Electrical Switch gear guarding 1

[tladams]

Hi All
I need some assistance with a little disagreement.
During a recent inspection by a co-worker from another facility , he said that I need to guard the 440 volt switch gear that was installed in a new addition.
I have contacted the electrical designer and the electrical contractor that installed the service and they could not provide me with any documentation that indicates that I do/or do not need to guard the equipment.
I have not been able to find any standards anywhere that says I do or do not have to put a fence and guard the switch gear.
So my question is " In an industrial (Manufacturing)setting am I required to place a fence or other guard around the 480 volt 3 phase switch gear.
Please include any references that apply.
Thank you for your assistance
TLA

 

[ScottyUK]

What hazard is the guard protecting against? It is difficult to imagine that anyone would be installing open frame equipment in this century, so I'll assume that it is conventional dead front metal-clad gear with all the components behind closed covers, so direct contact with live electrical conductors is pretty much ruled out. After that, it is diffcult to say without knowing what legalislation you are governed by, and what environment the equipment is located in.

 

[crshears]

Good point, Scotty; without knowing the hazard, it's hard to answer the query. Someone here uses the tagline 'an undefined problem has an infinite number of solutions,' or words to that effect; and in this situation, it's apropos.

TLAdams, it might be helpful to ask what your co-worker thought the switchgear needed guarding from...after all, if such a statement is made, some qualifiers to clarify why might be useful. Make him spell it out.

Two-ton forklifts that could flatten it? Probably. Employee-only foot traffic? Not a huge amount of hazard there...you get the idea.

 

[tladams]

Thank you for the reply's so far
First I am in the State of Michigan and yes the switch gear is the dead front
The co-worker is trying to prevent an unauthorized someone from turning a switch off and creating an arc flash.
There are some pallets stored near this switch gear but we maintain the 36" of clearance at all times and the area of the switch gear is marked off to identify the required operating clearance.
My co-worker has referenced OSHA's general duty clause and tried to reference the life safety code , and the NEC. But at all times he could not reference any specific book chapter and section.
He also made a statement that someone could put the forks thru the face of the switch gear as was mentioned above but in that case a guard rail or fence is not going to stop, it may slow the for truck down but not stop it.
Please feel free to ask more questions and please understand that I am looking for specific code requirments that would indicate that the need for the guards and or fence.
Thank you again
TLAdmas

 

[catserveng]

So in the OSHA General Duty Clause,

1926.403(j)(2)(ii)

Installations accessible to unqualified persons. Electrical installations that are open to unqualified persons shall be made with metal-enclosed equipment or shall be enclosed in a vault or in an area, access to which is controlled by a lock. Metal-enclosed switchgear, unit substations, transformers, pull boxes, connection boxes, and other similar associated equipment shall be marked with appropriate caution signs. If equipment is exposed to physical damage from vehicular traffic, guards shall be provided to prevent such damage. Ventilating or similar openings in metal-enclosed equipment shall be designed so that foreign objects inserted through these openings will be deflected from energized parts.

I just recently got into a similar discussion with a customer after two incidents at a site. First one, they had stored adjacent to the switchgear pallets and tubs, and during a late shift a forklift operator misjudged and crunched the back of the gear pretty good. Fortunately he did not cause a short (but came about as close as you could and still not). The state inspector referenced the above clause. The insurance adjustor for the end user was way less forgiving, not only did they not pay they claim, they also went thru the facility and came up with a huge list of things they thought they were doing wrong, and of course a much higher premium at renewal.

The second incident at site involved an "unqualified person", at the affected substation for this issue they had stored in the same area as the switchgear copy paper and office supplies, someone came in with a cart, loaded it up and on the way out banged into the switchgear and tripped two feeder breakers off line by hitting the handles. In itself not really a big problem, right? Except there was some kind of critical production run and when the breakers tripped the financial impact was pretty severe. Same insurance company inspector had even less humor on this one. I didn't get involved in all the conversations, actually I mainly just repaired one of the circuit breaker switches that got bent when he hit it. But the after effects seemed pretty far reaching, and in short, both CAL-OSHA and the insurance company had problems with having switchgear with exposed operators in areas where "unqualified persons" could both inadvertently operate equipment and do damage to it.

I don't have specific references, but you may want to also check with your insurance carrier and your local fire marshal. If you stack pallets near the switchgear then I'm pretty sure that meets the criteria for exposing the switchgear to vehicular traffic and at least barriers or bollards ought to be installed.

Hope that helps, Mike L.

 

[collies99]

Can one not get a door kit and lock it ?

