Basic Electrical Safety Rule(s)

The OSHA regulation regarding electrical safe practices states two very important basic points. The first
is that live parts shall be de-energized before working on or near them. The second point is that even
after the exposed parts have been de-energized, they shall still be treated as energized until they are
locked out and/or tagged out. That is why the BASIC RULE for electrical safe practices procedure is
stated as follows;
ALL ELECTRICAL CIRCUIT CONDUCTORS, BARE OR INSULATED, ARE ASSUMED TO
BE ENERGIZED UNTIL PROVEN OTHERWISE. THEY SHALL BE DE-ENERGIZED,
LOCKED OUT AND TESTED FOR THE ABSENCE OF VOLTAGE BEFORE WORKING ON
THEM OR WORKING NEAR THEM. WORK ON ELECTRICAL CIRCUIT CONDUCTORS
MAY ONLY BE PERFORMED BY QUALIFIED PERSONNEL WHO HAVE BEEN
AUTHORIZED TO DO THE WORK.
As with any procedure, revisions are commonplace. Workers should always check to ensure they are
working from the latest revision when using a procedure.
The safest way to avoid electrical hazards is to de-energize the conductors to be worked on or near, and,
assure that they cannot be re-energized. This is known as putting the conductors in an electrically safe
work condition and should always be your first consideration.
An electrically safe work condition will be achieved and verified by the following process:
1) Determine all possible sources of electrical supply to the specific equipment. Check applicable upto
date drawings, diagrams and identification tags.
2) After properly interrupting the load current, open the disconnecting device(s) for each source.
3) Where it is possible, visually verify that all blades of the disconnecting devices are fully open or that
drawout type circuit breakers are withdrawn to the fully disconnected position.
4) Apply lockout/tagout devices in accordance with a documented and established policy.
5) Use adequately rated voltage detector to test each phase conductor or circuit part to verify they are
de-energized. Before and after each test, determine the voltage detector is operating satisfactorily.
6) Where the possibility of induced voltages or stored electrical energy exists, ground the phase
conductors or circuit parts before touching them. Where it could be reasonably anticipated that the
conductors or circuit parts being de-energized could contact other exposed energized conductors or
circuit parts, apply ground connecting devices rated for the available fault duty.
Working On Or Near Energized Conductors
OSHA also spells out the rules for working on or near energized parts. Energized parts that operate at
less than 50 volts to ground do not have to be de-energized before working on or near them, if you are
sure there are no other hazards which could occur.
If the electrical circuit conductors are 50 volts or more to ground you cannot work on them energized,
except under very restrictive conditions. OSHA rules will allow you to work on or near energized
circuit parts if you can prove that de-energizing introduces additional or increased hazards. OSHA also
permits this type work if de-energization is infeasible due to equipment design or operational
limitations.
Some examples of additional or increased hazards might be the de-activation of an emergency alarm
system or shutting down a hazardous location ventilation system. Testing, some forms of
troubleshooting, or the impracticality of shutting down some continuous industrial processes are
examples of infeasibility.
Working on or near electrical conductors or circuit parts which are or may become energized shall only
be done by qualified employees who have been trained to recognize electrical hazards and have been
trained to avoid injury by using safe practices, precautionary techniques and protective equipment.
Working on or near exposed energized conductors requires extensive planning and higher level
management approvals. With the exception of testing, working on or near energized circuit parts will
usually not be approved.
The OSHA rules only give safe approach distances and clearances to overhead lines.