The device that prevents automatic restart after a fault in cooling systems is called a

The device that prevents automatic restart after a fault in cooling systems is called a

• A. Low-Pressure Switch
• B. Lockout Relay
• C. Pressure Sensor
• D. High-Limit Switch

Answer: (B)

Lockout relays are used to prevent automatic restart after a fault. When the control detects a fault, the lockout relay latches the circuit open, so the compressor and other equipment won’t restart even if the fault condition clears. A manual reset (or power cycling) is typically required to restore normal operation. This ensures you don’t get immediate restart and potential damage or unsafe conditions from a lingering fault. Other devices have protective roles but don’t function as a restart blocker after faults. A low-pressure switch shuts down the system if refrigerant pressure drops too low, but it doesn’t lock out future startups after a fault. A pressure sensor provides data to the control but doesn’t itself enforce a restart lockout. A high-limit switch protects against overheating by opening the circuit, but it is not designed to permanently prevent automatic restarts after faults.

Lockout relays are used to prevent automatic restart after a fault. When the control detects a fault, the lockout relay latches the circuit open, so the compressor and other equipment won’t restart even if the fault condition clears. A manual reset (or power cycling) is typically required to restore normal operation. This ensures you don’t get immediate restart and potential damage or unsafe conditions from a lingering fault.

Other devices have protective roles but don’t function as a restart blocker after faults. A low-pressure switch shuts down the system if refrigerant pressure drops too low, but it doesn’t lock out future startups after a fault. A pressure sensor provides data to the control but doesn’t itself enforce a restart lockout. A high-limit switch protects against overheating by opening the circuit, but it is not designed to permanently prevent automatic restarts after faults.