Danfoss ACB-2UC56W Cartridge Pressure Switch (061F9054) – High Pressure 28/21 Bar, Automatic Reset

Danfoss ACB-2UC56W (code 061F9054) is a cartridge-type pressure switch that protects the compressor in refrigeration and air conditioning circuits against excessive discharge pressure. In the trade it is also known as Y.B.O. (high pressure cut-out).

Fixed High Pressure Safety: Cuts Out at 28 Bar, Cuts In at 21 Bar

The switch is factory-set: when the pressure rises to 28 bar, the contact opens and the compressor stops; when the pressure drops to 21 bar, the contact closes by itself (automatic reset). The 7 bar differential prevents the compressor from cycling on and off continuously.

What does cartridge type mean? It is a compact switch without adjustment knob, scale or housing that screws directly onto the line. Instead of an adjustable pressure switch, it provides a fixed safety point that cannot be changed and takes up no space in the panel. The fact that the setting cannot be changed in the field is an advantage for the safety function.

Technical Specifications (Official Manufacturer Data)

• Model: Danfoss ACB-2UC56W | Code: 061F9054
• Cut-out: 28 bar | Cut-in: 21 bar
• Reset: Automatic
• Contact: SPDT | Load: AC 4 A / 250 V
• Max. Working Pressure: 45 bar | Burst Pressure: 200 bar
• Connection: 1/4 inch female flare, with valve depressor
• Protection Class: IP65 | Net Weight: 0.114 kg
• Certificates: cULus UL60730 · CE · CE 0035 · PED · TÜV | EAN: 5702428259880

• ⚠️ The setting cannot be changed in the field. Your system's design pressure and safety relief valve setting must be above this switch's 28 bar cut-out value.
• 🔧 The connection with valve depressor allows the line pressure to be released in a controlled way when the switch is removed; nevertheless, make the circuit safe before removal.
• A high pressure trip is always a symptom of a fault (dirty condenser, stopped fan, overcharge, blocked line). Automatic reset restores the circuit but does not fix the fault — if it recurs, look for the root cause.
• For different settings, other codes of the ACB family are used; our catalog also includes ACB models with other set points.