SSR for 24v heat bed

  • Hiya i have the following heat bed, Hictop 275x220 24v
    whats the best SSR for this kind of heat bed

    The reason is to ensure safety and not allow the house to burn down.

    Kind Regards

    HICTOP 275 x 220mm MK3 Aluminum Hot Bed PCB Heatbed Platform for Reprap 3D Printer 250W 24V + Wiring

  • you don't need an SSR, you can connect this bed safely to the duet (given that you have a PSU that can deliver that load)
    a 24v 400W PSU would be ideal, for example the one you can find here:

  • Iv got a 24v 350w 14.6A would that be enough to cover the heatbed,
    and two E3D v6, titan extruders

  • two extruders eventually

  • administrators

    That PSU should be adequate for a single hot end, but it's bit light for 2 hot ends.

  • thanks

  • If you want to switch heavy dc loads off the duet board or use a second psu for the bed, consider an external mosfet unit search ebay/Ali, there two types one looks capable of 50+ amps no problem and they're $5-10.

    I'm using the smaller sized one to control a 24v heated bed off a second psu and at 12.5amps it barely get warm.

  • Agree with MOSFET vs SSR for heating with DC (12V or 24V). Most of the SSR failures I've heard about are from people using them with DC supplies. I believe that is because some (all?) SSRs are designed to switch power at the zero-crossing of an AC power-source, so there is no current flow during the switch, which eliminates power dissipation during the switching time. The SSR on my SSR-controlled 400W / 120VAC bed is always cool to the touch, whereas I've read that ones switching DC get warm/hot and need a real heatsink.

    So yeah, MOSFET for DC.

  • administrators

    For SSR advice and recommendations, see There are some good DC-DC SSRs available, as well as awful ones.


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