NEC Exception for Written Procedures

NEC 430.102(A) allows for an exception to the local disconnect requirement for industrial machinery if: Written procedures are established and implemented to ensure that the equipment can be disconnected from all energy sources. The procedures are developed and implemented under the supervision of a qualified person. The procedures clearly identify the equipment that is to be disconnected and the energy sources that supply it.

Interpretation of Procedures

The written procedures must be: Specific to the equipment

They must clearly identify the machine(s) to which they apply.

Comprehensive

They must cover all necessary steps to disconnect the machine from all energy sources, including electrical, mechanical, and hydraulic.

Detailed

They must provide step-by-step instructions, including the use of specific tools or protective equipment.

Accessible

They must be readily available to authorized personnel at the machine location.

Timing of Written Procedures

The NEC does not specify when the written procedures must be in place. However, it is generally recommended that they be developed and implemented before the equipment is installed and commissioned to ensure safety during the installation process.

Additional Considerations

In addition to the NEC requirements, employers may have their own policies and procedures regarding written procedures for machine disconnects. These policies may include: Regular review and updating of procedures Training and certification of personnel on the procedures Documentation of the completion of the disconnect procedures Flag for review