This article is the second installment of a two-part series. Part One provided some background on screw compressors, then discussed the various components and capacity control methods. Part Two discusses maintenance of the screw compressor.

Screw compressors can be either twin helical screws or a single screw design. They can be open drive, semi-hermetic, or hermetic in configuration. In addition, there are oil-flooded compressors and non-oil (dry) compressors.

Manufacturers purposely design condenser and evaporator coils to work together in order to provide the best possible cooling for an application. So why would anyone consider replacing one coil and not the other? Why would anyone be tempted to oversize or undersize one component when the other isn’t designed for that capacity?

One of the least expensive and most overlooked tests that can be provided during chiller preventive maintenance is oil testing.

Flame rectification is vital knowledge for gas heat troubleshooters. This article deals with flame rectification as it applies to direct spark ignition (DSI) modules.

This article is intended to give you a general overview of piping design considerations and to help you to determine when you might need to take extra measures during an installation.

A clean motor is a happy motor. As any service technician knows from experience, contamination is one of the leading causes of premature motor failure.

When facing a residential oil-fired furnace that is acting up, you want to get the situation under control as quickly as possible. A problem during the heating season will bring a call from an anxious and possibly agitated customer. The following are some of the most common issues that a service contractor addresses when troubleshooting an oil furnace, along with the possible cures.

Many service technicians often become confused when the liquid line becomes restricted in the refrigeration system. This is because the symptoms often look like an undercharge of refrigerant. This article covers a refrigeration system with a restricted liquid line after the receiver using R-134a as the refrigerant. The refrigeration system is a low temperature freezer with a receiver and a TXV.

A simple ohmmeter is all that is needed to troubleshoot a potential relay. After taking all of the connecting wires off of the potential relay, measure the resistance across the 1 and 2 terminals.