Bulldog Pushmatic panel main bus bar terminals

[gbeaumont]

Originally Posted by pabernathy

Is it likely to cause a fire......I dont think so.

hi Mate

that was part of my rationale, I couldn't see any obvious dangers to either personel or equipment, normaly when we see these odd looking taps they leave down stream panels energized even when the main is thrown, that isn't the case here.

So long as the feeder IS of the correct gauge for 30amp, thats the bit that would concern me.

It's an interesting issue.

Regards

Gerry

[Paul W. Abernathy]

Yep....see this is what forums are for....bringing out issues.

When we see a feed-thru panel, traditionally this panels additional lugs are designed to actually extend the panel to another panel and not really for applications of the "Tap" rules the way the code is written right now. Many will TWIST the code to say the bussbar is a conductor, the lugs are a conductor and then try to bring in "websters dictionary" logic into the term of conductor. The fact is the NFPA to the BEST of my knowledge consider a conductor as what it is...a conductor. IN some areas of the code we have busway applications that are being considered as conductors and they define that in their own article and sections as such and are specific to their application but unless we change the wording of the definitions of "feeders" and "feeder taps" we are bound by their application.

The principle concept of protection is that all conductors shall be protected at their ampacity ( nope, thats no cut and paste..I wrote that...) and so we so need the applications of 240.21 (A-H) in order to actually apply taps so it's a good thing but probably way to deep for HI's to venture into, heck it is starting to seem way to deep for ME to venture into. I am always learning and as I said I fall into the camp that believes the tap rules should apply to the lugs since the busbar is in my mind a conductor of sorts and it is on the load side of the disconnection means so if the tap rule mathmatics apply I don't really loose sleep over it but as we see some engineers disagree and say taps must tap feeders to be feeder taps and thus feeder tap rules can only apply to feeders. How was that for a toungue twister.

Here is exactly what the NEC says and you be the judge:

Tap Conductors.

As used in this article, a tap conductor is

defined as a conductor, other than a service conductor, that

has overcurrent protection ahead of its point of supply that

exceeds the value permitted for similar conductors that are
protected as described elsewhere in 240.4.

Feeder.

All circuit conductors between the service equipment,
the source of a separately derived system, or other

power supply source and the final branch-circuit overcurrent

device.

The I posted earlier what an "informal" Senior Electrical Engineer stated in regards to defining feeders and feeder taps....so you be the judge. What I can tell you is that many, many and many electricians and engineers differ on this one and if someone tells you that you are wrong or right.....I can point you to many well known guys who disagree on this issue.

This is a GREAT subject and has spawned a few proposals of my own for the next code cycle.

Here is what the NEC gives us -

Conductor, Bare. A conductor having no covering or electrical
insulation whatsoever.

Conductor, Covered. A conductor encased within material

of composition or thickness that is not recognized by this
Code as electrical insulation.

Conductor, Insulated. A conductor encased within material

of composition and thickness that is recognized by this
Code as electrical insulation.

BUT it never actually tells us what a conductor IS in itself. Can it be a bussbar in a panelboard?. Does it mean lugs are conductors?

You tell me what YOU think it means..........

Here is what websters says about it....( Yes, I Cut and Pasted this from Websters Online to KEEP people happy )

Main Entry: con·duc·tor Pronunciation: \kən-ˈdək-tər\ Function: nounDate: 15th century: one that conducts: as a: guide b: a collector of fares in a public conveyance c: the leader of a musical ensemble d (1): a material or object that permits an electric current to flow easily — compare insulator, semiconductor (2): a material capable of transmitting another form of energy (as heat or sound)

So since the NEC style manual says websters can be used.....and since the NEC uses the term alot I would think it would define it within it's own scope and maybe propose this new definition to the NEC.

Conductor.Bare,Covered or Insulated-a material or object that permits an electric current to flow easily as it applies to the application of an electrical installation.


What do ya think.......should I submit it or do ya think it is needed?

[Jeffrey R. Pope]

UNCLE - I give!

Do you have anything stronger than Advil Gerry?

[Paul W. Abernathy]

Ask him if he has any Diprivan, an anesthetic widely used in operating rooms to induce unconsciousness and I hear it is quite powerful. But it is only advised to be used in the presence of a famous doctor.

[gbeaumont]

Originally Posted by jpope

UNCLE - I give!

Do you have anything stronger than Advil Gerry?

I switched to Scotch hours ago Jeff

Hic

Gerry