Can someone help me understand and relay the reasoning behind needing arc flash PPE when racking breakers in an MCC? The argument was that if the door needs to be open when racking the breaker it is obvious why you need PPE. If the door can remain closed and a breaker racked in via a small racking port, why do you need PPE when you could close the breaker without any PPE? We were just going by the table in 130.6.

I would say it's due to additional risk. As you know, the tables are risk based. For example, there is a higher risk for racking/unracking because of operator error. It is/has been the case where breakers are racked in to their final position in the closed position, drawing and arc, and...well you know the rest.

Mike

If an arc flash occurs, the doors may not remain closed and even if they do, energy can still be released through any hole, vent etc. The link is to a video where I have 2 arc flash tests. The second one is 18,000 amps and it blows the door open. Hope it helps give you better feel for what happens.

VIDEO: Doors Blowing Open

Why not implement remote racking from outside the boundary?

Yes, you wear PPE to do this process. If you watched Jim's video, you saw that the doors don't necessarily stay closed and keep an arc flash contained. How a latched door can open is another question, but they do fly open.
The question I have is how often do you do this process? Seems like racking a breaker in or out of a MCC is not a standard process. If you do this on a regular basis, I'd want to know why and is it really so important?

For clarity the work task is racking a power circuit breaker in or out of switchgear, not an MCC.

Follow a procedure, turn off the load following normal procedures. Line side is energized. Open door racking is recommended as if there is any pressure it will be reduced.

Before the work task is executed, has your employer completed a risk assessment procedure for the work task? The RAP will include the work task's shock risk assessment and arc flash risk assessment with the outcome determining additional protective measures.

The overall Job and individual work task's risk assessment includes a review of the potential injury or damage to health and likelihood of occurrence to determine the hierarchy of risk control methods to apply to eliminate exposure or reduce risk to as low as reasonably practicable.

All of this would be in the employer's documented, implemented and audited Electrical Safety Program.

Correct me if I'm wrong but I believe the idea that you can close a breaker without PPE under "Normal Operation" conditions is a misconception. NFPA 70E article 110.4(D) states Normal operation of electric equipment is permitted if a normal operating condition exists. Not that PPE isn't required. To clarify further, this statement is under section 110.4 (Energized work) which is listing examples of when energized work is permitted. Therefore this article is giving permission to perform "energized work" without a permit under Normal Operation conditions, not saying you don't need PPE.

Thanks!

What 110.4 is stating (110.2(B) in 2024) is that you can perform "normal operations" of the equipment inside the limited approach boundary if equipment meets the criteria for "normal operating condition" (properly installed, maintained, covers closed, etc.) without the need to place the equipment in an electrically safe work condition. In other words, if you are interacting with equipment but not "working on" it, you can do so leaving it energized. Now what is a "normal operation" for a circuit breaker? Definitely not racking them in or out, but where the confusion comes from is some people would consider opening and closing a normal operation while others might not (I would argue it is a normal operation if it is stated by the manufacturer to be such).

We can get some clarification from the section detailing Arc Flash Risk Assessments, Table 130.5(C) (2024) which estimates the likelihood of an arc flash event, which allows us to "determine if additional protective measures are required, including the use of PPE" 130.5(A)(3) (2024)
This table lists "removal or installation of a circuit breaker" as always being likely for an arc flash event to occur. Is lists "operation of a circuit breaker" as being likely for an arc flash event to occur under abnormal operating conditions, and not likely to occur under normal operating conditions.

Bottom line being, you need to do the arc flash risk assessment before working on equipment and decide for yourself. If you determine the equipment to be in "normal operating condition" and you determine opening a breaker to be a "normal operation", then yes you can do so without putting the equipment in an electrically safe work condition and without wearing PPE and still be following 70E. That being said, a one size fits all determination of "70E says we don't need PPE to open breakers" is not correct either, you need to do the risk assessments every time and make the determination on every piece of equipment before you interact with it if you are going to go that route. I instruct my electricians to just always wear PPE to the incident energy level to open/close breakers, or use a remote switch if available. That is due to my own risk assessments and decision to make it a standard electrical safe work practice at my facility.