NFPA 70 + NFPA 13 conflict

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mpd said:
even if you bond the sprinkler piping, do the sprinkler fittings effectively bond the sections of pipe?
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What would be likely to energize it??? even if it is isolated
 
M. D. said:
What would be likely to energize it??? even if it is isolated
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any faulty wiring that is hanging in a ceiling area (the same kind of sources that energize ceiling grids, bldg steel, electricians on ladders, etc)
 
M.D.

my point is that if the sprinkler fittings isolate each section of pipe, what good would bonding one section of pipe do? can you effectively bond sprinkler piping?
 
DanZ said:
http://www.mikeholt.com/newsletters.php?action=display&letterID=191http://www.mikeholt.com/newsletters.php?action=display&letterID=191
http://www.mikeholt.com/newsletters.php?action=display&letterID=26
http://www.mikeholt.com/mojonewsarchive/All-HTML/HTML/Grounding-vs-Bonding-Online-Training-5~20050715.php
http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Grounding-versus-Bonding-Part-2-of-12~20041014.php
Does any of this help?
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None of those address the sprinkler situation. . They all good general information but I doubt I'll get enough of the fire marshalls attention to get him squared away on all things grounding. . Even MD posted link only talks about bonding the sprinkler to a lightning system, if existing.

http://forums.mikeholt.com/showthread.php?t=79103

Nothing I've read yet addresses the subject directly.

I don't agree with some here that have stated their belief that the sprinkler is "other metal piping" under 250.104(B), so the "likely to become energized" wording doesn't matter to me.

I see the sprinkler as "metal water piping" under 250.104(A). . But I see the point of others that have said that the sprinkler strut straps and hangers are directly attached to the structural steel and so already bonded thru that connection and no further conductors are required.

I think that I'm going to drop the issue and file it away as another lesson learned. . I had never heard of the sprinkler electrode prohibition in NFPA 13 before. . Now I know and next time won't be surprised if it comes up.
 
David you might want to talk to Ryan Jackson

http://www.iccsafe.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=11;t=000915

RyanJackson said:
Alright. I just got off the phone with the UL rep from panel 5, and we talked about my proposal. The proposal was rejected, but thats OK, because I knew it would...I was just hoping for a panel statement to answer the issue.

Anyway, according to panel 5, if the sprinkler piping is a metal system it is a 250.104(A) (water) installation. If it is broken up with nonconductive couplings, it is a 250.104(B) (other) installation.

--------------------
Ryan Jackson
Salt Lake City
Inspector, Instructor,
Code Consultant
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here is his proposal



5-240 Log #1448 NEC-P05

Final Action: Reject​



(250.104(B))​


____________________________________________________________

Submitter: ​

Ryan Jackson, West Valley City, UT
​




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 and fire sprinkler piping
, that is likely to 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
uses. The bonding jumper(s) shall be sized in accordance with 250.122 using
the rating of the circuit that is likely to energize the piping system(s). The
equipment grounding conductor for the circuit that is likely to 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: ​

There is a long-standing debate as to whether fire sprinkler
​



piping is a 250.104(A) or 250.104(B) type of piping. I have spoken with

several code experts on this issue, including multiple members of Panel 5, and
have received different answers on this issue. Accepting this proposal would
end this debate, and would be a step forward in the uniform interpretation of
this rule, which is something that we should all be striving for.​

Panel Meeting Action: Reject
Panel Statement: ​

A metallic fire sprinkler piping system is metal water piping
​



system that is covered by Section 250.104(A). Section 250.104(A) does not

differentiate or exclude between the various types of metal water piping
systems that might be present in a building or structure. Section 250.104(B)
covers metal piping systems other than those metal water piping systems
covered by 250.104(A).​

Number Eligible to Vote: 15
Ballot Results: ​

Affirmative: 15

​
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​
 
This is what the fire marshall makes his ruling on.

2002 NFPA13 (Sprinkler Systems)
10.6.7* When it is necessary to join metal pipe with pipe of dissimilar metal, the joint shall be insulated against the passage of an electric current using an approved method.
10.6.8 In no case shall pipe specified in 10.6.7 be used for grounding of electrical services.
(Annex-Explainatory material)
A.10.6.7 Gray cast iron is not considered galvanically dissimilar to ductile iron. Rubber gasket joints (unrestrained push-on or mechanical joints) are not considered connected electrically. Metal thickness should not be considered a protection against corrosive environments. In the case of cast-iron or ductile iron pipe for soil evaluation and external protection systems, see Appendix A of AWWA C105, Polyethylene Encasement for Ductile Iron Pipe Systems.
 
So we don't need a bonding jumper based on the service size, like the water piping does, but only sized for the circuit likely to energize the piping, if there even is one.

So, what circuit is likely to energize a sprinkler system? Who determines whether there is such a circuit in any given installation, say with no fire pump or alarm circuit?

There very well may be no such circuit, meaning that bonding sprinkler piping is clearly not a universal requirement.
 
