Bus Duct Clearances

[trickrider16]

Enigneer stated we need to provide working clearances for our joints in our bus duct, for infraded testing. Any ideas on this? I believe that is an enclosed raceway per article 100 but I don't want to leave it up to judgment.

 

[ron]

He interprets it to require service while energized. Sounds like a good idea.

 

[trickrider16]

Yeah but the installion didn't really permit for clearances at every joint.

 

[ron]

Was it not practical (didn't really) or not convenient?

If the specfications are part of your contract, you are bound by their instructions for payment.

Does the manufacturers instructions for the bus require clearance?

If it wasn't practical, then send a request for information to the Engineer for clarification or instruction.

 

[ron]

For example, I was just looking at the Square D Busway installation instructions and it indicates:

"Provide sufficient horizontal and vertical clearance from walls and ceilings to provide easy access to joints"

Because it is in the manufacturers instructions, it is likely listed that way and it is required for UL listing compliance.

 

[infinity]

IMO it is not a raceway. Clearance must be provided at the joints for maintenance but the question how much is required. According to Article 368 if the busway is exposed it's only required to be in the open where visible.

 

[charlie b]

. . . Square D Busway installation instructions . . . indicates: "Provide sufficient horizontal and vertical clearance from walls and ceilings to provide easy access to joints"

That is not the same thing as saying it requires "working clearance," per 110.26.

 

[infinity]

That is not the same thing as saying it requires "working clearance," per 110.26.

I was think that too. And how does one define "easy access"? If I'm 5'6" 130#'s a 1 foot space would provide easy access. If I'm 6'5" 350#'s the 12" won't help much. :blink:

 

[ron]

That is not the same thing as saying it requires "working clearance," per 110.26.

I agree, although "easy access" sounds somewhat nebulous and unenforceable.

 

[trickrider16]

Awesome, that easy access makes more sense. It looks like I need to revisit our submittals or go straight to the manufacturer. Thanks

 

[jim dungar]

I agree, although "easy access" sounds somewhat nebulous and unenforceable.

Square D isn't giving a code requirement, they are simply letting you know what is needed for installation. I have seen many busduct installations that are within 6 inches of a wall. Their bus has about a dozen screws on each joint's side panels. Joint maintenance is from the top or the bottom.