12 KV conductors off their insulators

By Steve McCollum; posted March 29, 2008

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I spotted this a month or so ago, but did not get around to taking a picture until last week (3/15). This is the pole that supports one of the two 12 KV service feeders to one of our office buildings, which also contains a data center.

Note how the crossarm is twisted towards the east, and the tie wires that pulled off are displaced to the east. Either the pole moved or something else caused the wire tension on the east (right) side of this pole to rise enough to warp the crossarm and pull two of the tie wires off.

There are two separate feeders. Each goes to automated throw over switchgear, which can select one or the other in case one fails. Of course, we also have four 500 KVA UPSes to carry our load during switching transients, plus around 4,000 HP worth of Diesel generators in case utility power totally fails.

So, with all that investment in power conditioning and backup, it is unsettling to see two of the three conductors untied from their insulators and simply sitting on the crossarm. It's a good thing that the conductors are insulated!

However, if you look at the original, you'll notice that the crossarm appears to be burned underneath the center conductor.

Later: (3/31/2008) I drove by the pole this morning. The crossarm has been replaced and the conductors are back on their insulators! Thanks to everybody that sent me a note.