clearance in front of a disconnect.......

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qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
does the 3' rule for clearance in front of a panel apply
to a 100 amp fused disconnect as well? i want to put
a disconnect on the side of a transformer, and i've got
2'7" or so......

Being fused I would say it applies.
 

kwired

Electron manager
Location
NE Nebraska
110.26(A) just says

"and likely torequire examination, adjustment, servicing, or maintenance
while energized shall comply with the dimensions of
110.26(A)(1), (A)(2), and (A)(3) or as required or permitted
elsewhere in this Code."

If you can convince the AHJ none of that is likely then the clearance wouldn't be necessary. Most AHJ consider any such equipment to meet those conditions though, some relax the requirement if there is no overcurrent devices in said enclosure, but as is written is a little hard to exempt a junction box with splices from the requirements as one may want to take voltage or current measurements in that box which fulfills the examination part.
 

mwm1752

Senior Member
Location
Aspen, Colo
110.26(A) just says

"and likely torequire examination, adjustment, servicing, or maintenance
while energized shall comply with the dimensions of
110.26(A)(1), (A)(2), and (A)(3) or as required or permitted
elsewhere in this Code."

If you can convince the AHJ none of that is likely then the clearance wouldn't be necessary. Most AHJ consider any such equipment to meet those conditions though, some relax the requirement if there is no overcurrent devices in said enclosure, but as is written is a little hard to exempt a junction box with splices from the requirements as one may want to take voltage or current measurements in that box which fulfills the examination part.[/QUOTE]

Whats the easiest way to test a recess can--while energized -- Does it operate at 600v or less -- yes --- Am I being absurd - obviously -- Does it have to energized - no

I find it easy to exempt J boxes since the code only requires them to be accessible. If you cannot shut down a fused disconnect from a readily accessible OCD you are likely to test/repair/replace equipment while energized. Every circumstance has a unique set of issues -- The AHJ can have final say and it does not hurt to ask (at least not here)
 

kwired

Electron manager
Location
NE Nebraska
110.26(A) just says

"and likely torequire examination, adjustment, servicing, or maintenance
while energized shall comply with the dimensions of
110.26(A)(1), (A)(2), and (A)(3) or as required or permitted
elsewhere in this Code."

If you can convince the AHJ none of that is likely then the clearance wouldn't be necessary. Most AHJ consider any such equipment to meet those conditions though, some relax the requirement if there is no overcurrent devices in said enclosure, but as is written is a little hard to exempt a junction box with splices from the requirements as one may want to take voltage or current measurements in that box which fulfills the examination part.[/QUOTE]

Whats the easiest way to test a recess can--while energized -- Does it operate at 600v or less -- yes --- Am I being absurd - obviously -- Does it have to energized - no

I find it easy to exempt J boxes since the code only requires them to be accessible. If you cannot shut down a fused disconnect from a readily accessible OCD you are likely to test/repair/replace equipment while energized. Every circumstance has a unique set of issues -- The AHJ can have final say and it does not hurt to ask (at least not here)
Well other then the service equipment you can shut down pretty much everything else from a readily accessible OCD if things are installed to code some instances you can even shut down the service equipment - the section needs some work, as written one could interpret it to mean that clearance is needed for just about anything.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
Well other then the service equipment you can shut down pretty much everything else from a readily accessible OCD if things are installed to code some instances you can even shut down the service equipment - the section needs some work, as written one could interpret it to mean that clearance is needed for just about anything.
That is true. We run into clearance problems a lot because of our customers trying to put 10 pounds of something in a 5 pound bag.
 

mwm1752

Senior Member
Location
Aspen, Colo
Sometimes the branch circuit OCD for the feeder disconnect is inside a structure with locked entrances making the OCD not readily accessible is service work is to be performed. True with access to the structure all OCD would have ready access. It is less likely to shut down the entire service to perform testing. I'm sure we could debate this and both switch sides just to keep it intresting but the focus should be on whether it is safe or not.
 
That is true. We run into clearance problems a lot because of our customers trying to put 10 pounds of something in a 5 pound bag.
Here in our facility (the Island of Misfit Toys), clearance is a constant battle. I've been down this road so many times, it become acceptable in the current age of technology that "clearance", to those who punch computer keys and come up with floor plans, includes just enough space to get your cell phone into to take a picture of the fuse sizes, 'cause you sure ain't getting your hands and head in there.

As the statute is written, I take it mean anything that needs to be accessible for service, whether that service is pulling wire, checking voltage, changing fuses, repairing a latch, etc. If it has a cover and there's a possibility one would need to EVER access the innards, it should have 3' (in a perfect world). Personally, I very seldom get access to that luxury because people who draw never have to work inside the hell they've created.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
Here in our facility (the Island of Misfit Toys), clearance is a constant battle. I've been down this road so many times, it become acceptable in the current age of technology that "clearance", to those who punch computer keys and come up with floor plans, includes just enough space to get your cell phone into to take a picture of the fuse sizes, 'cause you sure ain't getting your hands and head in there.

As the statute is written, I take it mean anything that needs to be accessible for service, whether that service is pulling wire, checking voltage, changing fuses, repairing a latch, etc. If it has a cover and there's a possibility one would need to EVER access the innards, it should have 3' (in a perfect world). Personally, I very seldom get access to that luxury because people who draw never have to work inside the hell they've created.

