MARS 43346 Pressure Switch

The MARS 43346 Pressure Switch is a heavy-duty Single-Pole Single-Throw (SPST) low-pressure control designed for demanding HVAC and refrigeration applications. Engineered for precision and longevity, this automatic reset pressure switch features a fixed setpoint configured to open on a pressure drop at 25 PSI and close on a rise at 50 PSI. The MARS 43346 is a versatile HVAC low pressure switch compatible with a wide voltage range from 24V to 250V, making it an ideal choice for residential air conditioning, heat pumps, and commercial refrigeration units. Its compact, direct-mount design utilizes a 1/4" female flare connection for seamless integration into existing refrigerant lines. With a robust hermetically sealed sensor and tamper-proof construction, this switch provides critical compressor protection by preventing operation during low-pressure scenarios. Built to withstand extreme conditions, it maintains consistent performance across temperatures ranging from 20°F to 176°F, ensuring reliable system monitoring for professional HVACR contractors.

• Automatic Reset Functionality: Eliminates the need for manual intervention by automatically restoring circuit continuity once pressure stabilizes at 50 PSI.
• Universal Application Range: Rated for use with both 120V and 240V systems (carrying up to 34.8 LRA at 120V), suitable for R-410A and traditional refrigerant setups.
• Durable Construction: Features 18-inch color-coded lead wires and a vibration-resistant housing designed for direct mounting on suction lines.
• Enhanced Safety: Protects high-value compressors from burnout and catastrophic failure caused by refrigerant loss or coil freeze-ups.

• What are the exact trip points for this switch? The MARS 43346 is factory-set to open the circuit when system pressure falls to 25 PSI and will automatically reset (close) when pressure rises back to 50 PSI.
• Can this be used on high-pressure side applications? No, this is specifically a low pressure control. For high-side protection, a switch with higher PSI setpoints (such as the MARS 43330) should be utilized.
• How is this switch installed? It features a 1/4" female flare fitting for direct mounting on many standard refrigerant service ports, reducing the need for additional capillary tubes or mounting brackets.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.