Applying and Removing Protective Grounds
Hey guys, just wanted to share some tips for applying and removing personal protective grounds. Feel free to contribute or comment.
Step 1: De-energize the line in accordance with procedures. Use a documented LOTO procedure to be certain that the circuit or equipment has been de-energized and isolated from all sources of hazardous energy. Temporary protective grounds should be placed to create an equipotential zone in the working area at the work location, preferably.
Step 2: Test the circuit for voltage. Don't assume that the circuit has been de-energized just because it's been turned off. Other sources of energy, such as induction from nearby circuits, can result in lethal shocks and other injuries.
Step 3: Clean all connections. Extra resistance caused by corrosion and dirt should be eliminated to maintain an extremely low resistance to ground, otherwise single point grounding will be ineffective.
Step 4: Apply ground-end clamps first, and remove them last. This assures there is no time during installation in which the operator could become the lowest-resistance ground path. Mechanical connections should be strong enough to withstand forces generated by electromagnetic induction.
Step 5: Conductor-end clamps must be applied and disconnected by hot sticks of adequate rating and length. If it is physically impossible to use hot line tools for the application of grounds, additional shock and arc rated PPE is required for worker protection.
Good list. Don't forget that safety grounds are sized with consideration to the available short circuit current and duration of the fault. Safety grounds should not be of excessive length because they could start to move violently under a fault condition and injure someone. Reference NFPA 70B Section 220.127.116.11.4
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