# Cat 5 Ampacity

## Contents

# Introduction

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)

Also: https://en.wikipedia.org/wiki/American_wire_gauge

# Charts

- 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

# Notes

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.

# Sourcing

**8 conductor, stranded, 22 ga**- [3]- Cat6, 23 gauge, 19 cents per foot, 300v rating. [4]
- 22 ga - [5] exists
- Sourcing - 1000 feet for $200 - [6]
**12 pair 22 awg solid exists**, but is 10x more expensive than 4 pair - [7], so 3x more expensive for the same service.- 22 ga 8 conductor unshielded cable - [8]
- Belden stranded - 24 cents/foot - [9]
- 100 feet stranded shielded 8 conductor - $38 - [10]
- 16 cents per foot, unshielded - 22-8C CMP Plenum - [11]