[c-nsp] 7609 6000W-DC PWR supply cabling Question

[Doug McIntyre]

On Mon, Mar 31, 2008 at 01:39:31PM +0200, William Jackson wrote:
> The 6000W-DC power supply takes four pairs of 4AWG PWR cables, my
> question is the following.
> 
> Which way is this setup cabled?
> 
> 1.	all 4 pairs of cables going back to a single circuit breaker of
> ( 6000/48 = 125Amp )
> 2.	each pair of cables going back to a separate circuit breaker of
> ( 6000/4 = 1500/48 = 31.25 Amp )


Each pair would go back to a seperate breaker. If you are expecting
a max draw of 31.25A, you'll need a 40A breaker on each.

You'd be able to get away with 5AWG, but 4AWG is probably more commonly found.

Typically, you are feeding the rack with an A and B power feed anyway,
but in this case, the tech note in the installation manual says you
need to feed all 4 pairs for each from the same feed, so one PEM from
A feed, and the other PEM from the B feed.

I guess Cisco just didn't feel like requiring 00AWG cable from its
customers or whatever is needed to handle it in one shot for this beast.