Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm trying to clean up a rackmount power environment, and wanted to check on the power cords. Currently, it seems that what I would consider to be appropriate are labeled mostly as 14AWG:

  • 14AWGX3C
  • 3X14AWG

Some are labeled as 18AWG, though most I wouldn't want to put on a rackmount server power supply:

  • 3X18AWG
  • 18AWGX3C
  • 3C/18AWG

The questions I have are: which ones are appropriate for rackmount servers? What does the labeling mean? Should I remove all 18AWG cords from the racks?

If you want some specifics, the servers are all Dells and include (PowerEdge) server models like these: 2950s; r710s; 2850; 2650; 1850; 1650...

share|improve this question

AWG is the American Wire Gauge standard. It categorizes the an electrical cable by the thickness of the conductors. Generally, the lower the number the thicker the cable, and the more amperage (power) the it can carry.

If your power supplies do not need to draw more than 14A, then your 18AWG cables are fine. If they need to draw 20-25A, then you should replace them with 14AWG cables.

If you are using the cables that Dell shipped with your server, then you're fine.

share|improve this answer
I suspect that many of these cables are not what was shipped with the servers - thus the question... – Mei Nov 11 '11 at 21:07
@David Ok, so then you're going to need to look at the servers in question and see what they should have based on my answer. Or, you could just play everything safe and use 14AWG everywhere. I don't think I've seen a server need anything heftier than 14. – MDMarra Nov 11 '11 at 21:09
Also: the AWG description is easy; what does the rest of it mean? Some of the 18AWG cables look very lightweight, and some do not. What does 3X mean, or X3C or 3C? – Mei Nov 11 '11 at 21:09
@David That's three different ways of saying that it's a standard 3 conductor cable. If they are built to spec, the "feel" of the cable shouldn't matter, but - like everything else - there are poorly manufactured cables. They're cheap enough that if you're unsure, you should toss it. – MDMarra Nov 11 '11 at 21:11
"3C" = "Three Conductors"; the "X" = "each/by" (like in 4x4). So a "14AWGX3C" can be read "14 American Wire Guage, 3 Conductors". Note that American wire specs do not include ground, where IEC do. Computer power cables should say "3" or "3C" to indicate they have Hot, Neutral, and Ground. In the US, building wiring is typically 2C+G (for the same Hot, Neutral, and Ground). – Chris S Nov 11 '11 at 21:32

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.