The dispatcher notifies Bob that a motel owner has called and said that the 50-ton chiller that serves his motel is shutting off and the high-pressure control must be reset to get it to run again. Then it will only run for a short while and shut off again.
Bob arrives at the job with a little doubt in his mind because it is a strange job to him and he has never worked on a water-cooled unit. He has been thinking on the way to the job what he should do first. Since it is shutting down because of high pressure, he knows that he should check the part of the system that rejects heat, the cooling tower.