Danfoss KPS31 or CAS 15B (Check voltage and range).
The PSU 15B is a switch. Unlike an automatic switch that restarts when pressure drops, this one stays open after tripping. The operator must physically press the reset button (usually red) on top of the switch. This prevents the compressor from short-cycling under dangerous high-pressure conditions. danfoss pressure switch psu 15b manual
The "15B" designation refers to a specific pressure range and connection type. While Danfoss has released newer digital and electronic controls (like the KPI or CAS series), the PSU 15B remains widely used in legacy systems and is still available for replacement due to its mechanical reliability. Danfoss KPS31 or CAS 15B (Check voltage and range)
mounted to the main fuel line. The needle was dancing toward the red zone, and the manual—a grease-stained relic—was missing its critical calibration page "It’s a simple SPDT switch The operator must physically press the reset button
Understanding the spec sheet is vital. Below are the standard parameters for the Danfoss PSU 15B. , as revisions exist.