Legally, it should not. But you never know what a manufacturer might assert. Micro-Air is quite confident that its product cannot damage your compressor. You can google the Magnuson–Moss Warranty Act and the voiding of warranties for adding an aftermarket part. The aftermarket part needs to have a causal effect to void the warranty.
** Note on the below statement: Applicable to RV Rooftop Air Conditioners
Some RV owners worry that their installation of an EasyStart 364 might in some way void the manufacturer’s warranty on their rooftop AC unit’s compressor motor.
Worry no more! We offer an inexpensive Extended Warranty covering your AC unit’s compressor motor for the duration of your AC manufacturer’s warranty if it will not cover the repair or replacement of the compressor under warranty.
If purchased, this Extended Warranty shall create certain rights and duties between the parties which shall be in addition to and shall not be exclusive of the Limited Warranty appearing on the Company website.