Disconnect requirements for exterior located transformer

[warrenwaldrop]

I am trying to determine whether a disconnecting means is required on the primary of a pad mount transformer, located on the exterior of a building, that is fed from building #1 and feeds a switchboard that is to be installed on the exterior of building #2.

Everything that I read in Article 225 and 230 seems to indicate that I have to have a disconnecting means on the primary side of the transformer at the transformer since the transformer would be considered a structure.

Is there something that I am missing.

 

[M. D.]

I'm no expert but regardless if it is required I would figure it in.,,, it could save a life. Here is an article I found thought it might help
http://ecmweb.com/mag/electric_wiring_building_switchboard/

And this I ,..well,.. it gives me something to be a little more thankful about... as in the past I have acted much like the young man featured here,.. I'm trying to be more thoughtful these days...

http://ecmweb.com/construction/electric_case_locked_switch/

 

[BAHTAH]

Building disconnect

Building disconnect

I am trying to determine whether a disconnecting means is required on the primary of a pad mount transformer, located on the exterior of a building, that is fed from building #1 and feeds a switchboard that is to be installed on the exterior of building #2.

Everything that I read in Article 225 and 230 seems to indicate that I have to have a disconnecting means on the primary side of the transformer at the transformer since the transformer would be considered a structure.

Is there something that I am missing.

IMO the disconnect would be required at building#2. This is the disconnect for the supply to that building, not because the transformere is a "structure" but because building #2 requires a disconnect on the feeder that supplies that building. The disconnect is required to be installed either inside or outside at the closest point of supply, which happens to be the primary side of your transformer. Depending on your type of facility and the AHJ there is an exception to this requirement. 225.31 Disconnecting means and 225.32 Location and 225.32 Exception No. 1.