I need to know if my training is lacking or if a concern from a manager has no merit. The manager is insisting that 30 cal flash gear is needed to reset a tripped 3000A 480 VAC main breaker. The breaker and all the gear around it is fully enclosed. The Approach is 26.5 ft and limited is 3.6 feet. Am I wrong to assume that these barriers only apply with the covers open. I definitely will need to review 70E to set myself or the manager straight. I appreciate his zeal to keep us safe but this seems extreme. What do you all think?

If the covers are all on, no PPE is required, much less a 30 cal suit.

Ask the manager if he puts on flash gear to reset one of his breakers at home

Is there any concerns over what tripped the 3000 amp main?

Hopefully it was the GF

Appropriate PPE is always required, regardless of covers being present or absent.

closed covers mitigate any possible shock incident, and they probably do help in the prevention of an AF occurrence, but the do nothing to lower the amount of incident energy.

While I might judge the 'normal operation' of a 3000A breaker between open and closed as having a low risk of an AF occurring, there is no way I would 'reset' a tripped breaker without PPE based on the available incident energy.

The PPE requirements need to be part of the company's Electrical Safe Work Practice program.

So the outside consultant with a vested interest in separating you from your money, will specify the most conservative interpretation of the 70E rules in order to validate their cost to the company. Meanwhile you will need PPE to plug in a vacuum cleaner in the office spaces.

Bob,
Refer the manager to Table 130.7(C)(15)(a) of 70E,
available @
http://www.depts.ttu.edu/opmanual/OP60.14B.pdf

It lists the Hazard/Risk Category Classifications.

Panelboards or Switchboards Rated >240 V and up to 600 V (with molded case or insulated case breakers)

CB or fused switch operation with covers on

Hazard Risk = 0
______________________________________________________

600 V Class Switchgear (with power circuit breakers or fused switches)

CB or fused switch operation with covers on

Hazard Risk = 0

If the people doing your analysis are the same ones that are selling you your PPE, you probably have a point.

My point is; it is not a requirement of NFPA70E that you employ any more PPE than is necessary to perform the task.

The typical AF study says how bad things could be (the hazard), not how likely they are to occur(the risk).

70E clearly says that the risk must be analyzed as well as the danger. The is partly why their 'task tables' result in a Hazard Risk Category instead of simply cal/cm^2.

And make sure that all of the conditions (fault current, opening times, and regular maintenance) are met.

This is like most things "safety" related. If it is worth doing, it is worth over doing.

You only have to look ad lead paint and asbestos abatement this in action. Someone dug up some sewer pipe here in a road expansion project that *might* have had some asbestos in it and instead of some reasonable response, they shut down the project for months, hauled about 100 yards of dirt for "safe disposal" and treated the pipe like it was plutonium. Everyone involved was punished in some way and the contractor went bankrupt. An overpass took years and many extra millions to complete.

Thank you all for your responses.
We evaluated the possible cause and isolated all loads before we reset the main breaker. We had an outside contractor with 30cal suit reset the breaker to keep everyone happy. We then turned on the unrelated breakers to the suspected cause. Suspected Load: A motor control center feeder breaker had also tripped with the mains and there was a report of a BANG when a pump was started. Then we investigated and found that the Motor Control Center bucket for the pump had melted its buss clips and damaged the buss. Hard to tell if it flashed to ground or phase to phase.

Nice to see a thread on 70E. Seems most people in this trade never even heard of it. I bring this up all the time. I made my employer get me a Proper Arc Flash shield. I use it every time I remove a panel cover. If I suspect a problem, I will than put on my FR shirt.
I have been in your circumstance many times. Show the ignoramous the literature., ie 70E

0 Risk as stated by others. However I personaly will put on FR shirt, hot gloves and shield/hard hat to reset such a breaker. You never know.

While we are on this topic I would like to pose a question...not to hijack the thread:
Many years ago, a instructor I had in my 3rd year apprenticeship, was explaining about how a breaker can store energy, enough to kill you if you closed it. If I remember correctly it was along the lines of say there is a lightning strike, the utilities circuit breaker is antiquated and doesn't open. Current travels through line to residence or building with improper grounding. That or some of the e=nergy could store in your tripped main. seems impossible however he was pretty convincing! You reset breaker and that energy comes out of panel and basically cuts you in half. I have never read or heard of this.
1) Is this possible?
2) Have any of you heard of this?

If so, a 0 Risk for resetting tripped breaker with panel cover on seems egregious.

Breakers do not store any energy, nor does any energy actually flow through an open one.
What does happen is enormous amounts of energy can be released when the contacts close on a bolted fault.

Greg's right on that.
Having repaired and rebuilt breakers all the way up the 15kV ones I can confirm that a circuit breaker is basically just a knife switch with tons of stuff to make it move quickly and a fair amount of stuff to snuff out the arc that is created at the moment that the breaker opens. Once it has opened, it's dead and harmless (unless there are charged springs in it waiting to break an unwary finger).

As Greg stated, there is no 'stored' energy within a circuit breaker.

Closing a cb with a fault on the load side can cause catastrophic situations.

Check out the Bussmann website for a lot of graphic info on fault current situations.