HP server Power Supply Cable??

There's a HP server my work got from a company that went bust, and I wanted to test it out.

So I go to plug it in, but the power cable I tried didn't fit.

It turns out there is a nub in the power supply connector so I can't plug in a regular power cable.

Has anyone ever heard of this and know where I can purchase a power cable?

The server is huge and even has wheels.

You may have to take a look at the Server section of eBay. There are always a lot of HP parts, accessories and components for sale there. Only thing, I've never seen an oddshaped power cable for an HP like you describe. This might be a case where the PSU could be damaged in some way.

No it definitely isn't damaged because this thing has 3 power supplies and all 3 are the same.

They look like hot swappable power supplies too.

Got any pictures???