For the 1311-104 valve

Internal Safety Protection: Features a pressure-sensitive interrupter to disconnect the capacitor in the event of internal failure

and subcritical CO2 systems

the bimetal sensor in the switch has likely failed or drifted out of calibration

Carrier 48TJ500070 Fan Guard Grill 318518-761 For the 1311-104 valveThe Carrier 48TJ500070 Fan Guard Grill is a critical OEM replacement part designed specifically for commercial rooftop units and industrial air handlers. This heavy duty fan grille measures 29 inches by 29 inches with a 5 inch depth, providing a robust physical barrier that protects the fan blade assembly from debris ingestion and accidental contact. As a direct replacement for the Carrier 48TJ500 070, it ensures proper clearance and structural