A number of recent unplanned power outages in Unalaska were caused by an electronic governor — located on one of the city's diesel engines — that needs retuning, according to city officials.
Public Utilities Director Dan Winters said at a City Council meeting Tuesday night that what's supposed to happen is that when the engine is shutting down it comes down automatically, at about 1000 kilowatts and then it will open the breaker. But it's currently shutting down at more than twice that amount — at about 2500 kilowatts — and kicking the breaker.
"It's too much load for the other machine to catch all at once like that," Winters said. "Our fuel breakers are designed to open up on any hertz that drop below a certain amount per certain amount of time — [at its current rate] that breaker will open up, and that's what's happening."
Winters said someone locally is looking at the equipment and that they are in contact with the manufacturer to reprogram the electronic governor.
"Both of those Wärtsilä [engines] were overhauled, and it so happens to be that the governor that is giving us trouble was replaced. And we are looking into that. It should be under warranty," Winters said.
Winters did not say whether or not the city would need to purchase new equipment.
He did not respond to multiple requests for further information.