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

Jay R. Ashworth jra at baylink.com
Wed Sep 15 18:54:23 UTC 2021


----- Original Message -----
> From: "Adam Thompson" <athompson at merlin.mb.ca>

> 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.
> 
> Is it (somewhat) common for an EPO switch to only disconnect commercial power
> and leave local redundant power live?  What sort of facilities would have this?

No... I just hadn't had my coffee yet that morning and I crossed the streams.

That should be the response to the *ATS cutover*, not the Molly switch.

If someone hits the Molly button, you don't *need* an alarm.  :-}

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       jra at baylink.com
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates       http://www.bcp38.info          2000 Land Rover DII
St Petersburg FL USA      BCP38: Ask For It By Name!           +1 727 647 1274


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