Duet3D Logo Duet3D
    • Tags
    • Documentation
    • Order
    • Register
    • Login

    SSR and 220 heated bed. Bed always a 120 volts !!

    Scheduled Pinned Locked Moved
    Duet Hardware and wiring
    5
    8
    1.1k
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • claustroundefined
      claustro
      last edited by

      Hi ,
      Switched from 24 to 220 heated bed.
      Connected following this diagram.
      I don't know if I am making something wrong but if I connect the 220 side to the relay it doesn't respond , the bed start heating and if I measure the tension on terminal 3 and 4 I have 120 volts (!) ( in a 220 power line)
      If I disconnect the 220 side the ssr become controllable , the status led switch on correctly if activated and the resistence in 3 and 4 switch to infinite to almost 0 during activation .
      0_1565106220971_XyYknu7.jpg

      1 Reply Last reply Reply Quote 0
      • dc42undefined
        dc42 administrators
        last edited by

        What make and model of SSR are you using?

        Duet WiFi hardware designer and firmware engineer
        Please do not ask me for Duet support via PM or email, use the forum
        http://www.escher3d.com, https://miscsolutions.wordpress.com

        1 Reply Last reply Reply Quote 0
        • claustroundefined
          claustro
          last edited by claustro

          I am using a chinese unknow brand I had laying around that I bought only for the massive heat dissipator provided with it
          photo attached
          I am waiting for a kudom ksi240 d25 ordered 3 days ago .
          My purpouse was only test connection but at this point maybe will be better wait for the kudom
          0_1565108247029_20190806_181513 (Piccola).jpg

          1 Reply Last reply Reply Quote 0
          • dragonnundefined
            dragonn
            last edited by

            This isn't a AC really, on the label it says 5-220VDC
            So it just will not work with AC mains voltage. It will stay on 100% time and rectifying the voltage (that is why you see 120V on its connection)

            1 Reply Last reply Reply Quote 0
            • claustroundefined
              claustro
              last edited by claustro

              OUCHHHHHH.... I was sure it was ac ...DAMN I am so stupid !!
              I was tricked by the 220 number

              Thank god I didn't made an irreparable mistake!.

              1 Reply Last reply Reply Quote 0
              • nopheadundefined
                nophead
                last edited by

                The label says "5-220 VDC", so It looks like a DC relay to me. Probably a MOSFET which will have a body diode across it which will always conduct when the polarity is reversed. So when off you get half wave rectified mains, when on you will get full AC.

                1 Reply Last reply Reply Quote 0
                • A Former User?
                  A Former User
                  last edited by A Former User

                  If you happen to have a suitable large rectifying bridge you can still use the a dc ssr. place the heater in series with the ac side of the bridge and the ssr across the dc side, making it a controllable short, with the load in series on the ac side. (It will be extra heat to dissipate and probably extra electrical noise as you loose the zero crossing switching, so better to get a proper ac ssr; however in a pinch..)

                  1 Reply Last reply Reply Quote 0
                  • nopheadundefined
                    nophead
                    last edited by

                    Note that 220V AC has a peak of 331V, so you shouldn't really use a 220V DC relay, even with a bridge.

                    1 Reply Last reply Reply Quote 0
                    • First post
                      Last post
                    Unless otherwise noted, all forum content is licensed under CC-BY-SA