If the equipment and task satisfy the criteria for Normal Operating Conditions, the answer is “No.”
You do not need PPE.
If the equipment and task do not satisfy the criteria for Normal Operating Condition, the answer is “Yes.”
You do need PPE.
The equipment is properly installed.
The equipment is properly maintained.
The equipment is used as intended and in accordance with manufacturer’s instructions.
The doors are closed and secured.
The covers are in place and secured.
There is no evidence of impending failure.
This means that the equipment is installed in accordance with applicable industry codes and standards along with the manufacturer’s recommendations. Has the equipment been inspected? If not, can you show that it is installed per the NEC? In many buildings, electrical projects are conducted by in-house personnel. Make sure the equipment has been installed safely and properly.
This starts with the preventive maintenance (PM) program. Does your PM program test and inspect according to manufacturer’s recommendations? Can you show preventive maintenance records on the equipment? Has any recommended corrective action been performed? NFPA 70B – Recommended Practice for Electrical Equipment Maintenance provides valuable guidance on proper equipment maintenance.
Sounds straightforward, but we have all seen situations in which the equipment is used for something other than its intended function. Hammers are for driving nails, not painting walls. Intended use also means that the equipment is performing the proper function within its range of tolerance. A 100-amp breaker with consistent load of 105 amps is not being used as intended. In fact, most breakers are only rated for 80% of continuous load.
This means the doors between the worker and exposed, live electrical parts. This does not mean the hinged front panel door on a panelboard or breaker panel.
Secured means that all screws, bolts, and other fasteners are in place and none are missing.
Use your senses for this. Do you hear, smell, or see anything that points to a problem with the equipment? Is there evidence of arcing, overheating, loose connections, or visible damage?
? To answer that question for a particular piece of equipment, you need to go through each of the six criteria. If any of these conditions are not met, you will need to look for ways to do the work de-energized or utilize the proper PPE. If, however, you satisfy all of the criteria of a normal operating condition, there is no reason to assume that it is unsafe.
Before resetting a tripped breaker, you need to know why the breaker tripped. If you can prove that it tripped because of an overload condition, then it can be safely reset. If you can’t prove that it was an overload or you don’t know why it tripped, you must assume that it doesn’t meet the conditions of number 6 above. In other words, this is evidence of impending failure. A breaker tripping from something other than overload means that there is something wrong somewhere in the electrical system or with the breaker itself. Further investigation is required.
As you can see, determining what constitutes normal operating conditions is not straightforward. Stringent criteria must be met.
he lesson here is simple: The more robust and comprehensive your preventive maintenance plan, the more likely your equipment is considered normal.
Thank you for your time. Mitchell & Lindsey offers Arc Flash Risk Assessments and Electrical Safety Training. If we can be of service to you in these areas or if you have any questions about this article, please reach out to me at the email or phone number below.
Bobby Lindsey – CESCP
Mitchell & Lindsey – President
M: (502) 836-4217