Articles Tagged with ''troubleshooting and HVACR''

Fractional horsepower permanent split capacitor (PSC) fan motors are one of the most popular single-phase motors used in our industry, and then they fail, technicians must be able to troubleshoot and replace them.

Bob and Tim were at the house of a customer who said that her air conditioning unit did not cool well in the hot weather three days ago. She said the unit actually froze up and had ice on the outdoor portion of the unit on the big line. She shut the unit off and called for service.

As a refrigeration technician, how important is an understanding of basic mathematical relationships? In my opinion, very important. It makes a technician a better technician.

In this month’s troubleshooting situation the equipment that needs servicing is a split system and the refrigerant flow control is handled via an electronic expansion valve (EEV) shown in Figure 1.

Bob and Tim had just arrived at the house of a new customer who explained that the air conditioning system was not working. The homeowner said that they had just had a warm day and the air conditioning system did not come on when they tried to cool the house down yesterday.

A thermostatic expansion valve (TXV) is designed to maintain a specific amount of superheat at the outlet of the evaporator. If the superheat value is too high or too low, the TXV may be the cause. However, before deciding the TXV is defective, all other system causes must first be investigated and ruled out.

Checking temperatures in and out of the air conditioning coil is an important part of preparing a residential air conditioning system for the season. This article will cover how checking temperatures through an evaporator coil can tell a service technician if there’s a problem in the air-handling system or refrigerant system. It will also cover other general troubleshooting areas.

In this troubleshooting situation, the equipment is a split system that’s approximately five years old, consisting of a gas furnace to provide heat in the winter, and a condensing unit and “A” coil to provide summer cooling. There are actually three questions to answer in this problem.

The HVAC industry has seen a significant increase in thermostatic expansion valve (TXV) usage in the past decade. Even though TXVs are the most popular metering devices for residential air conditioning systems, there is still a lack of knowledge about TXV functionality in the market.