now heats up (quickly I might add) and the LED on the SSR is aglow!

                              jumpedwithbothfeet wins the internets today!

                              Thanks to ALL who had tips, suggestions and input. You people ROCK!

                              1 Reply Last reply Reply Quote 2
                              • Phaedruxundefined Phaedrux marked this topic as a question
                              • Phaedruxundefined Phaedrux has marked this topic as solved
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