Cat 5 Ampacity

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Jump to: navigation, search - says AWG 24 carries 3.5A open and 2A enclosed.

From Stefan H

Under the following assumptions up to 3A should be fine.

- 26AWG cat5/6 cable

- using two leads

- cable is relatively short

- normal ambient temps

- stepper control (at most use 75% of configured drive current)



  • This chart suggests about 1.8A for 8 core wire 23 AWG- [1]. Useful chart in terms of differentiating between the number of cores, but does not consider free air vs enclosed
  • 23 AWG, .7A - [2].Why the 100% difference betweeen different charts?
  • This chart shows free air and derating for bundles, which most approximates open air Cat 5 (8 bundle) - here 23 AWG is 7A*.7 = 5A


Change on CEB controller: using RJ45 for power-over-cat5. That is a great standard for easy connection, as 8 leads are rated for a total of 16 amps enclosed, and 28 Amps open. So a good product ecology standard for all electrical signal/power transmission in CNC and controls applications. The relevance is the cost and easy connection in prototyping.

We could potentially even consider power over cat 5 for scalable power supplies - such as 8 cat 5 wires get you to a 200A welder - which would be the first use I hear of power electronics over cat 5. I think it's worthwhile because cat 5 is ubiquitously available. Phone burial feeder cable can also be used with Cat 5 ends, no?cc

From Oliver

"Each pair of twisted pairs will need to handle a current of up to 600 mA (Type 3) or 960 mA (Type 4)."

Thats what a pair can handle (in the new upcoming 4PPoE standard), means per wire about 300 mA to 480 mA.


  • Cat6, 23 gauge, 19 cents per foot, 300v rating. [3]