 

[jraef]

The new requirements pertaining to the NFPA 70E may be playing a part in this as well. NFPA 70E deals with personnel safety around electrical equipment, most commonly associated with Arc Flash hazards. In the past, the rules said that the Hazard Risk Category (HRC) for performing tasks on or around the gear was HRC-0 (the lowest level) as long as your gear was closed, unless you have done your Arc Flash assessment and that says that the HRC is higher, even with the doors closed. They then went on to only SUGGEST that an Arc Flash assessment be done. So because doing the assessment could sometimes mean having to deal with a high HRC, people were foregoing the assessment. In the 2012 release, they fixed that by not only REQUIRING an assessment be done, but also now if you have NOT done an assessment, the HRC is now level 4, the HIGHEST. That means the person flipping a breaker handle on or off, even the janitor sweeping in front of the switchboard may need to be fully suited up in Arc Flash PPE to do their jobs.

OR... you control access to the equipment so that only "Qualified Electrical Workers" (as defined, documented and regularly tested in your plan) have access to it, OR you use equipment that is clearly labeled and certified as "Arc Resistant Equipment". Most people opt for the controlled access if at all possible, it's the least expensive option.

So is the NFPA 70E enforceable? Not really. But the way it works is that OSHA says that you MUST have a plan addressing worker safety around electrical equipment, the plan must be documented, executed and reviewed on a regular basis. They SUGGEST the NFPA 70E as a perfect example of an organized and executable plan, but stop short of actually requiring it. So you can come up with your own, but it had better be good. OSHA of course does not send out jack-booted thugs to inspect everyone's plans (contrary to popular belief), but IF there is ever an electrical accident the FIRST thing they will want to see is that plan and documentation. If you have faithfully followed NFPA 70E, you should be fine.

"Will work for (the memory of) salami"

 

[tladams]

Gentlemen
Thank you for your reply's. As I review them I see that I must not only enclose the switch gear in a fence to control access I also need to install a guard rail so as to prevent the potential of a reckless fork lift driver.
Are there any forms or other helps that are available to assist with the Arc Flash Assessment that I should preform.
I look forward to any additional comments and thank you again for your input.
TLAdams

 

[jraef]

Get a copy of the NFPA 70E, it outlines a very thorough process of evaluation, execution, documentation and testing requirements. If you don't want to take it on yourself, there are plenty of contract service providers that will come in and do it all for you.

"Will work for (the memory of) salami"

 

[ScottyUK]

Quick aside -

"...even the janitor sweeping in front of the switchboard may need to be fully suited up in Arc Flash PPE to do their jobs."

Some of us in European companies are following NFPA70E in the absence of any European equivalent to follow. Is the comment regarding the janitor real? I'm asking because at our site we use PPE for switching activities and racking in / out on our non-arc-contained gear, but not for general access to switchrooms and substations. Many routine tasks would be virtually impossible if all were performed while wearing a Cat 4 suit. I've worn both 40 Cal and 100 Cal suits, and I wouldn't fancy sweeping the switch house floor or cable pulling in either of them. We're not mandated to follow NFPA guidelines, but as a prudent operator we are trying to minimise risk to our people so the NFPA position is of interest.

 

[jraef]

Honestly, it was a bit of a stretch to illustrate a point about paying attention to the details. But technically, work performed within the Arc Flash Boundary must have a Hazard Risk assigned to it based on the available arc flash energy and the type of risks associated with the task. If you are just pushing a broom in front of a piece of switchgear and not actually interacting with it, the task based component of that risk is very low. But if the available energy inside is very high, that portion of the risk assessment may put the janitor into a level of HRC that he may not be used to, i.e. even if it goes from 0 to 1, he now has to be wearing eye protection, leather gloves etc. Then if you have ventilated gear, where does the AFB stop? Simplistic calculations say at the front of a closed door, but if that door is full of holes to allow air flow, why is the danger going to be decreased? My point was, you can no longer just assume anything, you have to DETERMINE if there is a hazard or not by doing an assessment. If your assessment of the risk of a janitor pushing a broom in front of high energy gear places him at a risk greater than 0, it must be addressed.

"Will work for (the memory of) salami"

 

[dpc]

In general, with no exposed live parts, NFPA 70E does not require PPE unless someone is interacting with the equipment in some way.

That said, some facilities require PPE to be worn to enter an electrical room but there is no direct requirement for this in NFPA 70E Most US industrial facilities we deal with require electricians to wear arc-rated shirt and pants at all times. Additional PPE is added as needed.