Biosafety laboratory air -conditioner fan's switched systems

The utility model provides a biosafety laboratory air -conditioner fan's switched systems, includes: a plurality of converters are controlled through change frequency the forced draught blower with the rotational speed and then the control pipeline pressure of exhaust fan to provide fan frequency feedback signal and fault of frequency converter feedback signal, wind channel pressure sensor for detect supply air duct and exhaust pipe's pressure, controlling means for determine the operation forced draught blower and whether the operation exhaust fan breaks down according to received fan frequency feedback signal, fault of frequency converter feedback signal and supply air duct and exhaust pipe's pressure, and the operation forced draught blower and/or when the operation exhaust fan breaks down, start reserve forced draught blower and/or reserve exhaust fan. The utility model discloses not only can realize seamless handover under the circumstances of operating mode conversion, keep the pressure in laboratory to