Patent ID: 7760497

Claim:
A powered controlled acceleration suspension work platform hoist control cooling system ( 1000 ) housed in a sealed control enclosure ( 1100 ) formed of a plurality of enclosure sidewalls ( 1110 ), wherein the hoist control cooling system ( 1000 ) is in electrical communication with a constant frequency input power source ( 800 ) and a hoist motor ( 1200 ), comprising: (A) a variable frequency drive ( 1300 ) in electrical communication with the constant frequency input power source ( 800 ), and having a rectifier ( 1310 ), a dc bus ( 1320 ), and an inverter ( 1330 ), wherein (1) the rectifier ( 1310 ) converts the constant frequency input power source ( 800 ) into direct current power; (2) the dc bus ( 1320 ) receives the direct current power from the rectifier ( 1310 ) stores the direct current power; (3) the inverter ( 1330 ) controls the discharge of the direct current power from the dc bus ( 1320 ) to the hoist motor ( 1200 ); (B) a cooling system ( 1400 ) in electrical communication with the constant frequency input power source ( 800 ), wherein the cooling system ( 1400 ) includes: (1) an inverter temperature sensor ( 1500 ) measuring a temperature of the inverter ( 1330 ) and generating an inverter temperature signal; (2) an ambient temperature sensor ( 1600 ) measuring a temperature of the ambient air in the sealed control enclosure ( 1100 ) and generating an ambient temperature signal; (3) a cooling system controller ( 1700 ) in communication with the inverter temperature sensor ( 1500 ) and the ambient temperature sensor ( 1600 ), wherein the cooling system controller ( 1700 ) receives the inverter temperature signal and the ambient temperature signal and generates an inverter cooling signal and an ambient cooling signal; (4) an inverter cooler ( 1800 ) in physical contact with at least a portion of inverter ( 1330 ) and a portion of one of the plurality of enclosure sidewalls ( 1110 ), the inverter cooler ( 1800 ) in communication with the cooling system controller ( 1700 ) to receive the inverter cooling signal, wherein the amount of heat that the inverter cooler ( 1800 ) removes from the inverter ( 1330 ) and rejects to the enclosure sidewall ( 1110 ) is controlled by the inverter cooling signal; and (5) an ambient cooler ( 1900 ) in the sealed control enclosure ( 1100 ) and in communication with the cooling system controller ( 1700 ) to receive the ambient cooling signal, wherein the amount of heat that the ambient cooler ( 1900 ) removes from the control enclosure ( 1100 ) is controlled by the ambient cooling signal.