Continuation of the NCCER Level 4 electrical curriculum. This course Covers various types of transformers, and provides information on selecting, sizing, and installing them. Discusses applications and operating principles of various control system components, such as solid-state relays, reduced-voltage starters, and adjustable-frequency drives. Covers basic troubleshooting procedures. Provides a basic overview of HVAC systems and their controls. Also covers electrical troubleshooting and NEC® requirements. Presents heat-tracing and freeze-protection systems along with various applications and installation requirements.