Working Space and Floor Conveyors

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jvanthiel

Member
Location
Wisconsin
We are looking at a new machine installation. The machine has a larger footprint than the machine it is replacing, creating a space issue. We are looking at installing a floor exit conveyor for the machine that sits 12" above the floor surface adjacent to the machine. The conveyor is 5-6 feet wide and will bump up again the drive side of the machine - in front of two electrical panels. The panels are raised up, so there is no issue with the panel doors opening 90 degrees and the conveyor is wide and deep enough to meet the clearance requirements under 110.26 Spaces About Electrical Equipment. My question is this: can the conveyor itself (if locked out), be considered "working space"? Also - since the conveyor is an exit conveyor with product passing it for a few seconds every few minutes be considered "dedicated equipment space"? The panel will be temporarily blocked when product passes by, but otherwise clear.

When service or troubleshooting is conducted, the exit conveyor will be cleared and the conveyor locked out, so it will be like standing on an elevated work platform with a non-moving plastic surface. There will be no gap between the panel and the conveyor, so the electrician will have room to work without a tripping or egress issue.

Any help appreciated. I am using the NEC 2008 handbook, but the additional notes did not add any clarification for a situation like this.
 

tom baker

First Chief Moderator
Staff member
Wow that's a tough one. We often see equipment pads under switch gear that extend out in front 3-4". The code is just not clear on the floor in front of the equipment, if it has to be level, if so how level? We can't have stair way risers in front of service equipment but that's not in section 110.
Lets wait for some more comments.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I am having trouble understanding the situation, mostly because I am unfamiliar with some of the terms (e.g., "exit conveyor"). But I gather that if a person needs to work inside one of the panels, you will need to stop the transfer of materials using the conveyor, and lock out the conveyor. After that, the electrical worker will actually stand on the conveyor belt (or whatever that surface is called). When doing so, the electrical worker will be standing on a surface that is 12" above the floor, but that does allow full access to the inside of the panel. Do I have that right?

If that is right, then my answer is that it might be allowable. Some issues that come to mind include,

  • Is the conveyor belt (I will use that term for now) sturdy enough to support the weight of the electrical worker, even while that person is shifting their weight while doing work inside the panel?
  • You say there is no gap between the edge of the conveyor belt and the panel. Do you mean that there is no danger of the electrical worker stepping too close to the panel, so that their foot slips and they fall that 12" onto the floor surface?
  • Would the electrical worker have to bend down or even kneel, in order to be able to reach inside the panel?
 
Last edited:

Smart $

Esteemed Member
Location
Ohio
Non-compliant IMO.

110.26 Spaces About Electrical Equipment. Access and
working space shall be provided and maintained about all
electrical equipment to permit ready and safe operation and
maintenance of such equipment.

Any event requiring immediate access would be impeded and unsafe.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Non-compliant IMO.



Any event requiring immediate access would be impeded and unsafe.

what event would ever require immediate access?

many conveyors can be wheeled out of the way. if it can be moved how is this any different than when a panelboard is in a hallway and people are walking by? there is a brief period of time when someone is in the working space perhaps many times in a day.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Any event requiring immediate access would be impeded and unsafe.
Good point, but I do not agree. Panels are located in corridors, and people walk by them all the time. I can put a load onto a dolly and roll it past a panel without causing a code issue. My point is really that "immediate access" is not a requirement. For example, we don't need to be able to quickly open a breaker to terminate a shock incident. There is nothing "life-safety" related about gaining access to the panel. The safety consideration at stake, when we talk about working clearance, has to do with a worker setting up the work site, bringing in the tools, removing the panel door, and doing the work. This is not a time-critical event. It does not require "immediate access." I think there is a big difference between rolling the dolly past a panel as opposed to leaving it right in front of the panel for any period of time. I think the entire purpose of forbidding storage in front of a panel is to prevent the worker from being tempted to say, "heck, I'll just be in the panel for a few moments, so I won't bother moving this file cabinet out of my way."
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
OK, Bob, that was unfair of you to type a short answer that says some of the same things I wanted to say as I was typing my longer answer. :happyno:
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
A temporary platform that could span the conveyor might not improve code compliance, but it would make the electricians job easier.
 

