Compatibility between GFCI breakers and household adjustable speed drives

As manufacturers find more applications for adjustable speed drives (ASDs) in household appliances, ground fault circuit interrupter (GFCI) compatibility becomes crucial. As compared to industrial applications, the GFCI thresholds for residential applications are much lower. This work explores the compatibility issues that arise for a 1.5 hp (1.1 kW) ASD intended for use in a hot tub or spa. The experimental frequency response of a commonly-used GFCI breaker is compared to the common-mode current of a commercially-available ASD. To enhance compatibility, the input filter needs to be changed to reduce capacitance to earth.