Cat 5 Ampacity
Ethernet cable is a common type of cable - it is CAT 5 or 6 cable. It typically comes in 4 pairs, but is also available in 12 or more.
http://www.sumidacrossing.org/LayoutElectricity/MRRWire/WireAmpacity/ - 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- . Useful chart in terms of differentiating between the number of cores, but does not consider free air vs enclosed
- 23 AWG, .7A - .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
"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.
- 8 conductor, stranded, 22 ga - 
- Cat6, 23 gauge, 19 cents per foot, 300v rating. 
- 22 ga -  exists
- Sourcing - 1000 feet for $200 - 
- 12 pair 22 awg solid exists, but is 10x more expensive than 4 pair - , so 3x more expensive for the same service.
- 22 ga 8 conductor unshielded cable - 
- Belden stranded - 24 cents/foot - 
- 100 feet stranded shielded 8 conductor - $38 - 
- 16 cents per foot, unshielded - 22-8C CMP Plenum -