Smart $

Esteemed Member
Location
Ohio
what event would ever require immediate access?

many conveyors can be wheeled out of the way. if it can be moved how is this any different than when a panelboard is in a hallway and people are walking by? there is a brief period of time when someone is in the working space perhaps many times in a day.

Good point, but I do not agree. Panels are located in corridors, and people walk by them all the time. I can put a load onto a dolly and roll it past a panel without causing a code issue. My point is really that "immediate access" is not a requirement. For example, we don't need to be able to quickly open a breaker to terminate a shock incident. There is nothing "life-safety" related about gaining access to the panel. The safety consideration at stake, when we talk about working clearance, has to do with a worker setting up the work site, bringing in the tools, removing the panel door, and doing the work. This is not a time-critical event. It does not require "immediate access." I think there is a big difference between rolling the dolly past a panel as opposed to leaving it right in front of the panel for any period of time. I think the entire purpose of forbidding storage in front of a panel is to prevent the worker from being tempted to say, "heck, I'll just be in the panel for a few moments, so I won't bother moving this file cabinet out of my way."
What events require immediate access is moot. Code says "ready and safe operation". I'm not going to try and influence how you interpret that.

Panelboard in a hallway is a valid argument... but people will move themselves or walk around you if you are accessing the panelboard. Counterpoint: Would you install a panelboard immediately to one side of a moving walkway?

Just as not having to move a file cabinet, I can see someone saying "I'll just hop on the conveyor to flip the breaker. It'll only take a sec'."
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
What events require immediate access is moot. Code says "ready and safe operation". I'm not going to try and influence how you interpret that.

Panelboard in a hallway is a valid argument... but people will move themselves or walk around you if you are accessing the panelboard. Counterpoint: Would you install a panelboard immediately to one side of a moving walkway?

Just as not having to move a file cabinet, I can see someone saying "I'll just hop on the conveyor to flip the breaker. It'll only take a sec'."

you are the one that suggested immediate access is required.

something that is permanently in the way is a lot different than something temporarily in the way.

I understand that over the last few years there has been an entire industry spawned to draw yellow lines on floors in front of panel boards.

can you hide a panelboard by putting a calendar over it? how does that impede access to the equipment?
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Just as not having to move a file cabinet, I can see someone saying "I'll just hop on the conveyor to flip the breaker. It'll only take a sec'."
Another good point. :happyyes: It is best to do all electrical work with the panel turned off and locked out. But now you also need to turn off, and lock out, another piece of equipment that is not directly related to the panel. This could well be a sticking point for the AHJ.
Counterpoint: Would you install a panelboard immediately to one side of a moving walkway?
I'll only give you a "nice try" on this one. ;) Moving walkways have moving handrails, and you would need the panel to be at least 3 feet away from that thing.
 

Smart $

Esteemed Member
Location
Ohio
you are the one that suggested immediate access is required.

something that is permanently in the way is a lot different than something temporarily in the way.

I understand that over the last few years there has been an entire industry spawned to draw yellow lines on floors in front of panel boards.

can you hide a panelboard by putting a calendar over it? how does that impede access to the equipment?
Debating what obstructions are and are not compliant will not have any resolution. Code does not state any criteria. If you take this requirement to the nth degree, nothing is permitted inside the work area except persons and accessories required to perform "ready and safe operation or maintenance of such equipment." Anything else would be a leniency not written into the requirement.
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
I would fail it. Access isn't maintained if you have to shut off a conveyor to get to the panels.

Second reason - I just don't see a conveyor as being a sturdy or solid enough structure to stand on and work on to qualify as dedicated working space. It has to have either belts or rollers, and I can't imagine standing on that and trying to work on something hot.
 

