Bob and Btu Buddy were on a service call yesterday where the compressor motor was running overloaded due to internal load; the bearings were dragging or worn. Btu Buddy told Bob, “Motor overload protection and circuit protection are subjects that need to be discussed later.” They’ve gotten together today for that discussion.
In this month’s troubleshooting situation, our customer has called to say that the older package unit that heats and cools his office is managing to warm up the area, but then seems to cool down too much before providing heat again. When you arrive, the first thing you note is that the indoor blower motor is operating, and you check the fan switch setting on the thermostat.
Bob got a call from the dispatcher to go to an office building that has a 3-ton heat pump compressor that has been shutting off after startup. The fan would continue to run. The building maintenance man said that he had observed the shutting down of the compressor several times.
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.
This troubleshooting situation is a look ahead to the upcoming cooling season. Our customer has called to say that their heat pump “isn’t cooling at all,” and while the outdoor temperature is only in the mid 80’s, it’s quite uncomfortable in the house. You find that the underlying reason is that the compressor and outdoor fan motor aren’t operating.
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?”
Effective pump maintenance allows industrial plants and commercial facilities to keep pumps operating well, to detect problems in time to schedule repairs, and to avoid early pump failures. Regular maintenance also reveals deteriorations in efficiency and capacity, which can occur long before a pump fails.
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.
When the customer calls for service, he tells you that when things got very cold in the house, he disconnected the power supply to the unit, and then, after turning the 120-volt service switch back on, the operation seemed normal and the house got warm “for a day or so.” But the failure repeated.