Tap into a panel

[kwired]

I would think that it would be because there's always the chance that a larger fuse could be installed in the disconnect in some cases, thus "Overfusing" the Tap Conductor.

For example a 125 amp tap to a 125 amp fuse installed in a 200 Amp Rated Disconnect or a 225 Amp tap to a 225 Amp Fuse installed in a 400 Amp Disconnect.

I don't agree either. If you have 125 amp fuse in a 200 amp disconnect, there is a good chance you only have 125 amp conductor on the load side, so if you put in a 200 amp fuse you have protection issues with the load side as well. What is the point of even making 110, 125, 150 and 175 amp fuses if that is the case? Unless you want to make a designated fuse holder that will only accept one size of fuse for each standard rating.

 

[jap]

I don't agree either. If you have 125 amp fuse in a 200 amp disconnect, there is a good chance you only have 125 amp conductor on the load side, so if you put in a 200 amp fuse you have protection issues with the load side as well. What is the point of even making 110, 125, 150 and 175 amp fuses if that is the case? Unless you want to make a designated fuse holder that will only accept one size of fuse for each standard rating.

Because the wording about sizing to the "Rating of the Device" seems to be associated to the Tap rule and not the other applications.

So what is the reason for having to size to the "Rating" instead of the size of the "OCPD"? TYpo ?

 

[Smart $]

Because the wording about sizing to the "Rating of the Device" seems to be associated to the Tap rule and not the other applications.

So what is the reason for having to size to the "Rating" instead of the size of the "OCPD"? TYpo ?

Probably just an error of omission and/or lack of forethought. Could even be the intent was rating of equipment or OCPD, whichever is larger.