10 ft. tap question

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nunu161

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if im tapping off of a set of 500's to feed a 150 amp panel would i be able to use #1's in the 90 degree column to feed the panel since i dont have a breaker directly protecting these conductors?
 
nunu161 said:
if im tapping off of a set of 500's to feed a 150 amp panel would i be able to use #1's in the 90 degree column to feed the panel since i dont have a breaker directly protecting these conductors?
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At the load end (the new panel) they will terminate in an OCPD, what are the lugs rated

for on this OCPD ?
 
You'll need an OCPD within 10' of the tap. #1 THHN is good for 130 amps so the best you can do is a 125 amp OCPD for the panel.
 
nunu,

Without looking it up, I'm pretty sure a tap has to terminate in an OCPD to be NEC

compliant. Also, when I asked for the rating of the panel lugs, 75deg or 90deg, was the

intent.
 
NEC 240.21 (B)(1) says nothing about terminating on an ocpd, the panel is protected by the breaker feeding the 500's, why would the temperature rating of the lugs matter on the main lug panel 150 amps is a 150 amps the maximum wire rating is still equal to the lugs
 
nunu161 said:
NEC 240.21 (B)(1) says nothing about terminating on an ocpd, the panel is protected by the breaker feeding the 500's, why would the temperature rating of the lugs matter on the main lug panel 150 amps is a 150 amps the maximum wire rating is still equal to the lugs
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The tap conductor is rated for 130 amps. What will protect those conductors from overcurrent, the OCPD ahead of the 500 kcmil conductors?
 
The UL listing for panelboard (QEUY) states that panelboard terminations are listed for 60? for wire sizes 14-1 unless otherwise marked.
So it would seem your #1 is limited to 110 amps unless the panelboard is marked otherwise.
 
using a 150 amp panel btw this isn't an installation im just asking is this would be legal to do and if not what says i cant
 
augie47 said:
The UL listing for panelboard (QEUY) states that panelboard terminations are listed for 60? for wire sizes 14-1 unless otherwise marked.
So it would seem your #1 is limited to 110 amps unless the panelboard is marked otherwise.
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Gus,

Now there's a little tidbit I never knew about, Thank You!
 
240.21 says that conductors shall be protected where they recieve theyre supply they are recieving theyre supply off of another wire. Finish reading the article and tell me what the exceptions are because the exceptions look to me like the tap rules but idk maybe my book is a misprint
 
My opinion is that the 10 ft tap rule is one (maybe the only one) that does not specifically state terminate in a single overcurrent device.
It states (a) terminate in a "device" and if you look up "device" in Art 100 it seems to cover panelboards; and (B) the calculated load must not exceed the ampacity.
I don't like it, but from reading, I'd say the Code would allow you to terminate in a MLO panel if your calculated load allowed.
 
augie47 said:
My opinion is that the 10 ft tap rule is one (maybe the only one) that does not specifically state terminate in a single overcurrent device.
It states (a) terminate in a "device" and if you look up "device" in Art 100 it seems to cover panelboards; and (B) the calculated load must not exceed the ampacity.
I don't like it, but from reading, I'd say the Code would allow you to terminate in a MLO panel if your calculated load allowed.
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that was my opinion also. it isn't practical or the safest way i wouldnt make an installation like this unless i came across some crazy retrofit but i found it to be an interesting topic
 
nunu161 said:
240.21 says that conductors shall be protected where they recieve theyre supply they are recieving theyre supply off of another wire. Finish reading the article and tell me what the exceptions are because the exceptions look to me like the tap rules but idk maybe my book is a misprint
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What about the part in 240.21 that says, No conductor supplied under the provisions of

240.21(A) thru (G) shall supply another conductor under those provisions, except through

an Overcurrent Protective Device meeting the requirments of 240.4.
 
agree don't like but agree...
If you have branch OCPs the conductors meet that requirement.
I never "volunteer" that info.... but I can't argue the point if challanged.
 
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