Christopher Coache

NFPA 70E Series: Normal operation and you

Blog Post created by Christopher Coache Employee on Apr 6, 2017

 

Is it normal operation to throw the switch of a circuit breaker? What about opening an access panel to get to that breaker? How about racking out a breaker? Or replacing a light bulb? The manufacturer probably states that the switch on the breaker is meant to be thrown, the access panel is intended to be opened, the breaker is designed to be racked out and the light bulb is intended to be replaced. That makes each of these tasks part of normal operation of the equipment. Doesn’t it? And if it is, doesn’t that mean that the task can be performed while the circuit is energized?

Not only is this equipment intended to do these things they are designed to do these things. That circuit breaker is only intended to be used as a switch if it has been evaluated as such. The handle itself does not make throwing the switch normal operation of the breaker. You may think that replacing a light bulb is not normal operation (even though the bulb is accessible, is intended to be replaced, and the base is designed to have the bulb removed). You may also think that there is no need to replace a light bulb while it is energized. You may think that way for a light bulb but may see a difference with racking out a breaker without de-energizing. (I know these next statements will be controversial so I don’t intend to reply to all the negative comments that will be made.) A breaker is meant to function as a circuit protective device. That is its intended normal function. If the breaker has to be racked out to function as a protective device, I would consider that normal operation. The breaker may be designed to be removed and so is that light bulb but removal is not part of their normal operation. That is the installation of those pieces of equipment. Yes, the equipment may be arc-rated or there might be justification for energized work but that is not what I am addressing. This discussion is about normal operation.

A piece of equipment is designed to perform a function. It could be overcurrent protection, temperature measurement, power conversion, or to provide light. That equipment is also designed to have an operator interact with it in order for it to perform that function. There are ON/OFF switches, dials to turn, and buttons to press. These things are what I consider normal operation of the equipment. It is what an operator must do to get the equipment to perform its function once it has been installed.

NFPA 70E® does not define normal operation for any piece of equipment because that is well beyond its scope. So the interpretation is up to you. NFPA 70E does define conditions when normal operation is permitted. You must determine that those conditions have been met before permitting your employee to interact with equipment in a manner that meets your perception of normal operation of that piece of equipment.

Next time: What your label says about personal protective equipment (PPE)

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