Unalaska has had numerous power outages over the last month, but the latest one isn’t related to the previous ones.

Public Utilities Director Dan Winters says yesterday’s noontime outage was caused by a gasket failure in the cooling system. The water drained out of one of the Wartsilla engines, triggering an automatic shutoff. Winters says they started another engine to pick up the dropped load while replacing the gasket.

The rolling outages of two weeks ago were caused by a different system failure. Winters says the city has traced that problem back to the electronic control system on the CAT C280 engine.

Winters says there’s a glitch in the programming that’s causing the engine to suddenly slow down, which in turn triggers an automatic shutoff. He says local CAT technicians and personnel are still working on a fix to that problem.