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Posted By: watersparkfalls 240 tap rules - 11/26/09 04:12 AM
I have a question about taps not over 25 foot.

Scenario:
I have a 320 amp service w/twin meter outside a well house with 2-200 amp Main breakers(established service). One breaker feeds the shop and the other feeds the house and the well house. Here in the meter base on the customer side I used tap blocks to w/4/O AL to feed 200 amp panel in house and 1/O AL to feed 100 amp panel(12 feet from meter base) in the well house and 4/O from main breaker to a 3 hole tap block in meter base. Originally I came from back of meter base with 1/O SER cable and fed 100 amp panel inside well house(not in a raceway)this cable was inside the wall of well house and above in trusses, which is going to be finished with drywall. Is physical damage applied to cables in a wall? I read the not over 25 foot rule as not specifically requiring a raceway as written in 10 foot rule or over 25 foot rule. Am I reading to deep into other approved means? To pass my inspection I changed SER cable to underground direct burial wire and ran outside the well house to panel, using the outside tap rules.
Thanks Guys and Happy Turkey Day!!!
H2O
Posted By: KJay Re: 240 tap rules - 11/29/09 05:12 AM
Not sure I'm following the question completely, but 240.21,[2] in the '08 NEC states as a requirement that "The tap conductors are protected from physical damage by being enclosed in an approved raceway or by other approved means".
This is also mentioned as one of the requirements in 240.21,[4] Taps Over 25 Feet Long.

IMO, I think an approved raceway is easy enough to comply with, but as far as what "other approved means" would be... that sounds like it is going to be up to the actual AHJ to decide.
Posted By: renosteinke Re: 240 tap rules - 11/29/09 03:45 PM
I think you have to read between the lines a bit.

For example ... bus duct. Is it enclosed? Is it a receway? Or, perhaps, is it a specialty product, designed specifically for this use?
Posted By: KJay Re: 240 tap rules - 11/30/09 01:05 AM
IMO, I'd say that busway is both a raceway, as defined in Art.100, as well as an enclosure as described in 368, but I think the question remains... is it approved for this installation, since it cannot be used where exposed to "severe physical damage", a term which also appears to not be clearly defined. Another question to the AHJ?
Posted By: renosteinke Re: 240 tap rules - 11/30/09 02:04 AM
It's simply not possible to write any set of rules that covers each and every possible situation over an endless period of time - if for no other reason than the limits of language.

That's why the "master's" get the respect, and why the AHJ is not some committee meeting in a hotel room someplace.

Forget the techno-babble. All anyone can do is be prepared to persuade twelve of their neighbors that they made the right call.
Posted By: KJay Re: 240 tap rules - 11/30/09 03:20 AM
I suppose Reno, but I think in the OP's case, the first step should be to at least pass inspection before he moves on to a trial by jury. smile From what I can gather, it sounds like maybe he’s already had to rework the installation once already.

I’m also assuming that his inspector most likely has access to information available from the AHJ to assist with his interpretations as to what is acceptable, but don’t know for sure, so maybe not.
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