I was part of an electrician team renovating a three-letter agency's main data center (adding UPS to an archaic government renovation). As part of this process, we had to isolate the Emergency Power Off system/buttons.
Unfortunately, the EPO ended up having been installed differently than the plans indicated [0] — there was definitely more than an hour of unexpected downtime figuring out how to "unrig" its decades of faithful misconfiguration.
During this same months-long modernization, a separate facility decided to install a temporary tap off our already-temporary taps (no engineering consultation attempted) — with resulting Megawatts of melting disaster. More hours downtime.
tl;dr: shit happens
[0] EPO's main neutral was tied into a general lighting circuit's j-box, some bullshit jerryrigging from an 80s sparkie; our apprentice was tasked with taking out old fluorescents... ended up taking out entire facility (through no fault of his own).
Unfortunately, the EPO ended up having been installed differently than the plans indicated [0] — there was definitely more than an hour of unexpected downtime figuring out how to "unrig" its decades of faithful misconfiguration.
During this same months-long modernization, a separate facility decided to install a temporary tap off our already-temporary taps (no engineering consultation attempted) — with resulting Megawatts of melting disaster. More hours downtime.
tl;dr: shit happens
[0] EPO's main neutral was tied into a general lighting circuit's j-box, some bullshit jerryrigging from an 80s sparkie; our apprentice was tasked with taking out old fluorescents... ended up taking out entire facility (through no fault of his own).