What is a common issue if the head pressure is excessively high?

When the head pressure in an ammonia refrigeration system is excessively high, a common issue is a decrease in compressor efficiency. High head pressure indicates that the compressor is working harder to move the refrigerant through the system due to increased resistance from the discharge side. As a result, the compressor requires more energy to compress the refrigerant, leading to reduced efficiency in its operation. The compressor may not be able to condense the refrigerant properly, which can affect the overall performance of the refrigeration system.

In general, increased head pressure can also lead to other issues such as higher discharge temperatures and potential strain on the components of the refrigeration system. It is essential to maintain proper head pressure to ensure the system operates efficiently and effectively.