HVAC is a big user of energy so we see a lot of interest in monitoring the energy used by compressors. When doing to we also log valuable diagnostic information about the electrical environment in which the compressors are operating and the performance of the compressors themselves.

• THDV: The total harmonic content of the voltage at the input of a compressor gives an indication of supply quality. If above a threshold of around 5%, this can serve as a warning that there may be supply-side issues such as poor tightening of terminations and high-impedance joints in the supply circuit.
• THDI: Drift in the total harmonic content of the current drawn by a compressor may be a sign of deterioration and possible impending failure of components and terminations. The data we generate allows maintentnace teams to log THDI and get early warning of potential failures before they happen, allowing interventions with the aim of avoiding costly HVAC outages.