1. If the vacuum circuit breaker truck inside the high-voltage switchgear is closed while in the "test" position, it cannot be moved into the "service" position. (Prevents accidental opening/closing of the circuit breaker)
2. If the earthing switch inside the high-voltage switchgear is in the closed position, the circuit breaker truck cannot be closed. (Prevents closing the circuit breaker while the earthing switch is engaged)
3. When the vacuum circuit breaker inside the high-voltage switchgear is closed and in service, the rear panel door is mechanically interlocked with the earthing switch mechanism. (Prevents accidental entry into a live compartment)
4. When the vacuum circuit breaker inside the high-voltage switchgear is closed and in service, the earthing switch cannot be engaged. (Prevents applying the earthing switch to a live circuit)
5. When the vacuum circuit breaker inside the high-voltage switchgear is closed and in service, the circuit breaker truck cannot be withdrawn from the "service" position. (Prevents disconnecting the circuit breaker under load)
