A lockout relay, also known as a safety relay or interlock relay, is a specialized electromechanical device used in electrical control circuits to ensure safe operation and prevent hazardous conditions. Its primary purpose is to isolate or disconnect electrical power to equipment or machinery under specific conditions to protect personnel and prevent damage.
The main function of a lockout relay is to provide a reliable means of locking out or isolating equipment from its power source during maintenance, repair, or unsafe operating conditions. This is typically achieved by integrating the relay into the control circuitry of machinery or electrical systems. When certain conditions are met, such as a fault detected, an emergency stop activated, or maintenance being performed, the lockout relay de-energizes its contacts to interrupt the power supply to the equipment.
Lockout relays can also be used in conjunction with other safety devices like emergency switches, safety interlocks, or programmable logic controllers (PLCs) to ensure comprehensive safety measures. For example, in industrial high voltage (HT) applications, lockout relays are crucial for isolating power to transformers, switchgear, or other critical equipment to protect personnel from electrical hazards during maintenance or fault conditions.
In essence, a locking relay operates similarly to a standard relay but includes additional safety features and mechanisms to ensure that equipment cannot be inadvertently powered during unsafe conditions. Its deployment in HT voltage environments enhances safety protocols by providing fail-safe isolation capabilities, thereby safeguarding personnel and equipment from potential electrical hazards.