Smart $

Esteemed Member
Location
Ohio
...
I'll only give you a "nice try" on this one. ;) Moving walkways have moving handrails, and you would need the panel to be at least 3 feet away from that thing.
I'll accept a "nice try" commendation as it was just something that popped into my head with the mention of a panelboard in a hallway without considering ramifications stemming from the handrails... but what if it were a wide moving walkway and the panelboard was inside the handrail on one side and still provided 3' of clearance to the other handrail. Obviously a panelboard would never be installed in this location... but just from a Code "Spaces About Electrical Equipment" perspective, would you say such a scenario is or isn't compliant?
 

pfalcon

Senior Member
Location
Indiana
Sorry Charlie, I'm with the smart money on this one.

5'-6' exit conveyor implies large loads. During service requirements a load may be in place directly in front of the panel. Much more likely if the panel is controlling part of the conveyor itself as is likely in this case.

I accept that transient loads (e.g. people) are okay. But conveyors are considered queued storage devices. They are expected to have stationary periods. If the shop is honest they'll probably admit packing that conveyor full when a downstream operation faults.

..., "heck, I'll just be in the panel for a few moments, so I won't bother moving this file cabinet out of my way."

Or in this case that could very well be a load that occupies a 6' wide conveyor and requires a fork lift to move.
 

iwire

Moderator
Staff member
Location
Massachusetts
I don't beleive I have meet any electrical inspector that would be good with this idea. I would fail it if I was the EI.
 

kwired

Electron manager
Location
NE Nebraska
I would fail it. Access isn't maintained if you have to shut off a conveyor to get to the panels.

Second reason - I just don't see a conveyor as being a sturdy or solid enough structure to stand on and work on to qualify as dedicated working space. It has to have either belts or rollers, and I can't imagine standing on that and trying to work on something hot.
Conveyor can be a pretty generic term, if it is an enclosed conveyor of some sort and has a non moving top with required space- no problem in my book, but most of us are basing replies on an open belt or similar conveying machine. I am with the crowd that wants to reject that particular situation - there may be sufficient safe working space in front with a stopped conveyor, but what if a load on the conveyor happens to stop in the working space? What if there is a breakdown with a load in the work space and that load is not something easily moved by the worker without the use of tools or machines?
 

iwire

Moderator
Staff member
Location
Massachusetts
A conveyor is not grade, floor or platform so it is a violtion.



(3) Height of Working Space. The work space shall be clear and extend from the grade, floor, or platform to the height required by 110.26(E). Within the height requirements of this section, other equipment that is associated with the electrical installation and is located above or be-low the electrical equipment shall be permitted to extend not more than 150 mm (6 in.) beyond the front of the electrical equipment.

You might be able to build a platform over it and satisfy the rules but I think it is very clear both OSHA inspectors and EIs would have a real issue with having to stand on a conveyor to access a panel.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
A conveyor is not grade, floor or platform so it is a violtion.





You might be able to build a platform over it and satisfy the rules but I think it is very clear both OSHA inspectors and EIs would have a real issue with having to stand on a conveyor to access a panel.

This I agree with.

I think if it can be moved readily, it does not impede the necessary access and working space though.
 

jvanthiel

Member
Location
Wisconsin
Clarification

Clarification

Guys,

I appreciate the discussion on this and I wanted to clarify a few points that were being discussed:

1. This is a corrugated conveyor. It takes stacks (units) of finished boxes and moves them to shipping. Units never stop on this conveyor - once the unit of finished product leaves the machine the unit moves along this conveyor onto another section (running perpendicular) of conveyor that takes it to shipping. There should never be units standing in front of these panels unless the conveyor is broken, which would require access to the conveyor and/or the conveyor panel which is in another area.
2. The electrical panels in question are for the converting machine making the boxes that will be exiting on the conveyor. The conveyor can be locked out from the underside of the conveyor before stepping on it. I attached a picture of the conveyor in question. It is actually designed for people to walk on to put tags on the corrugated units. It is like standing on hard plastic. There is no give.
3. There would have been a 1' of floor space between the panel and the conveyor, so we are putting in a solid platform to fill that gap and bring the entire work surface 6' out from the panel to the same work height. Employees would not have to bend down to work in the panels, they would still be at midsection height.

Thanks again. My background is in Environmental Health and Safety. I appreciate the insights of those with direct practical experience.
 

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