Heated bed 220V vs 24V

  • I like these Manually resetable ones
    0_1554559365178_03236797-531f-4d92-99c4-98c5612996ca-image.png Can be either glued with a thermal adhesive or screwed to the bed itself you could even belt and braces it by using one of these along with a non resettable time of a slightly higher temp onto the heater as Mark has done.

  • @claustro said in Heated bed 220V vs 24V:

    should only the bed grounded if this will be isolated from the frame by V-wheels? I am frightened to not be able to ground all the printer correctly.

    If you have live mains ideally every metallic piece that you may touch should be grounded. This is to ensure if one of the mains wires come loose, or make a short circuit to something the fuse or RCD should fail and protect you from touching something that is live and be electrocuted, or overheat and cause a fire. If the bed moves this becomes more important as it increases the risk of failure.

  • I also use this product on the mains power line, feels safer this way. I think it should trigger even if there is no ground connection (?).


  • Depends on construction, most likely it will have a current transformer across N and L, and any unbalance over the threashold should trigger a fault. However the test button will not work without a ground connection (it needs to send some current to somewhere, ground being the only option).

  • @bearer,that's a good point, but I just tested without ground connection and the test button does shut the power.

    Possibly it simulates unbalance by sending current from L after the current transformer back to N before the current transformer, but I don't know for sure.

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