A low pressure switch is a safety device that shuts down the Compressor if it detects that the refrigerant pressure has dropped too low. This is usually caused by a refrigerant leak or a severe airflow restriction in the Air Handler. Running a compressor with low pressure can lead to "oil starving" and mechanical burnout, so this switch is a vital protection for your ACIq unit. You can find replacement switches and diagnostic tools in our Parts department. In Mobile Home AC Condensers, this switch prevents the system from running if it's completely empty of gas, protecting the equipment from running "dry." It is a standard feature in high-quality systems and a critical part of passing mechanical inspections. Keeping your AC Coil Systems clean is the best way to prevent the nuisance trips caused by low pressure. It is the primary sensor that warns you when your refrigeration loop has lost its integrity.