Proper wire gauges for extending all CR-10S wires

  • I want to extend all my CR-10S wires. I have two long wire types: 22 and 18 AWG wires. I've done some research and found the following:

    • Extruder heating element: 22 AWG or lower.

    • Extruder thermistor sensor: 22 AWG or lower (Doesn't really need much amp).

    • Fans: 24 AWG or lower (Doesn't really need much amp).

    • Limit switch/filament sensor: 24 AWG or lower (Doesn't really need
      much amp).

    Here is where I've problems determining which wire gauge to use:

    • Stepper motor wires: ?

    • Bed heater wires: ?

    What's the wire gauge needed for the stepper motor and bed heater wires? Obviously, the bed heater needs more amp so I expect lower wire gauge. Is my 18 gauge wire enough for this?

    On the Reprap site, it says that 18 AWG or lower is fine for the heating bed.

  • If my calculations are correct, a typical ceramic heating element for the extruder heating block runs 40 W. At 12 V dc, that equates to 3.33 A. A 24 awg wire is rated for 3.5 A, which means it barely covers the draw from the heater. A high torque Nema 17 motor will draw 2 A (which is probably heavier than most standard stepper motors in most 3D printing applications). Seeing as how the 18 awg wire is rated to 9.5 A, you should have no issue extending your wires using this gauge of wire for all of the extensions.

    Please do note that 3.5 A is @ 75 °C. It is about 2.1 A @ 60 °C. Usually the current is lower than 2 A for steppers.

    Also worth noting that these calculations are for SOLID wires, not stranded wires. Stranded wires can carry less current.

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Content dated before 7/24/2021 11:53 AM