What do terminal labels T1, T2, and T3 signify?

Terminal labels T1, T2, and T3 are typically used to designate the terminals on a three-phase compressor. In three-phase systems, there are three separate electrical inputs that supply power to the compressor, allowing it to operate efficiently. These labels help technicians identify the correct wiring configuration and ensure that the compressor is connected properly for balanced load and optimal performance.

In contrast, single-phase systems usually have only two terminals (often designated as L and N for line and neutral), and a fixed orifice label would not relate to terminal connections but rather indicate a specific type of refrigerant metering device. Similarly, while refrigerant system labels may include terminal designations, T1, T2, and T3 are specifically associated with three-phase compressor terminals. This distinction is crucial for HVAC technicians when diagnosing and servicing equipment to ensure proper functioning and to avoid electrical issues.