If your application requires a local override button or LED indicator

sufficient for driving large-scale dampers and high-pressure valve assemblies

leading to sticking or electrical failure at the contacts

allowing the system to react instantly to dynamic load changes

and other 1k ohm PTC-compatible digital electronic controllers

Trane CNT4991 Pressure Switch R-410A If your application requires aThe Trane CNT4991 is a 10 inch SPST pressure switch engineered for precise atmospheric monitoring in high efficiency Trane and American Standard HVAC systems. This OEM air pressure switch features a single pole single throw (SPST) contact configuration, rated at 0. 1" WC (water column) for low pressure detection. It is designed to interrupt or complete the 24V control circuit (rated at 28 VA) when specific airflow or flue gas pressure thresholds are