Yellow = cracked insulator: Red = open conductor

Just after lunch on Friday, the lights started flickering in the office, then all kinds of things shut down. Odd thing was a random half of things didn’t work, but the remainder of things worked fine. The electrician next door makai came over and opened the electrical panel and metered the incoming wires, and one of the legs of the three-phase power was out, so only one half of the box had regular power. There was about 24-volts of leakage current on the dead side, so low-powered items still semi-worked; the emergency lights still detected power and didn’t come on; and inductive things like fans ran, but really slow. We were dead out to the meter, so it was in HECO’s territory. The landscape guys next door mauka also didn’t have three-phase power, so a visual track of the wires coming into the building service entrance led our eyes up to the transformers on the on-property pole and a broken insulator and disconnected contact. Now there’s the problem…

HECO_boom_truckHECO_new_insulatorA dude in a work truck came by and we pointed out the insulator. He said that he had seen several of these in recent days – the bolt inside the insulator corrodes, expands, splits the ceramic, and the circuit opens. Must be all the heat this month exacerbating the stress from the corroded bolts. This repair was more than he had equipment for, so he called in to dispatch. It took until 17:00 for the boom truck to show up, but within a very short period of time, the truck was set up, the protective gear donned, and the insulator replaced and circuit restored.

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