They should be given the opportunity and not be allowed to turn it off.
 
One of my favorite pet peeves.

Note that the clearance required depends on the voltage to ground. In a device with 480v circuits, that is normally 277 and the clearance required is 42", not 36". In the case of two devices face to face with 480v circuits, the requirement is 48". Table 110.26(A)(1).

I see these violated all the time by people who believe that 36" is a universal requirement.

I mostly deal with industrial control panels. I wonder when the code will catch up with modern component designs which have virtually eliminated "exposed live parts" in a control panel. Most of the panels I deal with require a tool to reach a live terminal now. I wouldn't call that exposed but I don't want to argue with the AHJs about it so we treat all panels as though they have exposed live parts.
 

kwired

Electron manager
Location
NE Nebraska
One of my favorite pet peeves.

Note that the clearance required depends on the voltage to ground. In a device with 480v circuits, that is normally 277 and the clearance required is 42", not 36". In the case of two devices face to face with 480v circuits, the requirement is 48". Table 110.26(A)(1).

I see these violated all the time by people who believe that 36" is a universal requirement.

I mostly deal with industrial control panels. I wonder when the code will catch up with modern component designs which have virtually eliminated "exposed live parts" in a control panel. Most of the panels I deal with require a tool to reach a live terminal now. I wouldn't call that exposed but I don't want to argue with the AHJs about it so we treat all panels as though they have exposed live parts.
When working in these panels where nothing is "exposed" are you still required to wear appropriate PPE? IMO the hazards are still there especially if it is deemed you still need to wear PPE. Wearing that additional PPE likely impairs your mobility some and is even more reason IMO to have appropriate working spaces.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I am not 100% convinced that so called "fingersafe" components eliminate the hazard from voltages that might be present on terminals.

I do think there are effective ways to guard live components so just being inside a cabinet does not expose one to hazardous voltages. However, they tend to make it difficult to actually do anything useful in the cabinet.

A better idea is to use lower voltages wherever possible that by definition are not considered hazardous. This is often a more cost effective design anyway.
 
When working in these panels where nothing is "exposed" are you still required to wear appropriate PPE? IMO the hazards are still there especially if it is deemed you still need to wear PPE. Wearing that additional PPE likely impairs your mobility some and is even more reason IMO to have appropriate working spaces.
This comes up all the time here. I cannot cite the documentation, but I'm posititve the answer is yes, given that the goal is protection from arc flash and proper lock out tag out and/or troubleshooting. Shock doesn't really factor in AFAIK. Maybe others can shed more light, but "finger safe is not a replacement for 70 E protection to my knowledge.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
... "finger safe" is not a replacement for 70 E protection to my knowledge.
One of the things that comes up often in solar PV systems (DIY) is that finger safe fuse holders are often not listed for load breaking (at least at DC) and so are no substitute for a breaker or switch.
Major arcing!
 
Just to Throw Another Wrench in the Box!

Just to Throw Another Wrench in the Box!

What about Conduit Bodies with Splices?

I know this silly, but how far are we going to take it. :happysad:

110.26(A) just says

"and likely torequire examination, adjustment, servicing, or maintenance
while energized shall comply with the dimensions of
110.26(A)(1), (A)(2), and (A)(3) or as required or permitted
elsewhere in this Code."

If you can convince the AHJ none of that is likely then the clearance wouldn't be necessary. Most AHJ consider any such equipment to meet those conditions though, some relax the requirement if there is no overcurrent devices in said enclosure, but as is written is a little hard to exempt a junction box with splices from the requirements as one may want to take voltage or current measurements in that box which fulfills the examination part.[/QUOTE]

Whats the easiest way to test a recess can--while energized -- Does it operate at 600v or less -- yes --- Am I being absurd - obviously -- Does it have to energized - no

I find it easy to exempt J boxes since the code only requires them to be accessible. If you cannot shut down a fused disconnect from a readily accessible OCD you are likely to test/repair/replace equipment while energized. Every circumstance has a unique set of issues -- The AHJ can have final say and it does not hurt to ask (at least not here)
 

kwired

Electron manager
Location
NE Nebraska
What about Conduit Bodies with Splices?

I know this silly, but how far are we going to take it. :happysad:

Correct, and like many have said before this section needs overhauled to better clarify it's intentions, there is no limitation on just how far to take it as it is written, and in today's lawsuit happy society, it is not all that silly either.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I am one of those that says as it is currently written it applies to everything...the kitchen counter receptacles required by 210.52 create a violation of 110.26.
 

kwired

Electron manager
Location
NE Nebraska
I am one of those that says as it is currently written it applies to everything...the kitchen counter receptacles required by 210.52 create a violation of 110.26.
That can be corrected - use a 36 inch deep counter top, but you would need to raise any upper cabinets above the receptacles so they are 6-1/2 feet above the counter, and since width of working space is 30 inches plus factor in kitchen counter outlet spacing rules, pretty much all upper cabinets would need raised - and even with no upper cabinets minimum ceiling height from the floor would typically need to be 9.5 feet.
 
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