Electrical Safety in the Workplace

Electrical Safety in the Workplace

First, I understand the basic logic of NFPA 70E about safe electricity use: when there is Shock Hazard, the best way to ensure safety is to completely shut down the power supply and Lockout tagout
To create “electrical safe working conditions”

What is Electrically Safe Work Condition?

A state in which an electrical conductor or circuit part has been disconnected from 10 parts, Tested to verify the absence of voltage, and, if necessary, Temporarily grounded for personnel protection.

In order to ensure the safety of electrical equipment testing or maintenance work, it is indeed the best way to cut off the power supply, but we have to carry out a lot of work under live conditions, and once the power failure will cause greater loss; These special cases are explained in the standard, which we will discuss later.

When EHS personnel establish electrical safety or live working procedures,
The rule to follow must be “take power off operation as the first choice”.
NFPA 70E, ARTICLE 110 General Requirements for Electrical Safety-related Work Practices, provides recommendations on how to establish Electrical Safety procedures. Detailed requirements are made for electrical safety procedures, training requirements, employer and contractor responsibilities, electrical testing equipment and facilities, and leakage protectors.  

Here’s what I found interesting:

The Qualified Person (generally referred to as the authorized Person) is not Qualified after a simple training, because the Person needs to test or repair live equipment and may enter the Restrited Approach Boundary area, which has a high chance of being in contact with Arc Flash. So the standard has detailed requirements for qualified personnel.
Qualified Person must be able to judge which live parts are and what the voltage is, and understand the safe distance of this voltage, and select the appropriate level of PPE accordingly. My simple understanding is that in addition to obtaining the electrician’s license, they should also receive special training from the factory and pass the examination, and such personnel must be re-evaluated every year.
When testing for live parts that may exceed 50V, the integrity of the test tool should be determined at a known voltage before and after each test.