480V Electrical Enclosure Doors Open While Energized

JasonC.

Member
Location
Massachusetts
Occupation
Controls Technician
Hi guys. I work in a beverage facility as a controls technician and I have a question about leaving doors open on energized electrical enclosures. I am by no means a qualified electrician. I've done some digging around OSHA and NFPA 70E guidelines and a bit online but haven't really found a definitive answer. Though, those seem hard to come by when it comes to electrical safety. Or safety in general.

A couple times now we've been told that we can leave the doors open on 480V supplied electrical enclosures because the AC units have failed and high temperatures will cause something in the enclosure to fail. IE: VFD's or a PLC. To make this safe, the limited approach boundary is blocked off with caution tape, the doors left open and usually a fan is set up to move some air around. The best I can find is OSHA 1926.403(i)(2) . But this is focused around construction guidelines so I'm not sure it applies.

My main concern is that there's operators working around some of these enclosures and they may not realize how dangerous those panels can be. Hoses are commonly used during cleaning and water ends up getting just about everywhere. The last thing I want to see is someone get hurt.

In my mind, the correct thing to do would be to get spare parts or units to fix or replace the AC units when something goes wrong with them. And then the enclosures never need to be left open. But unfortunately, this doesn't seem to be happening and it's becoming more acceptable for us to leave doors open. A while back a 480V panel was left open for weeks with caution tape and a sign stating only qualified personnel could enter before the AC unit was finally repaired. So, I'm hoping to find some information that I can use to push back on this. Or if I'm wrong, that's fine as well, but at least I'll know for sure.

Thanks for any help,

Jason
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
No, this is not safe at all. They either need to install some fan inside or find out why temps are so high. Call osha...lol they will get a fine so high they will never do that again
 

JasonC.

Member
Location
Massachusetts
Occupation
Controls Technician
Thanks for the replies. I agree that OSHA would likely have a field day with this but again, I'm hoping to find something that I can use to prevent this from happening in the future. I'd imagine OSHA would have to cite one of their guidelines in order to take any action and that's essentially what I'm looking for. I've already had conversations with a few people that could make the decision to stop allowing doors to be left open, but it seems to be one of those things that doesn't seem like a big deal. Until someone gets hurt. I'd very much prefer it doesn't get to that point though. I'd like to convince them that it's in their best interest to keep the doors closed.

Also, I apologize if it seemed like I was saying that the AC units aren't getting fixed at all. They do. But preventative maintenance would ensure that they're ready and working for the summer months. As it is right now, they get worked on when when they breakdown or are found to be broken down and we generally contract out for it. So, many of the parts we don't have in house. It can take a couple days for a unit to get fixed. Until then, the doors are being left open.

I spent some more time looking through OSHA electrical guidelines but much of the information I'm finding is either very specific and doesn't seem to apply or very vague and can be interpreted in a few ways.

Again, I appreciate any help or thoughts. Ultimately, I'm confident I can convince them that repairing the AC units before it's going to potentially cause an issue is the best course of action. But I also know that things tend to be forgotten about and in the future we'd likely run into the same issues again. Getting them to create a standard that leaving panel doors open is unacceptable is going to be a tougher battle and the more information I have, the better.

Thanks,
Jason
 

ValeoBill

Member
Location
Wasaga Beach, Ontario
Occupation
Industrial Electrician
As a factory electrician for many years, this type of situation does come up; usually during our hot humid summers. It wasn't until I became certified in health and safety that the answer came to me. Here in Ontario, Canada, the critical clause in our H&S regs is "the employer will do everything reasonable to protect the worker." It would seem reasonable to have some type of screening over the gap to prevent accidental contact. Even chicken wire would be better than just caution tape. If you want to rattle some cages, look for any court cases where an employer has failed in its duty to protect a worker. Here in Ontario, the fines can be levied against the owner, the factory manager and the shift supervisor. Having a spare A/C unit kicking around is a lot cheaper than these fines.
 

Gary Gagnon

Member
Location
49461
Occupation
Electrical tech
Yes it violates several articles of OSHA and the NEC. If you said there was a fairly solid barricade set up at the arc flash boundary, I would not be all that concerned, if it was a temporary thing, waiting to be corrected. There are several codes you could use. NFPA/NEC 70E, article 210.2 "Area Enclosures"... where required to guard against unauthorized access or unintentional contact with exposed conductors and circuit parts... 205.7 covers shall be in place with all associated fasteners and latches secured. OSHA 1910.303(g)(1)(vii)(B), 1910.303(h)(2)(iv), we can do this all day long. The guys above are correct, the company should modify the equipment to handle hot weather, not open up the controls to people and the elements to get by on the cheap.
 

JasonC.

Member
Location
Massachusetts
Occupation
Controls Technician
I ended up having a meeting yesterday with the managers at the facility and we're going to do just that. Increase the frequency that the AC units are PM'd to catch issues with them sooner and work on getting more parts in house to repair or replace them instead of waiting for parts. We're not going to leave panel doors open if they're in a high traffic area or where someone is expected to be consistently working. If we do ultimately decide that we have no other choice in a more isolated area, we're going to come up with a better, more permanent / solid barrier, isolate the area as best as possible and if someone that needs to access the area that isn't "qualified" to be working around an energized panel, we're going to require someone with the proper training to essentially escort them until the work is done to ensure they stay away from the panel. I couldn't quite convince them to make a policy to agree to never do it, but I think its a reasonable improvement none the less.

I ended up finding that NFPA/NEC defines that a disconnect that requires a tool to open a door while energized it's considered a safety interlock and specifically states that they can only be defeated by a qualified person with the appropriate PPE and only while work is being done. Then it must be put back in place and the original guards restored. So, leaving an unattended door open wouldn't be considered being actively worked on. And since most of our doors have badge readers to open them, there's really no way to lock the areas off.

I did speak to one of the electrical contractors we had on site the other day and he stated that the only way he thought we might get away with leaving doors open is to have an attendant at the panel actively letting people know to keep away the entire time the door was open. Otherwise we'd be open to OSHA fines. But best practice is to just not do it.

I appreciate all the replies and information you all shared. If anyone has any questions about the specific codes I found, I'll be happy to find them again and share them.

Thanks,
Jason
 

retirede

Senior Member
Location
Illinois
FWIW:
In a plant I worked in long ago, we replaced the washable, external filters on all cabinet air conditioners with disposable and instituted a monthly filter change program. Our A/C failures dropped to near zero.
 
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