Bob has gone on a service call where the customer is complaining that her house is not getting up to temperature. The house was heated with a heat pump with three stages of auxiliary strip heat. Bob removed the panel to the strip heat and found one of the units was not pulling current.
Bob and Btu Buddy have gotten together for a review of their last service call, which involved a control system that Bob was not very familiar with - pneumatic controls. Bob asked, “Why would anyone want to use air as the power source to operate the controls for a building?”
The customer’s complaint on this call was an overall overheating of his building. The manager told Bob, “We arrived this morning and the entire building was hot and keeps getting hotter.” He led Bob to the basement where there was a boiler. Bob found that the system had pneumatic controls.
Bob’s service call yesterday involved a leaking underground refrigerant piping system. Bob replaced the refrigerant lines, leak tested the lines, and left them yesterday afternoon under 150 psig of pressure. He has now returned to the job the next day to see if the pressure held and to check for moisture in the system.
Bob was called to a job that had a no cooling complaint. This was
a new customer and Bob wanted it to be a good experience for the customer. It
was a small stand-alone store building with a 3-ton cooling only unit. Bob determined this was a low charge problem. He installed his gauges and discovered the
unit did not have any refrigerant in it.
The dispatcher called Bob and sent him to a job that really sounded like a problem. There had been a hard rain and a customer had a condensing unit that had been under water that morning due to high water from a creek behind his house. The owners were on a fixed income and wanted to get the repair at the best possible price.
Bob has been on a job at a convention center with a 100-ton water cooled condenser. The owners are anxious for Bob to get the a/c back on, but Bob said the tubes must be cleaned before the unit will run. He has called the shop and asked for a helper and a tube cleaning machine to help him get the unit running as fast as possible.
The dispatcher calls Bob with an urgent service call from the city’s convention center. A convention is going on and the air conditioner is off, and it re-starts but only runs a short time and shuts off again. The maintenance man said he had to reset the high pressure control to get it started. Btu Buddy assists in troubleshooting the system.
Bob and Btu Buddy get together for breakfast to discuss their last service call, which concerned a compressor that had liquid refrigerant flooding back to it. Bob had asked a couple of questions while they were leaving the job. Btu Buddy then proceeds to answer Bob’s questions.
This job is a three-story office building with an air handler on each floor with a refrigerant coil in each air handler. A 75-ton condensing unit serves the three 25-ton air coils. This is an old system that has still been doing a good job. The complaint is that the second floor unit is not holding the conditions that the thermostat is set for.