Tap rule

Hello,
My question is:
Is there a tap rule that works like this? This is in regards to 240.21 If I have a 3 phase welder that is fed from a 40 amp disconnect, all 3 legs are fused to 40 Amps. Is it permissible to take 12 ga. taps from the load side of that disconnect and feed another device. The line is less than 10 feet and is fused at the device to 10 amps.
Thank you!
 
Thank you

Thank you

240.21 is about feeder taps, the welder circuit is a branch circuit.

So in my opinion no.
Thank you for your response! Is there then any Tap rule that will allow coming off of the load side of a disconnect with wire that is less than the rated fuses of that disconnect? Whether it is 10' or less.. and if the device being fed is fused less than the tapped amp rating of the feed wire?
 
Thank you

Thank you

Thank you for your response!

So I ask then, is there any tap rule that allows taking a smaller conductor than what the fuses are rated at in a disconnect. Whether it is 10' or less? And if the line is fused for less than the rated ampacity of the wire feeding another device from that said disconnect?
 

augie47

Moderator
Staff member
Location
Tennessee
240.21 is about feeder taps, the welder circuit is a branch circuit.

So in my opinion no.
devil's advocate here... if the second device is protected by a set of fuses would the circuit not then also be a feeder ?
Can it be both ?
 

Smart $

Esteemed Member
Location
Ohio
It depends on whether the tap load is one permitted under 210.19(A)(4) Exception No. 1.

Exception No. 1: Tap conductors shall have an ampacity
suffıcient for the load served. In addition, they shall have
an ampacity of not less than 15 for circuits rated less
than 40 amperes and not less than 20 for circuits rated
at 40 or 50 amperes and only where these tap conductors
supply any of the following loads:
(a) Individual lampholders or luminaires with taps extending
not longer than 450 mm (18 in.) beyond any portion
of the lampholder or luminaire.
(b) A luminaire having tap conductors as provided in
410.117.
(c) Individual outlets, other than receptacle outlets,
with taps not over 450 mm (18 in.) long.
(d) Infrared lamp industrial heating appliances.
(e) Nonheating leads of deicing and snow-melting
cables and mats.
 

Smart $

Esteemed Member
Location
Ohio
devil's advocate here... if the second device is protected by a set of fuses would the circuit not then also be a feeder ?
Can it be both ?
Code does not specifically say a circuit cannot be both. Judging by the context of the entire Code, I lean towards no, now... but I leaned the other way for a long time.
 
Smart

Smart

Thank you Smart,

I can only find myself that this is permissible for luminaries and not other load devices? I am being told by a licensed Electrician that this is permissible, but I am in disagreement with him..
That is why I am asking?
 

Smart $

Esteemed Member
Location
Ohio
Thank you Smart,

I can only find myself that this is permissible for luminaries and not other load devices? I am being told by a licensed Electrician that this is permissible, but I am in disagreement with him..
That is why I am asking?
What load are you wanting [or not wanting] to connect?

210.19(A)(4) Exception No. 1 item (c) is open to interpretation.
 

kwired

Electron manager
Location
NE Nebraska
Thank you for your response!

So I ask then, is there any tap rule that allows taking a smaller conductor than what the fuses are rated at in a disconnect. Whether it is 10' or less? And if the line is fused for less than the rated ampacity of the wire feeding another device from that said disconnect?
Whether or not a circuit can be both a feeder and a branch circuit at the same time has been brought up here a few times before. I can't recall ever having a general consensus of an answer either.

IMO the 240.21 tap rules would be the rules that set the limits on overcurrent protection and length of tap conducors, but I guess it really comes down to can you make such a tap to what is already a branch circuit, and I don't think there is a direct yes or no answer in the NEC.
 
Ambiguous answer

Ambiguous answer

Whether or not a circuit can be both a feeder and a branch circuit at the same time has been brought up here a few times before. I can't recall ever having a general consensus of an answer either.

IMO the 240.21 tap rules would be the rules that set the limits on overcurrent protection and length of tap conducors, but I guess it really comes down to can you make such a tap to what is already a branch circuit, and I don't think there is a direct yes or no answer in the NEC.
I was really hoping to find something more concrete than it being not answerable? Surely someone has run into this and has either been accepted or denied. Or is it up to the visiting inspector? And his or her interpretation?
 

kwired

Electron manager
Location
NE Nebraska
I was really hoping to find something more concrete than it being not answerable? Surely someone has run into this and has either been accepted or denied. Or is it up to the visiting inspector? And his or her interpretation?
I recall past discussions on whether one could tap a household range circuit and feed say a range hood if you provided proper overcurrent protection of the tapped portion of the circuit, and no general consensus of whether it was allowed. The discussion did come up that the circuit can't be both a feeder and a branch circuit. The reality is there is likely no significant life or property hazard introduced by doing such an installation, yet there is nothing in NEC that specifically allows or prohibits it either.
 

augie47

Moderator
Staff member
Location
Tennessee
Everything is up to the Authority Having Jurisdiction :)
If your conductors terminate at an overcurrent device, I'd lean toward accepting it but I have found Iwires opinions to be very sound so I may be overlooking something.
 

Smart $

Esteemed Member
Location
Ohio
The device would be a PLC that runs the robot for said Welder
IMO that would be permitted under the exception item (c) as long as you hardwire it (ie. no receptacle). Your tap conductors cannot be any longer than 18", which means your "supplementary overcurrent protection device" must installed within that distance if you want to go further.

However, as stated by Gus (augie47), it's subject to the AHJ's interpretation.
 

kwired

Electron manager
Location
NE Nebraska
240.21 is about feeder taps, the welder circuit is a branch circuit.

So in my opinion no.
240.21(B) is about feeder taps, 240.21(A) is branch circuit taps - but doesn't give you much information and instead just sends you to 210.19 and 20, and all that is mentioned there that has anything to do with a possible tap conductor is related to luminaires, cooking equipment, industrial heating appliances, or what could possibly apply to the OP is "Individual outlets, other than receptacle outlets, with taps not over 450 mm (18 in.) long". This would be 210.19(A)(4)(c) that possibly could apply.
 
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