Thanks - Have always color coded equipment and PDU cables (or added 3M colored tape) indicating which bus they are one, and a p-touch label for what it connects to. Considered it a best practice, was wondering if this was codified somewhere.. Cheers! Martin On 11/9/2025 2:12 PM, Christian Liendo via vcf-midatlantic wrote:

I haven't seen anything for A&B power.

Just a note, I worked in multiple data centers and I work in the reserves as a IT and we don't have color codes there either and that's the government where they have a document for everything.

I know we have A&B PDUs labeled and we keep the first numbered power supply to A and the second to B, but that's not a written industry standard. More like it's easier to remember thT way.

On Fri, Nov 7, 2025, 7:17 PM Martin A Flynn via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:

...

When a server or switch has two power supplies, is there a color coding standard for line cords and equipment denoting the "A" power PDU and the "B" power PDU?

Normally would use use red and blue power cables, however looking for an EIA or TIA document confirming this.

Cheers!

Martin