Tap Question

[Alwayslearningelec]

I have this existing feeder being extended to new panels. There is an existing tap box.
Does this tap have to be within a certain distance of the panel its feeding per code?
Thanks.

 

[infinity]

The new conductors are the same size (350) so there is no tap.

 

[Alwayslearningelec]

The new conductors are the same size (350) so there is no tap.

Aaahhhh thank you

 

[Alwayslearningelec]

The new conductors are the same size (350) so there is no tap.

But there was a tap there before being demolished(see pic).So is there a distance limitation for that tap box from the panel it's feeding?

 

[Johnhall30]

There is no limitation if there is no tap

 

[augie47]

Look at the definition of a tap (240..2)
In the "existing" you had conductors with an ampacity less than the feeder.
In the new you are just extending the same size feeder (same ampacity)

 

[Alwayslearningelec]

Look at the definition of a tap (240..2)
In the "existing" you had conductors with an ampacity less than the feeder.
In the new you are just extending the same size feeder (same ampacity)

The existing has #2/0 being "tapped" off #350 riser. Is that a tap?

 

[jap]

The existing has #2/0 being "tapped" off #350 riser. Is that a tap?

That would all depend on what size OCPD is upstream of the 350 mcm.

JAP>

 

[infinity]

The existing has #2/0 being "tapped" off #350 riser. Is that a tap?

According to you drawing that is being removed and replaced by the 350s. Now you simply have a splice and no more tap.

 

[Alwayslearningelec]

According to you drawing that is being removed and replaced by the 350s. Now you simply have a splice and no more tap.

I completely understand that . Here is my point . I’m trying to determine the location of the existing tap box as it affects my new conduit feeder extension footage to the new location of panels. Soooooo if the existing is considered a tap would the tap box have to be within a certain distance of the panel it’s feeding ?? If so then I know about where the tap box is and I can scale my footage from there to the new panels .

 

[infinity]

I completely understand that . Here is my point . I’m trying to determine the location of the existing tap box as it affects my new conduit feeder extension footage to the new location of panels. Soooooo if the existing is considered a tap would the tap box have to be within a certain distance of the panel it’s feeding ?? If so then I know about where the tap box is and I can scale my footage from there to the new panels .

If the tap conductors are 1/3 or larger than the ampacity of the feeder then the tap conductor is limited to 25' in length.

 

[Alwayslearningelec]

Ok so 1/3 larger than the #350? Wtf. How do you determine 1/3 of #350 as it relates to wire size ? OD?

 

[jap]

Ok so 1/3 larger than the #350? Wtf. How do you determine 1/3 of #350 as it relates to wire size ? OD?

Ampacity, not physical size.

JAP>

 

[Alwayslearningelec]

If the tap conductors are 1/3 or larger than the ampacity of the feeder then the tap conductor is limited to 25' in length.

So the 2/0 conductors are larger so the box SHOULD be within 25' of panel....regarding existing setup. Question answered. BTW what code section is this in about 1/3 or larger?

 

[jap]

The ampacity of the Tap Conductor must be 1/3rd the ampacity of the feeder conductor to utilize the 25' tap rule.

Look up the ampacity of 2/0 and see if it's 1/3rd the ampacity of 350mcm.

JAP>

 

[augie47]

I hate to confuse the already confused but technically I believe it's 1/3 of the ampacity of the overcurrent device protecting the feeder being tapped (likely the same as the feeder conductor ampacity but not necessarily)
Beau, This is in 240.21

 

[jap]

That's correct.

JAP>

 

[infinity]

I hate to confuse the already confused but technically I believe it's 1/3 of the ampacity of the overcurrent device protecting the feeder being tapped (likely the same as the feeder conductor ampacity but not necessarily)
Beau, This is in 240.21

That's correct. The feeder ampacity would be determined by the OCPD not the conductor size as I think I mentioned in post 11.

 

[jap]

I mentioned it also in post #8 then worded it wrong in post #15.

Thank goodness for Augie,,,


JAP>

 

[Strathead]

One thing many people overlook is that it is the length of the conductors, not the conduit or lug to lug distance. Bottom line is, you should really read 240.21. There are 5 conditions for the 10 foot tap rule that all must be complied with. 3 for the 25 foot tap rule.