240.21 (B) 10ft tap rule

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AKsparky1

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I have 100A breaker feeding a house panel in a residence. This is the main for the house panel and this enclosure is located outside. I want to tap off the load side of this breaker with #6awg less then 10ft over to a MLO sub panel with two 20A breakers. My question is do the #6awg tap conductors need to terminate in a single OCPD prior to the two 20A breakers with the 10ft tap rule? I see that there was a change in the 2014 NEC "device (s)" in 240.21 B1b.
 
Forget the MLO panel and go with a 60 main breaker

Yes the taps have to terminate in a single breaker or set of fuses.
 
If I read correctly, your plan involves "tapping of the 100 amp breaker". If so keep in mind, it is doubtful the breaker lugs are rated for the two conductors. You may need to use a "polaris" type connector.
 
AKsparky1 said:
The tap will be done with polaris plugs and it is on the load side of the main breaker ahead of the house panel and are service entrance conductors.
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I'm a little confused, if they're on the LINE side of the service disconnect then they're SEC's if they're one the LOAD side then they are not.
 
AKsparky1 said:
on the load side of the main breaker ahead of the house panel. Is this tap required to terminate in a single ocpd or will the two 20A breakers be ok. The sub panel mounted right next to the main disconnect is mlo.
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I believe Iwire answered your question in post 2-- you need to terminate the tap onto an overcurrent protective device.
 
Dennis Alwon said:
I believe Iwire answered your question in post 2-- you need to terminate the tap onto an overcurrent protective device.
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But in another thread it was pointed out that in at least some code cycles the 25 foot tap rule specifies a single OCPD, while the 10 foot tap rule does not. It would seem to allow two or more OCPDs instead of just one.

That is the specific 2014 code wording the OP is referring to.

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GoldDigger said:
But in another thread it was pointed out that in at least some code cycles the 25 foot tap rule specifies a single OCPD, while the 10 foot tap rule does not. It would seem to allow two or more OCPDs instead of just one.

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My point exactly. The 2014 nec made the word 'device' plural by adding an S and it does not say 'single' like the other rules.
 
AKsparky1 said:
My point exactly. The 2014 nec made the word 'device' plural by adding an S and it does not say 'single' like the other rules.
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I am not sure about the the (s), I do not have time now to look up the panel comments but I suspect it has to do with the fact the rule applies to group of fuses as well as a single circuit breaker.

In other words if the tap ends in a single fused disconnect there are three OCPDs involved
 
IMO, that section is talking about a feeder that is tapped to a piece of equipment such as a furnace that may have more than one overcurrent protective device. I don't believe the intent was for a panelboard. I may be wrong but that is how I see it
 
If supplying only a 2 space panel (one overcurrent device per ungrounded line) I don't see any problem with what is being proposed, before or after the mentioned change in 2014. I can see where some may think you need to put a two pole breaker in there though.
 
Dennis Alwon said:
IMO, that section is talking about a feeder that is tapped to a piece of equipment such as a furnace that may have more than one overcurrent protective device. I don't believe the intent was for a panelboard. I may be wrong but that is how I see it
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A feeder tap to a panel is very common.

Think of a taller multi-unit apartment building, it is common to run a large 3 phase riser up through a number of apartment panels each taping off single phase at each panel.
 
iwire said:
A feeder tap to a panel is very common.

Think of a taller multi-unit apartment building, it is common to run a large 3 phase riser up through a number of apartment panels each taping off single phase at each panel.
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But each tap ends in a single overcurrent device (the main breaker) in each apartment panel. Landing in a main lugs panel with lesser bus rating then the feeder would be a violation.
 
AKsparky1 said:
on the load side of the main breaker ahead of the house panel. Is this tap required to terminate in a single ocpd or will the two 20A breakers be ok. The sub panel mounted right next to the main disconnect is mlo.
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Is it that big of a deal to backfeed a 2 pole 60 with a retainer kit and be done with it? What is that, around $10 in parts?
 
Cow said:
Is it that big of a deal to backfeed a 2 pole 60 with a retainer kit and be done with it? What is that, around $10 in parts?
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Makes sense if supplying say a 20 circuit panelboard with it, but he is supplying a 2 pole panelboard with presumably one ungrounded conductor to each pole. Or must you use a breaker with lugs on both ends in this situation? I bet the panel in question is suitable for use as service equipment (some only rated 30 amps may not be, most others are) and if you can land a service conductor on there why not a feeder tap?
 
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