Variable frequency drive cabinet ventilation system, apparatus and method

A variable frequency drive (VFD) cabinet comprising:

• an internal air closed circuit inside the VFD cabinet that extends through an inside of an air-to-air heat exchanger;
• an external air open circuit extending through a positive pressure fan and then around an outside of the air-to-air heat exchanger;
• the internal air closed circuit circulating through a chamber closed to ingress of external air, the chamber comprising electrical components of a VFD system;
• the external air open circuit making a 180 degree turn from downwards to upwards as the external air circuit flows underneath a vertical plate above and proximate to a floor of the VFD cabinet before flowing through a VFD chassis comprising a drive of the VFD system.

A variable frequency drive (VFD) cabinet ventilation method comprising:

• flowing outside air downwards through a booster fan into a VFD cabinet;
• boosting a pressure of the downwards flowing outside air with the booster fan;
• passing the downwards flowing outside air passed an outside of a heat exchanger inside the VFD cabinet;
• turning a flow of the downwards flowing outside air to upwards flowing outside air, the turn causing the separations of dirt from the outside air;
• moving the upwards flowing outside air through a VFD chassis comprising a drive before sending the upwards flowing outside air out of the VFD cabinet by guiding the outside air from an upwards flow to a horizontal flow through a curved exit vent;
• and
• circulating internal cabinet air through a closed circuit extending from a chamber and then through an inside of the heat exchanger to cool the internal cabinet air, the chamber sealed from the outside air and comprising portions of a VFD system.