I am designing a circuit to control a 3 phase resistive load (400V & 30A). The idea is to control the circuit with a microcontroller io. Since it will switch very often (1 Hz aprox), i decided that i am not going to use a mechanical switching relay (it will fail after a time). That is why i am looking for a "semiconductor element" as alternative like a SSR. I have no experience with this kind of applications.

  1. How is this normally done?
  2. Should i use 3 SSRs, 1 for every conductor?
  3. What other elements could i use? which are my alternatives? IGBTs are only for DC current...

Thank you!

  • \$\begingroup\$ Back to back NMOSFETs where the sources are connected together can be used to block current in both directions. The main issue is how to provide a floating gate drive. \$\endgroup\$ – DKNguyen Apr 11 at 22:37
  • 3
    \$\begingroup\$ If you lack experience to design your own solution, use 3 SSRs. They are optically isolated and can be easily driven by an MCU. Remember that AC mains voltage are deadly. \$\endgroup\$ – Jack Creasey Apr 11 at 23:17

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