Master Trip Relay 86 is a high-reliability protection and tripping relay used in electrical power systems to initiate and coordinate the tripping of circuit breakers during serious fault or abnormal operating conditions. Also known as ANSI 86 Lockout Relay or 86 Master Trip Relay, it is commonly used in transformers, substations, switchgear, protection panels, and industrial electrical systems.
The Master Trip Relay receives a trip command from protection devices such as Buchholz Relay, Differential Protection Relay, Overcurrent Relay, Earth Fault Relay, Oil Surge Relay (OSR), Restricted Earth Fault (REF) Relay, Pressure Relief Device (PRD/PRV), and other protective relays. Once energized by a fault signal, the relay operates its output contacts to trip the associated circuit breaker and isolate the faulty equipment from the electrical system.
A key feature of an ANSI 86 Lockout Relay is its latching or lockout function. After operation, the relay remains in the tripped position until it is manually reset. This prevents the circuit breaker from being re-energized automatically after a major fault and ensures that the fault condition is investigated before the equipment is put back into service.
 
Applications
Master Trip Relay 86 is widely used for power transformers, distribution transformers, substations, HT/LT switchgear, electrical protection panels, transformer control panels, generator protection systems, industrial plants, and power distribution systems. It can be integrated with transformer protection schemes and circuit breaker trip circuits.
 
Key Features
ANSI 86 Master Trip / Lockout Relay
Suitable for transformer and switchgear protection
Latching mechanism for reliable lockout operation
Manual reset after trip operation
Multiple contacts for trip, alarm, and indication circuits
Suitable for integration with various protection relays
Reliable operation for critical electrical protection systems
Available in different coil voltage and contact configurations
Designed for panel and control circuit applications
Master Trip Relay 86 provides dependable fault isolation, ci