Schneider Electric (Square D) LRD21 Overload Relay 318820-201 if you hear mechanical grinding

if you hear mechanical grinding or squealing

which is the industry standard for most small to mid-sized smoke dampers

The IO Hvac Controls ZP4-ESP is a professional-grade 4-zone universal control panel designed to streamline multi-zone forced air installations

it provides the necessary electromagnetic force for precise solenoid valve actuation

Schneider Electric (Square D) LRD21 Overload Relay 318820-201 if you hear mechanical grindingThe Schneider Electric Square D LRD21 Thermal Overload Relay is designed to provide reliable motor protection for three phase motor control applications. Part of the TeSys Deca motor control range, this 12 18A overload relay features a Class 10A tripping characteristic and is engineered to help protect motors against overload conditions and phase failure. Designed for direct mounting with compatible TeSys D contactors including LC1D18, LC1D25, LC1D32,