COMMENT 4-79 225.52

[fmtjfw]

4 Comment:

225.52 Disconnecting Means.
(F) Identification. Where a building or structure has any combination of feeders, branch circuits, or services passing through or supplying it, a permanent plaque or directory shall be installed at each feeder and branch-circuit disconnect location that denotes all other services, feeders, or branch circuits supplying that building or structure or passing through that building or structure and the area served by each. If the building or structure is not required to have disconnects, the permanent plaque or directory as required above shall be installed at each point the circuits passing through enter.

5 Statement of Problem and Substantiation.

Let us start with the purpose of 225.51(F). I believe it is to protect electricians working on circuits in the building or structure and to protect firemen in the case they need to enter the building under emergency conditions.

The most extreme case is a building or structure that has no electrical equipment but has circuits feeding through it.

 

[petersonra]

4 Comment:

225.52 Disconnecting Means.
(F) Identification. Where a building or structure has any combination of feeders, branch circuits, or services passing through or supplying it, a permanent plaque or directory shall be installed at each feeder and branch-circuit disconnect location that denotes all other services, feeders, or branch circuits supplying that building or structure or passing through that building or structure and the area served by each. If the building or structure is not required to have disconnects, the permanent plaque or directory as required above shall be installed at each point the circuits passing through enter.

5 Statement of Problem and Substantiation.

Let us start with the purpose of 225.51(F). I believe it is to protect electricians working on circuits in the building or structure and to protect firemen in the case they need to enter the building under emergency conditions.

The most extreme case is a building or structure that has no electrical equipment but has circuits feeding through it.

I am not sure what the purpose is. Electricians are supposed to be smart enough to protect themselves from the hazards associated with electricity.

Note the word I highlighted in red. It appears the directory requirement only applies to circuits not covered by the disconnecting means at hand.

Why not just have a requirement that says that every structure requires a directory or plaque listing the circuits feeding or passing through the structure that includes the location and identification of the disconnecting means for those circuits?

 

[fmtjfw]

I am not sure what the purpose is. Electricians are supposed to be smart enough to protect themselves from the hazards associated with electricity.

Note the word I highlighted in red. It appears the directory requirement only applies to circuits not covered by the disconnecting means at hand.

Why not just have a requirement that says that every structure requires a directory or plaque listing the circuits feeding or passing through the structure that includes the location and identification of the disconnecting means for those circuits?

Also to protect FIREMEN. The question is where to place plaque. For services and disconnecting means, you place one at each location on of one of these (sort of like cross-references). With the degenerate case of no disconnects just passthroughs, I picked a each entrance.

 

[petersonra]

How does a sign protect anyone?

What if the sign is wrong or they misread it?

I think this is somewhat misguided.

 

[fmtjfw]

How does a sign protect anyone?

What if the sign is wrong or they misread it?

I think this is somewhat misguided.

You could apply the same question and statement to:

230.2 Number of Services.
(E) Identification. Where a building or structure is supplied by more than one service, or any combination of branch circuits, feeders, and services, a permanent plaque or directory shall be installed at each service disconnect location denoting all other services, feeders, and branch circuits supplying that building or structure and the area served by each. See 225.37.