Patent ID: 8810178

Claim:
A variable speed drive connected upstream to an electric power grid and downstream to an electric motor, the variable speed drive comprising: a main casing comprising a base and a main closure cover closing on the base; a rectifier module inside the casing and designed to rectify an AC voltage supplied by the electric power grid; an inverter module inside the casing and designed to transform a DC voltage into a variable voltage to be applied to the electric motor; a DC power supply bus connecting the rectifier module to the inverter module, the DC power supply bus including one or more bus capacitors assembled on an electronic circuit board making it possible to keep the voltage of the bus at a constant value, wherein the main closure cover comprises one or more openings each traversed by a bus capacitor, and a secondary closure cover fitting onto the main closure cover and covering the said one or more bus capacitors, the variable speed drive comprises a seal cut out to the shape of the one or more bus capacitors and arranged between and in contact with both of the electronic circuit board and the main closure cover, a base portion of the one or more bus capacitors that is connected to the electronic circuit board is contained within an interior of the main casing, an end portion of the one or more bus capacitors extends through the one or more openings, through the seal, outside of the interior, and into a volume that is outside of the main casing, and the secondary closure cover is removable and defines the volume, when fitted to the main closure cover, that is outside of the main casing and that includes the end portion of the one or more bus capacitors.