Maximum ratings



  • I have read almost the entire of docs site (wiki), but did not find there information about the maximum ratings (except 15A for bed heater).

    What is the maximum allowed amperage for fans (both regulated and always-on), for hotend heaters and what is total input power allowed (all steppers, heaters and fans are ON). What is the maximum allowed amperage for 3.3V and 5V lines for external (relative to Duet board) use?

    Is there any differences in ratings between beta (white) and production (blue) boards?





  • DjDemonD, thank you, I'm experiencing the same problem: I want to connect LEDs through FAN connector 🙂


  • administrators

    Hot end heaters are good to at least 5A and probably capable of more. The combined max total load on the 5V and 3.3V rails is 2A including about 200-300mA for the Duet WiFi itself.



  • 2 x 5A for hotend heaters
    5 x 2A for steppers
    3 x 2A for fans (I'm not taking in account always-on fans)
    1 x 15A for heated bed
    And about ~1A from +12V for 5V and 3.3V rails

    So it is about 40-41 amperes of total power in the worst case.

    Thank you for your answers!


  • administrators

    The steppers take nothing like 2A each from the 12V or 24V rail, more like 0.6A each @12V or 0.3A @ 24V. And normal fans take much less power than 2A each, more like 250mA for 12V axial ones and a bit more for blowers. The Vin terminal block is rated for 32A AFAIR.



  • Yes, I very well understand that.


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