Automotive air-conditioner having electric heater and electrically driven compressor

摘要

An air-conditioner for use in an electric vehicle or a hybrid vehicle includes an electric heater for heating water circulating through a heater core and a compressor for compressing refrigerant in a refrigeration cycle. The electric heater is powered by an on-board battery, and the compressor is also driven by the same on-board battery. When a voltage of the on-board battery abnormally increases to a first predetermined level, the electric heater is switched off to prevent the electric heater from being overheated. When the voltage further increases to a second predetermined level, operation of the compressor is also terminated. Thus, the electric heater is properly protected from the abnormally high voltage while properly keeping performance of the air-conditioner.