I Beam in residential basement

[macmikeman]

Re: I Beam in residential basement

like I said, I came across a gutter downspout that was energized. In this case I found nm stapled outside along the exterior of the facia (in the weather and the sunlight). It was pinched where it was stuffed behind the downspout and turned a corner. All installed by Mr. Homeowner. I doubt Mr. Badger's tool chest would suffer this same fate, but there are plenty of diy's out there who would be glad to try attaching romex along a steel beam in a haphazard manner which could result in a ground fault. My point was it isn't required to bond that beam, but it isn't a bad idea either.

 

[petersonra]

Re: I Beam in residential basement

Q: If one were to run a piece of NM along such a beam, would that be sufficient to make the beam "likely to become energized"?

 

[jim dungar]

Re: I Beam in residential basement

Not in my opinion.

If the NM insulation system is likely to fail and energize this beam, then it is likely to fail inside a wall and burn down the house.

"Likely" means "probable" not "possible". If a word is not specifically defined in Article 100, then the NEC consider it to be defined by common usage, which means go a standard dictionary.

 

[electricmanscott]

Re: I Beam in residential basement

Originally posted by petersonra:
I have always considered the phrase "likely to become energized" as really meaning "it could happen, even if the chance is remote". That seems to be the way it is typically interpreted.

You can't change the meaning of the word to suit your interpretation. Likely to become energized means that in all likely hood it WILL become energized.

 

[electricmanscott]

Re: I Beam in residential basement

Originally posted by electricmanscott:

Originally posted by petersonra:
I have always considered the phrase "likely to become energized" as really meaning "it could happen, even if the chance is remote". That seems to be the way it is typically interpreted.

You can't change the meaning of the word to suit your interpretation. Likely to become energized means that in all likely hood it WILL become energized.

Now if it said "likely to become energized in the event of a fault" it might make a little more sense. Not much but a little bit.

 

[pete m.]

Re: I Beam in residential basement

Could someone enlighten me as to why, in 250.104, water lines are to be bonded without regard to whether or not they are "likely to become energized" when other metal piping and building steel have the provision that states "where likely to become energized".

If there were a section of water line ran across the joists in an unfinished basement that has no electrical wiring around it how would it make the installation any more safe if there were a bond to this isolated section of water line?

The same question could also be asked for the steel I-beam, although the NEC only requires bonding where it is "likely to become energized"

The more I read this book the less I think I truly understand and/or know.........

Pete

 

[jim dungar]

Re: I Beam in residential basement

An isolated piece of water pipe does not need to be bonded unless it is likely to be energized.

For example in a system where the entire water system is CPVC piping:
A metallic stub and faucet from a cartridge style water filter does not need to be bonded.
A metallic stub and faucet from an electric instant (on-demand) water heater does need bonding.

 

[petersonra]

Re: I Beam in residential basement

Originally posted by jim dungar:
An isolated piece of water pipe does not need to be bonded unless it is likely to be energized.

For example in a system where the entire water system is CPVC piping:
A metallic stub and faucet from a cartridge style water filter does not need to be bonded.
A metallic stub and faucet from an electric instant (on-demand) water heater does need bonding.

how do you figure the stub on the water heater is "likely" to become energized? the only time it would become energized is if it faulted, so in effect you are making the judgement that the unit is likely to fail in a specific way.

 

[LarryFine]

Re: I Beam in residential basement

Originally posted by petersonra:

Originally posted by jim dungar:
An isolated piece of water pipe does not need to be bonded unless it is likely to be energized.

For example in a system where the entire water system is CPVC piping:
A metallic stub and faucet from a cartridge style water filter does not need to be bonded.
A metallic stub and faucet from an electric instant (on-demand) water heater does need bonding.

how do you figure the stub on the water heater is "likely" to become energized? the only time it would become energized is if it faulted, so in effect you are making the judgement that the unit is likely to fail in a specific way.

Actually, the stub is most likely to become energized by the water heater itself, and is considered to be grounded by the EGC of the appliance which is likely to be doing the energizing, like the feed to a furnace is.

 

[don_resqcapt19]

Re: I Beam in residential basement

Here is some history on the change from "may" to "likely"

5-197 Log #2484 NEC-P05
(250-104(B))
Final Action: Accept
Submitter: Paul Dobrowsky Holley, NY
Recommendation:
Revise as follows:
(B) Other Metal Piping. Where installed in or attached to a building or structure, metal piping system(s), including gas piping, that is
likely to (may) become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122 using the rating of the circuit that is likely to (may) energize the piping system(s). The equipment grounding conductor for the circuit that is likely to (may) energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.
Substantiation:
The term "may" should "only be used where it recognizes discretionary judgment on the part of an authority having jurisdiction" according to 3.1.2 of the NEC Style Manual. The phrase "likely to become energized" is provided in Annex B of the NEC Style Manual as meaning "failure of insulation on".
Panel Meeting Action: Accept
Number Eligible to Vote: 16
Affirmative: 15 Ballot Results: Negative: 1
Explanation of Negative:
BRENDER: This is a major change in the intent and application of the Code without justification. The intent of present Code language is that all metal water piping should be bonded, for purposes of safety.
This proposal would eliminate that requirement. There is no way an inspector or other person could anticipate future changes to the electric system. Present wording was established to help ensure present and future safety of personnel.
Section 3.2.1 of the Style Manual includes "likely" as possibly being unenforceable and vague. "May" is a much more encompassing
term than "is likely."

5-146 Log #1229 NEC-P05 Final Action: Reject
( 250.104(B) )
________________________________________________________________
Submitter: Donald A. Ganiere Ottawa, IL
Comment on Proposal No: 5-197
Recommendation: Panel should reject this proposal.
Substantiation: The comments of Mr. Brender are correct. This is not a simple word change. The replacement of ?may? with ?is likely to? changes
the meaning of the section. The word ?may? would apply any time that it is physically possible that the piping could become energized. When you change this to ?is likely to? you bring in a much higher standard, and it would be very difficult to insist that all metal water piping be bonded.
Panel Meeting Action: Reject
Panel Statement: The substantiation provided was incorrect and based on the premise that the change affected the bonding requirements on water piping, which is not true. This section only deals with ?other piping systems? that are ?likely to become energized?. The change made is in accordance with the NEC Style manual.
Number Eligible to Vote: 16
Ballot Results: Affirmative: 15 Negative: 1
Explanation of Negative:
BRENDER: This proposal constitutes a major change in the intent of this section. The comment should be accepted. If the word ?may? is unacceptable, perhaps ?is subject to? would be a better term. Use of the word ?likely? introduces a much higher standard to achieve.