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Commercial Refrigeration III

HVAC 233W

Commercial Refrigeration III

HVAC 233W

Course Description

Prerequisite: RHA 122 and RHA 225. Examines and identify refrigeration units associated with supermarket applications and the food industry. Diagnoses multiplex systems and self-contained equipment for medium/low temperature applications such as piping and trouble shooting mechanical and electrical components. (45-30)

Outcomes and Objectives

Demonstrate knowledge of multiplex commercial refrigeration systems.

Objectives:

  • Define different types of multiplex systems.
  • Explain the applications for multiplex systems.
  • Describe how compressors are connected on a rack system.
  • Describe physical construction of a rack and associated piping.
  • Explain the advantages of a multiplex system.
  • Identify an even or uneven parallel compressor rack.
  • Define a cascade and centrifugal system.

Demonstrate knowledge of commercial refrigeration/multiplex controls.

Objectives:

  • Explain and set oil controls on rack systems.
  • Explain and adjust oil controls on a multiplex compressor system.
  • Explain and adjust valves in the piping on a multiplex system.
  • Explain and adjust compressor cycling controls.
  • Explain and adjust condenser controls.

Identify defrost types and their operations.

Objectives:

  • Explain hot gas defrost cycle.
  • Explain cycle off defrost cycle.
  • Explain electric defrost cycle.
  • Setup and troubleshoot defrost systems.

Identify multiplex evaporator systems.

Objectives:

  • Explain and setup evaporators on multi-coil cases.
  • Set super heat adjustments on multi-coil cases.
  • Explain and adjust EPR valves for multi-case system.
  • Explain and adjust temperatures on multi-case systems.

Diagnose and repair multiplex systems.

Objectives:

  • Diagnose high side and low side problems on a multiplex system.
  • Diagnose temperature problems on evaporators and condensers.
  • Diagnose evaporator problems and defrost cycle problems.
  • Diagnose mechanical problems with the compressor systems.
  • Diagnose electrical controls and three-phase power problems.