3041921 Thermo King High Pressure Cut-Out Switch

The Thermo King 3041921 is an OEM high pressure cut-out (HPCO) safety switch used in Thermo King transport refrigeration systems.

It is designed to protect the refrigeration compressor and system by shutting the unit down when discharge pressure becomes too high.

This prevents damage from conditions such as:

• Condenser airflow failure

• Overcharged refrigerant system

• Blocked condenser coil

• High ambient temperature operation

It is a normally closed safety switch that opens on high pressure.

SPECIFICATIONS

• Manufacturer: Thermo King

• Part Number: 3041921

• Type: High Pressure Cut-Out (HPCO) switch

• Function: Compressor safety shutdown

• Circuit Type: Normally closed (NC)

• Cut-Out Pressure: ~31 bar (~450 PSI range equivalent)

• Cut-In / Reset Pressure: ~21–22 bar (~310 PSI range equivalent)

• Connection Type: 7/16"-20 UNF or system manifold mount (varies by application)

• Application: Transport refrigeration systems (truck/trailer units)