Classic generators might have a THD bigger than than 20%. THD is not a spec that generator companies ordinarily checklist, especially for standard generators, so it’s hard to understand what you’re having, but small THD is always a safe wager with inverter generators.T?t c? các s?n ph?m tr??c khi bán ra ??u ???c ki?m nghi?m nghiêm ng?t ?? ??