A wiring diagram primarily shows what in an HVAC system?

• A. Wiring of components
• B. Piping layout
• C. Control logic
• D. Energy usage

Answer: (A)

The main concept here is the electrical connections between components in an HVAC system. A wiring diagram shows how power and control signals travel through the system, detailing which wires connect to which terminals, switches, relays, contactors, control boards, and sensors so you can trace circuits and diagnose faults.

This is why it’s the best answer: a wiring diagram’s purpose is to map the electrical interconnections, not the physical routing of pipes or the system’s energy consumption. Piping layout is captured in piping diagrams, not wiring diagrams. Energy usage data isn’t shown in a wiring diagram either; that information comes from performance calculations or metering. Control logic or sequencing is usually documented in separate control diagrams or logic schemes, though wiring diagrams may show the presence of control devices and basic interconnections.