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

Sean Donelan sean at donelan.com
Fri Sep 17 13:59:28 UTC 2021


Sigh, people often mis-hear this when I say it, so I will try to say it 
carefully.


If you have an Emergency Power Off (EPO), the electrical code (and 
life-safety code) allows use of several alternative wiring methods. Some 
people mistakenly believe the allowed alternatives are the rule, but they 
are actually exceptions.

On the other hand....

If you do NOT have an Emergency Power Off (EPO), you are NOT allowed to 
use the associated alternatives in the electrical code. Among the 
alternatives NOT allowed without the EPO, is almost everything in 
Article 645 -  Information Technology Equipment rooms (or the equivalent 
in international electrical codes). Most people, including licensed 
electricians, believe it is the other way around.

Why does Article 645 exist? (and equivalents in other international 
electrical codes)

IBM in the 1950s published construction specifications for Automatic Data 
Processing rooms for its mainframe computers, which everyone else copied. 
IBM wanted to use alternative wiring methods in ADP rooms for its 
mainframe computers, so the Big Red Button was born. Also, mainframe 
computers used to cost more than the building, so people (insurance 
companies) didn't want the mainframe damaged during a fire.

It is possible to design a data center WITHOUT using those electrical 
code exceptions, and WITHOUT a "Big Red Button."


You can check, because my data center ideas were copied by several 
tech companies world-wide (you know who you are), and don't have Big Red 
Buttons. All of those data centers also have water-based automatic fire 
sprinklers. Both were very radical ideas at the time, which are now 
commonly accepted.


In most cases, you'll need a fully licensed, Professional Engineer 
specializing in Electrical Engineering to sign off on the final design. 
A licensed electrician isn't enough.  Nevertheless, it is possible to 
build a safe, code-compliant data center WITHOUT a Big Red Button. The 
design also seemed to be more reliable.


Let the misinterpretation begin ...


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