Re: Never push the Big Red Button (New York City subway failure)

[Daniel Seagraves <dseagrav () humancapitaldev com>]

> On Sep 15, 2021, at 10:58 AM, Adam Thompson <athompson () merlin mb ca> wrote:
>
> Now I'm curious... in all of the DCs and COs I've worked in - to the best of my knowledge, I haven't personally 
> tested this! - the EPO button does not​ switch to emergency power.  It turns off ALL equipment power in the space - 
> no lights, no klaxons, nothing.  In simpler setups, the EPO is connected to the UPS so anything plugged in to the UPS 
> does dark instantly.  In one DC I'm familiar with, the EPO switch kills all the UPS output and​ uses several relays 
> to kill commercial power at the same time.
> In some, the room lights were not covered by the EPO switch, in some they were.  Emergency exit lamps will continue 
> to be lit, as they have internal batteries, and are required by building/fire code.

It was always my understanding EPO was to be used for “We have an electrical fire and need to remove the source RFN”, 
not “we need to be on the redundant power instead of city power and don’t want to wait for the automatic transfer”.