2008 110.34.A Over 600V Working Space

[iceworm]

Good morning -
I'm interested in opinions on NEC 2008, 110.34.A, Over 600V, Working Space and Guarding. In particular, I am looking at the change in the 2008 Code from the 2005, and earlier.

2005 (and earlier)
110.34(A) Working Space. Except as elsewhere required or permitted in this Code, the minimum clear working space in the direction of access to live parts of electrical equipment shall not be less than specified in Table 110.34(A). ...

Exception: Working space shall not be required in back of equipment such as dead-front switchboards or control assemblies where there are no renewable or adjustable parts (such as fuses or switches) on the back and where all connections are accessible from locations other than the back. Where rear access is required to work on de-energized parts on the back of enclosed equipment, a minimum space of 750 mm (30 in) horizontally shall be provided.

2008
110.34(A) Working Space. Except as elsewhere required or permitted in this Code, equipment likely to require examination, adjustment, servicing, or maintenance while energized shall have clear working space in the direction of access to live parts of the electrical equipment and shall not be less than specified in Table 110.34(A). ...

Exception: Working space shall not be required in back of equipment such as dead-front switchboards or control assemblies where there are no renewable or adjustable parts (such as fuses or switches) on the back and where all connections are accessible from locations other than the back. Where rear access is required to work on de-energized parts on the back of enclosed equipment, a minimum space of 750 mm (30 in) horizontally shall be provided.

The issue:
The requested task is to install PTs inside an MV switchboard. The access to the only feasible location is a side panel with 30" working space. Access for deadbus verification is in another location (other end side panel) that has the proscribed T110.34.A, condition 2, working space of 5 feet. There is no back access. The switchboard is backed up to the wall. All access for maintenance is through the front or the two side panels.

My information is the original installation was per NEC 2002 and the AHJ, quoting NEC 2002, said 5 feet working space was required for the PTs to be in this location - the existing 30" was not enough. After reviewing NEC 1999, 2002, 2005, 2008, I am inclined to agree the AHj was correct in his interpretation of the NEC 2002 110.34.A and Exception.

But, this code section changed in 2008 (2011 reads the same as 2008).

Question:
Does the current code (2008) now allow this installation? Keep in mind, the PT fuses will never be accessed while the switchboard is energized. The bus will be verified dead before the side cover is removed.

All replies will be graciously appreciated

Iceworm

 

[iceworm]

Bummer - no collective knowledge.

I'm back to work. Be gone for a few weeks.

ice