110.26 (A) (1) Working Spaces

[Gary11734]

I need clarification from the experts here.

An inspector turned down an electrical room for violation of working space.

He says the switchboards have live parts on each front side so this would be condition 3 of Table 110.26(A)(1). (They are both serviced from the front)

I never thought about this until this came up.

My first thought would be; If I only work on one switchboard at a time, you would be under condition 2 because you would have live parts on one side and grounded parts on the other. This would put me in condition 2 as opposed to condition 3 which now is the violation.

What do the experts say here based on their interpretation of the intent of the code?

 

[jim dungar]

... If I only work on one switchboard at a time, you would be under condition 2 because you would have live parts on one side and grounded parts on the other. This would put me in condition 2 as opposed to condition 3 which now is the violation....

I agree.

 

[infinity]

My first thought would be; If I only work on one switchboard at a time, you would be under condition 2 because you would have live parts on one side and grounded parts on the other. This would put me in condition 2 as opposed to condition 3 which now is the violation.

Where is that in the NEC?

 

[kwired]

Is this new or are you replacing something existing?

see 110.26(A)(1)(c):

Existing Buildings. In existing buildings where electrical equipment is being replaced, Condition 2 working clearance shall be permitted between dead-front switchboards, switchgear,^ panelboards, or motor control centers located across the aisle from each other where conditions of maintenance and supervision ensure that written procedures have been adopted to prohibit equipment on both sides of the aisle from being open at the same time and qualified persons who are authorized will service the installation.

In new installations I don't see you have any choice - you need condition 3 clearances.

In existing installations you need qualified persons and written procedures or you still are using condition 3 clearances.

 

[infinity]

Is this new or are you replacing something existing?

see 110.26(A)(1)(c):

In new installations I don't see you have any choice - you need condition 3 clearances.

In existing installations you need qualified persons and written procedures or you still are using condition 3 clearances.

 

[Gary11734]

Is this new or are you replacing something existing?

see 110.26(A)(1)(c):



In new installations I don't see you have any choice - you need condition 3 clearances.

In existing installations you need qualified persons and written procedures or you still are using condition 3 clearances.

Note: this is a new installation based on the 2014 Code...


I see your point on (c). So, they are waving the normal requirement, (worst scenario) for existing conditions in old buildings. I should not have to infer from one article, (existing buildings) to make another code rule (new buildings) valid.

I never thought of the worst-case scenario was the norm in dealing with the code in working spaces. The equipment should be maintained by Authorized Personnel only so this would make this a valid argument. Old buildings that have condition 2 (live, non-live based on if you have both covers off) installed makes my point. It was probably passed based on that argument.....



Thanks for all the replies... Gary

 

[kwired]

Note: this is a new installation based on the 2014 Code...


I see your point on (c). So, they are waving the normal requirement, (worst scenario) for existing conditions in old buildings. I should not have to infer from one article, (existing buildings) to make another code rule (new buildings) valid.

I never thought of the worst-case scenario was the norm in dealing with the code in working spaces. The equipment should be maintained by Authorized Personnel only so this would make this a valid argument. Old buildings that have condition 2 (live, non-live based on if you have both covers off) installed makes my point. It was probably passed based on that argument.....



Thanks for all the replies... Gary

They have no conditions that allow you to go from condition 2 clearance to condition 1 clearance.

Maybe this is only allowed because if changing out existing gear and your old gear had nearly exact clearance allowed, new gear that is slightly larger might not allow enough clearance??

I see no reason to allow such change for new construction, there you have better opportunity to design accordingly. If you are pushing the limits at design stage and end up with larger gear than initially expected you have a major problem if your inspector is enforcing what NEC says, so on that new construction one should allow plenty of clearance, but the architects seem to always want to only give you as little space as possible.

Regardless what you or I like or dislike about it - it says what it says.

 

[jim dungar]

I should not have to infer from one article, (existing buildings) to make another code rule (new buildings) valid.

I agree. The requirements do not make sense. There is an Article 100 definition of Exposed (as applied to live parts), yet it seems 110.26(A)(1) doesn't follow it.

Example 1: New installation into existing building, 480V equipment on one wall, 3' 10" aisle to front of transformer enclosure (transformer is not considered as needing to be examined while energized, per NEC 110.16, why doesn't Table 110.26(A)(1) condition #2 apply?

Example 2: New installation into old building, 480V equipment on one wall, 3' 10" aisle to rear of energized switchgear, rear panels are not removable while equipment is energized, why doesn't Table 110.26(A)(1) condition #2 apply?

Example 3: Replacement installation into old building, 480V equipment on one wall, 3' 10" aisle to front of energized 15kV switchgear, interlocked doors cannot be open while equipment is energized, why does Table 110.26(A)(1) condition #2 only apply if there are written procedures?

 

[kwired]

I agree. The requirements do not make sense. There is an Article 100 definition of Exposed (as applied to live parts), yet it seems 110.26(A)(1) doesn't follow it.

Example 1: New installation into existing building, 480V equipment on one wall, 3' 10" aisle to front of transformer enclosure (transformer is not considered as needing to be examined while energized, per NEC 110.16, why doesn't Table 110.26(A)(1) condition #2 apply?

Example 2: New installation into old building, 480V equipment on one wall, 3' 10" aisle to rear of energized switchgear, rear panels are not removable while equipment is energized, why doesn't Table 110.26(A)(1) condition #2 apply?

