Exploding underground duct bank
This started off as a normal day at a nice hotel. A few guy were installing interlocking brick near the main electrical room’s big air vent, when they heard a big bang sound and saw sparks and flame shooting out of the vent. Soon afterward, the hotel lost all power.After digging a hole and cutting our way into the duct bank, we found the concrete was all hot and black. Almost 12 hours after the big bang, the old conductors were still hot to the touch. The duct bank contained six, 4-in. conduits with up to 750kcmil per conduit.
Best anyone could figure was that a small nick in the wire during installation had boiled the water that was present in the conduit to the point where it melted the insulation off of the other conductors, causing one huge ground fault.(Photo courtesy Michael Kelly of The Electrical Department Co.)
See a good horror lately? Send us your photos of the horrors you’ve seen on the job. Where possible, include a description. Send them to This e-mail address is being protected from spambots. You need JavaScript enabled to view it or by regular mail to:
Anthony Capkun
Electrical Business
House of Horrors
240 Edward Street
Aurora ON L4G 3S9
Featured Video
-
Editor Anthony Capkun sits with Elaine Gerrie, chair of the EFC Foundation Scholarship Committee, to learn more about the over…
Latest Video
-
The Ontario Electrical League is celebrating its 90th anniversary this year. While at OEL’s 2012 Electrical Industry Conference in Ottawa, we chatted with a few electrical contractors, and OEL’s president Stephen Sell, to find out what professionals get out of membership.
-
Thanks to Fluke for sending us this video showing one-handed operation of its thermal imagers with IR-Optiflex and IR-Fusion technology... leaving one hand free to battle industrial ninja assassins. -
May 8, 2012 - Osram Sylvania SSL’s LED expert, Dr. Makarand ‘Chips’ Chipalkatti discusses LED lighting technology, and how this new paradigm is akin to our transition from gas to electric lighting all those decades ago.
comments
RSS feed for comments to this post