Five Misoperation-Prevention Logic in Substations

Measures to Prevent Five Types of Misoperation Accidents

Any primary electrical equipment that could cause electrical misoperation accidents should be equipped with anti-misoperation devices. These devices should provide the following basic functions:

• Prevent incorrect opening or closing of switches;
• Prevent operating isolating disconnectors under load;
• Prevent applying or closing grounding conductors on live equipment;
• Prevent closing switches or isolating disconnectors while grounding conductors are applied;
• Prevent unauthorized entry into live compartments.

Basic Requirements for Anti-Misoperation Interlock Logic

The interlock logic should implement the five misoperation-prevention requirements.

Circuit breakers and switches may use advisory measures to prevent incorrect opening or closing.

All electrical components other than switches should use mandatory interlock measures.