Example 3: Replacement installation into old building, 480V equipment on one wall, 3' 10" aisle to front of energized 15kV switchgear, interlocked doors cannot be open while equipment is energized, why does Table 110.26(A)(1) condition #2 only apply if there are written procedures?

IMO condition 2 does apply to your first two examples.

I do have same question of why on example three though.

 

[Gary11734]

Where is that in the NEC?

What electrician would open TWO switchboards at once? Where did this idea come from?

The question is;

Does the code believe we have to work by the worst case scenario when it comes to working space?

It's clear. If I only work on one of two switchboards that have one cover off, I have one with live parts and one that is considered grounded. Condition two would apply.

What is the problem with this logic? Now, where does the code tell me that we can't trust you as an electrician do to know this difference and force me into condition three even though I know the difference for my good?

 

[kwired]

What electrician would open TWO switchboards at once? Where did this idea come from?

The question is;

Does the code believe we have to work by the worst case scenario when it comes to working space?

It's clear. If I only work on one of two switchboards that have one cover off, I have one with live parts and one that is considered grounded. Condition two would apply.

What is the problem with this logic? Now, where does the code tell me that we can't trust you as an electrician do to know this difference and force me into condition three even though I know the difference for my good?

Code loves to use worst case scenario for many things, and inspectors are even better at assuming worst case scenario when interpreting what code says.

Keep in mind 110.26(A) isn't really all that clear as to what they intend it to apply to in the first place. All it says is "likely to require examination, adjustment, servicing, or maintenance while energized". Most figure this applies to switchboards and panelboards, but is not a lot of consistency to what else it applies to. As worded a junction box with a pair of wires in and a pair out - should be required to comply if it is likely someone may take a voltage reading from within that junction box.

 

[Gary11734]

Code loves to use worst case scenario for many things, and inspectors are even better at assuming worst case scenario when interpreting what code says.

Keep in mind 110.26(A) isn't really all that clear as to what they intend it to apply to in the first place. All it says is "likely to require examination, adjustment, servicing, or maintenance while energized". Most figure this applies to switchboards and panelboards, but is not a lot of consistency to what else it applies to. As worded a junction box with a pair of wires in and a pair out - should be required to comply if it is likely someone may take a voltage reading from within that junction box.

I have been in this trade since 1972, and never thought of this scenario in working space. I guess it never came up.

I had an old PM call me on this. A project he's on and ask me my opinion. He was at 41". The inspector said he needed 42", (condition 2) then, he got a call from the county and it was changed to 48", (condition 3)

Keep it 48" and wider and forget about the code!

Thanks for your help...

 

[infinity]

I have been in this trade since 1972, and never thought of this scenario in working space. I guess it never came up.

I had an old PM call me on this. A project he's on and ask me my opinion. He was at 41". The inspector said he needed 42", (condition 2) then, he got a call from the county and it was changed to 48", (condition 3)

Keep it 48" and wider and forget about the code!

Thanks for your help...

That's a good idea. I'm guessing that it's over 150 volts to ground?

 

[charlie b]

What electrician would open TWO switchboards at once? Where did this idea come from?

I think the intent of the code wording is to acknowledge the possibility that two electricians could work in the same room, one working on one switchboard and the other working on the other switchboard. The additional working space required by Condition 3 will give the two electricians more room so as to avoid bumping into each other.

 

[jim dungar]

I think the intent of the code wording is to acknowledge the possibility that two electricians could work in the same room, one working on one switchboard and the other working on the other switchboard. The additional working space required by Condition 3 will give the two electricians more room so as to avoid bumping into each other.

Another typical situation would be two Motor Control Centers across from each other, which provides the ability to work on individual buckets across from each other at the same time.

 

[Gary11734]

I think the intent of the code wording is to acknowledge the possibility that two electricians could work in the same room, one working on one switchboard and the other working on the other switchboard. The additional working space required by Condition 3 will give the two electricians more room so as to avoid bumping into each other.

Hi Charles,


Yes, I agree, but the code should not leave that up to us. You have to interpret what you think is in their mind, not what the code says, or lack of what they say.


I am in the opinion that this personnel are authorized persons only and know the rules. And, they have determined that 110.26(A)(1)(c) , condition 2 in existing buildings is safe. Now, I have to pretzel in my mind that two electricians could be working on two switchboards back to back at the same time. Yes, it could happen, but that is not how I have been trained to look at the code in rooms where switchboards preside. There 's usually a sign outside, "Authorized Personnel Only." They are supposed to know the rules.


But, you are as correct as I am, IMHO. That is why I asked the question. It should be obvious what the code is, and in this case, I think it could be clearer on intent.


Gary

 

[kwired]

I think the intent of the code wording is to acknowledge the possibility that two electricians could work in the same room, one working on one switchboard and the other working on the other switchboard. The additional working space required by Condition 3 will give the two electricians more room so as to avoid bumping into each other.

Maybe, but they are likely to still bump into one another at 4 feet of clearance if working directly across from one another.

MCC and working on a unit near the floor, you likely on your knees at times and using up more than your half of that 4 feet of clearance, but even when standing most of us don't stand so close to the work that we will stay within our half of the 4 feet of clearance.

For the lower voltages this means you only have 18" for your half of the working space.