AC Disconnect Location

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eric9822

eric9822

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Location
Camarillo, CA
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Electrical and Instrumentation Tech
We have an AC unit with a local disconnect located behind a control room in an industrial facility. A recent installation in close proximity has rendered the disconnect inaccessible so we are going to move it. The problem is that there really isn't a good spot to move it to nearby. One proposal is to move it to the edge of the roof of the control room directly above the AC unit. The roof is accessable via a permanently attached OSHA compliant ladder and the area adjacent to the disconnect would have railings to prevent someone from falling off. I am not sure this would meet the requirements of 440.14 for a "readily accessible" disconnect. If our own employees were servicing the equipment I think we could eliminate the local disconnect altogether by using the exception noted in 440.14. The AC is serviced by contractors so I am not comfortable removing the local disconnect. We are still following the 2005 NEC. Opinions?
 
George Stolz said:
Your description is a little confusing. Is the disconnect going to be on the same floor as the unit? :-?
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Sorry. No, The AC unit is on the ground and the proposed disconnect location is on the roof of a building. They would be within sight of each other and about 15 feet apart. Thanks.
 
eric9822 said:
The roof is accessable via a permanently attached OSHA compliant ladder. . . .
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Since you are not talking about a "portable ladder," I believe this would qualify as "readily accessible," in accordance with the article 100 definition of that phrase. So I think this is an acceptable solution.
 
eric9822 said:
Sorry. No, The AC unit is on the ground and the proposed disconnect location is on the roof of a building. They would be within sight of each other and about 15 feet apart. Thanks.
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This is a little bit of a grey area in my opinion. Clearly if you needed to resort to a portable ladder then the disconnect would not be readily accessible but if the ladder is permanently attached then it would be up to the AHJ to determine if it was readily accessible or not.

I could see this going either way.

Chris
 
I see it clear as mud. :) I would check with the AHJ since it is an odd situation. Personally I think it is okay. I would mark the unit as to where the disco is for clarity.
 
I see it as completely clear. The definition of readily accessible explicitly excludes portable ladders. That tells me that permanent ladders are OK.
 
Let me play devils advocate for a moment.

Would climbing up a ladder and over a parapet to get to a disconnect be "Climbing over an obstacle"?

Chris
 
Thanks for all the input. I was on the fence but I won't object to it's placement on the roof if no other suitable place is found.
 
raider1 said:
Would climbing up a ladder and over a parapet to get to a disconnect be "Climbing over an obstacle"?
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It might. Depends on how the (permanent) ladder allows you to get past the parapet. If you simply step off the ladder and onto the roof, using the parapet (or in this case, the railing) as a hand-hold on your way past it, then it is not "climbing" over an obstacle. Since we are talking about an "OSHA compliant" permanent ladder, I am sure that you don't get to the top of the ladder and then have to use your climbing skills to get over the parapet.
 
Let me continue playing devils advocate.;):)

Where is the ladder located in relationship to the A/C unit?

What if the ladder was located on the other side of the building, would that make the disconnect not quickly reached for operation, renewal, or inspections?

Chris
 
raider1 said:
Let me continue playing devils advocate.;):)

Where is the ladder located in relationship to the A/C unit?

What if the ladder was located on the other side of the building, would that make the disconnect not quickly reached for operation, renewal, or inspections?

Chris
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If you have to climb you are going over an obstacle. Not being cute IMO this would not be readily accessible.
 
raider1 said:
What if the ladder was located on the other side of the building, would that make the disconnect not quickly reached for operation, renewal, or inspections?
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No. It might make it "not quickly reached" from the location of the AC unit. But since it is required to be readily accessible from the location of the AC uint, that would create a violation. Happily, that is not the case in the present situation. :grin:
 
One-eyed Jack said:
If you have to climb you are going over an obstacle. Not being cute IMO this would not be readily accessible.
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Nothing prohibits climbing. All that is prohibited is having to climb a portable ladder. I suppose that is because if you have to look around to find a ladder, you will have lost the "quickly" part of the process. But if the ladder is permanently installed, you don't have to look around to find it. It is no different than having to climb a stair or a flight of stairs. Neither is prohibited by the definition of "readily accessible."
 
charlie b said:
No. It might make it "not quickly reached" from the location of the AC unit. But since it is required to be readily accessible from the location of the AC uint, that would create a violation. Happily, that is not the case in the present situation. :grin:
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Thats why I said I was playing devils advocate.:)

Chris
 
eric9822 said:
We have an AC unit with a local disconnect located behind a control room in an industrial facility. A recent installation in close proximity has rendered the disconnect inaccessible so we are going to move it.
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First question that comes to mind is, if the recent installation has rendered the disconnect inaccessible, what effect on the accessiblity to the line terminations and controls of the unit does this create? As for the ladder problem, personally I would question whether you could reach the disconnect quickly for operation.
 
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In my case there is no parapet and the ladder is about four feet to the right of the AC unit and the disconnect would end up directly above the AC unit. If there was a parapet I don't believe it would be an obstruction because as all our ladders to roofs with parapets extend to a landing even with the top of the parapet. If the parapet obstructed the view of the disconnect from the AC unit then a violation of 440.14 would exist.
 
gmeerschaert said:
First question that comes to mind is, if the recent installation has rendered the disconnect inaccessible, what effect on the accessiblity to the line terminations and controls of the unit does this create? As for the ladder problem, personally I would question whether you could reach the disconnect quickly for operation.
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The AC terminations and controls are still accessible. The disconnect is only used for lockout purposes so I am not sure quick access is really required.
 
Given that, as long as both the disconnect and unit were clearly/permanently identified, your subcontractors are trained and signed off on your Lock Out/Tag Out procedures (OSHA requirement) the location should be fine.
 
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