Last week I got the chance to sneak out of the office for a few hours to visit and report on the 2011 UA Apprentice Competition. Held in Ann Arbor, Mich., it is an intense contest designed to test the skills of UA apprentices.

In this troubleshooting situation, the equipment you’re servicing is a 240-volt, single-phase split system in a small office, and the customer’s complaint is that the system is blowing warm air.

Bob and Tim are on the second day of an inspection of an apartment house building that has multiple split-system heat pumps. They have inspected all 60 outdoor units on the roof. They are now going to inspect the indoor units.

Tools are so important these days that when Milwaukee Electric Tool Co. held its fourth annual symposium for products used in its core markets of electrical, plumbing, remodeling, and HVAC, it attracted 50 plus trade press from seven countries.

The problem in this scenario is a restricted liquid line after the receiver. Where do you go from here?

Bob and Tim have arrived at the apartment house that they have been working at for the last several days. They’ve gone to the roof where the outdoor units are located. There are 60 heat pumps that use R-22 as the refrigerant. They start with Unit No. 2.

In this situation we have a customer who has called for service on their gas furnace, and the description of the problem is “no heat at all.” The customer also reports that this is the first time they’ve had to call for service on their 10-year-old unit.

Many servicemen experience service calls where the compressor has both a low head pressure and a high suction pressure. There are three main reasons why a compressor will simultaneously have a low head pressure and a high suction pressure.

Bob and Tim have arrived back at the apartment building where they have been working for several days inspecting and making necessary repairs to the building’s split-system heat pumps. Bob said, “Check the list for another unit that seemed to have a problem and let’s take a closer look at it.”

Megohmmeters (meggers) are electrical meters used to check the resistance and condition of the motor windings and the condition of the refrigeration and oil environment around the motor windings. A megger is nothing but a giant ohmmeter that creates a very large dc voltage (usually 500 volts dc) from its internal battery.