LOW PRESSURE (LP) SWITCH

Low-Pressure Switch in an HVAC System

Low-pressure switches serve as vital safety components within HVAC systems. True to their name, these switches are designed to monitor refrigerant pressure levels, typically installed on the suction line. They continuously assess the refrigerant levels, and if the pressure falls below the acceptable operating range, they quickly detect this drop and send a signal to the control panel, prompting the HVAC system to stop.

The choice of a low-pressure (LP) switch depends on the specific refrigerant being utilized, as each type has distinct operational pressure requirements.

Standard LP Switch Settings for Common Refrigerants:

• R22: Ranges from 25 psi to 35 psi
• R134a: Ranges from 25 psi to 35 psi
• R410A: Ranges from 50 psi to 70 psi
• R32: Typically between 50 psi and 70 psi, with most HVAC applications falling between 20 psi and 30 psi

For precise pressure settings related to refrigerants like R407 and R404, it is crucial to refer to the manufacturer’s specifications.