Busway (Buss Duct) and NEC 110.26 - Height Clearance

[flemdog186]

Greetings Forum, I have a high-rise building that I am evaluating. In 2007 half the building was renovated and the big electrical distribution was changed from conduit/wire to buss duct. Apparently because it was a renovation and the designers/contractors didn't want to rip out existing utilities, some of the new busway was installed under lots of sprinkler, plumbing, sanitary, telephone, etc. Needless to say, some of the buss duct is now failing. My question is: Was it code compliant to install this 1000 amp, 480 volt, buss duct and not have clearances as described in NEC 2005 110.26.A.3 Height Of Working Space? 110.26 starts off with:II. 600 Volts, Nominal, or Less
110.26.A.3 Height Of Working Space
"Sufficient access and working space shall be provided and maintained about all electric equipment to permit ready and safe operation and maintenance of such equipment. Enclosures housing electrical apparatus that are controlled by a lock(s) shall be considered accessible to qualified persons."
- the buss duct is top access and in many cases there is only a one foot below parallel pipes or ceiling. Any Thoughts?

 

[ron]

You will need to decide if the busway requires examination, adjustment, servicing, or maintenance while energized. (110.26(A))

Is it straight busway sections or are there bus plugs in "violation" too?

 

[jim dungar]

Needless to say, some of the buss duct is now failing.

Something is missing. None of the items you described would necessarily cause bus duct to fail within 6 years of installation.

Except at access points (e.g. joints) feeder duct is not treated substantially different than most conduit runs. However, in recent years, many insurance companies have been asking for bus duct, which are installed in the vicinity of sprinklers, to be drip or splash resistant.

I have seen tremendously more installations of feeder bus duct which were not required to meet 110.26 clearances, than I have those that were.

 

[flemdog186]

Ron, I had to re-read that section but Yes..."while energized" is key and for this building, it does not have to be repaired or maintained while hot. In that case, it appears that the installation may have been compliant. Thanks for the input..

 

[GoldDigger]

Something is missing. None of the items you described would necessarily cause bus duct to fail within 6 years of installation.

Just Murphy's Law which says that it will fail sooner the harder it is to access.
Possibly the failures are coming from incorrect installation and use rather than environmental issues?