LarryFine said:
So we don't need a bonding jumper based on the service size, like the water piping does, but only sized for the circuit likely to energize the piping, if there even is one.
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If it has nonconductive couplings, then you go to 250.104(B) and the "likely to energize" wording.

LarryFine said:
So, what circuit is likely to energize a sprinkler system? Who determines whether there is such a circuit in any given installation, say with no fire pump or alarm circuit?

There very well may be no such circuit, meaning that bonding sprinkler piping is clearly not a universal requirement.
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There's no clear way to determine if such a circuit is present and which circuit is the "likely" one. . We always handle 250.104(B) the same way. . Ignore your service disconnect size, pick the largest OCPD in the building [feeder or branch circuit] and size according to that.
 
dnem said:
... But that throws me right into an electrode vs general bonding conversation with a fire marshall. . I honestly doubt he understands the difference and I don't know if he's open to learn anything from an electrical inspector.
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Tell him it's like shirts and pants, there both clothes but they have differant purposes. :)
 
dnem said:
If it has nonconductive couplings, then you go to 250.104(B) and the "likely to energize" wording.
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I would say if tape or "pipe dope" is employed you move directly 250.104(B)



dnem said:
There's no clear way to determine if such a circuit is present and which circuit is the "likely" one. . We always handle 250.104(B) the same way. . Ignore your service disconnect size, pick the largest OCPD in the building [feeder or branch circuit] and size according to that.
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That is very conservative to say the least,.. do air lines ,.gas pipes , air ducts ,.. waste pipes ,..get treated the same??
 
So your office does not agree with this depiction

250-152web.jpg



Other metal piping systems such as gas or air that are likely to become energized must be bonded to an effective ground-fault current path. The equipment grounding (bonding) conductor for the circuit that may energize the piping can serve as the bonding means. (See NFPA 54, National Fuel Gas Code) Because the equipment grounding (bonding) conductor for the circuit that may energize the piping can serve as the bonding means, no action is required by the electrical installer.
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If you can't determine what that circuit is ,.. then it is not likely to be energized ,..IMO
 
M. D. said:
Because the equipment grounding (bonding) conductor for the circuit that may energize the piping can serve as the bonding means, no action is required by the electrical installer.
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It should say "... no additional action is required ..." :smile:

If you can't determine what that circuit is ,.. then it is not likely to be energized ,..IMO
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In mine, too.
 
M. D. said:
That is very conservative to say the least,.. do air lines ,.gas pipes , air ducts ,.. waste pipes ,..get treated the same??
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"..... air ducts ....."
No, it's a duct not a pipe
"air lines ,.gas pipes , ..... waste pipes"
Yes, get treated the same
But remember that 250.104(B) has the sentence, "The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means." . So if that particular piping system has motors attached, it is those motors that are most likely to energize the pipes and the system is already bonded thru the equipment grounding conductor. . No additional bonding needed.
 
M. D. said:
So your office does not agree with this depiction

250-152web.jpg
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The hot water tank in that picture does not appear to have a blower motor so 250.104(B) would require an additional bond for the hot water pipes. . Since the cold is already bonded to the service [assumed], a hot to cold jumper is all that is needed. . We would tell the contractor to size it according to 250.122 and according to their largest amp breaker, service main excluded.

If the hot water tank did have a motor of some type, then the equipment ground of the motor provides the bond and has already been sized for the motor circuit that it feeds. . So it with usually be allowed to be smaller than a motorless pipe system bonding jumper.

In the real world, the largest breaker in most panels [excluding the main(s)] is usually 300a or less. . 250.122 for 300a is only #4 which is common everyday stuff and also fits in your standard size pipe bonding clamp.
 
dnem said:
The hot water tank in that picture does not appear to have a blower motor so 250.104(B) would require an additional bond for the hot water pipes.
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Why? What is likely to energize the water heater or hot-water piping?
 
dave you answered your own question..if the sprinkler pipe is likely to become energized the item that energizes it can be the bond..so if the switch is grounded then it can serve..If there is no electrical item to energize it then it does not need bonding..
 
LarryFine said:
Why? What is likely to energize the water heater or hot-water piping?
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Wow ! You're right ! . That was a MAJOR brain fart on my part !

Everything I said applies to 250.104(B) not (A)(1).

(A)(1) is water pipe systems and have to be bonded with no "likely to become energized" wording.

(B) is nonwater pipes [or water pipes that don't form a metal system such as nonconductive fitting sprinklers]. . It's the (B) nonwater, such as the natural gas line, that can be bonded thru the equipment ground of the hotwater tank blower motor or the furnace motor.

Sorry for the confusion !
The following applies to the natural gas line NOT the hot water line.

dnem said:
The hot water tank in that picture does not appear to have a blower motor so 250.104(B) would require an additional bond for the hot water pipes. . Since the cold is already bonded to the service [assumed], a hot to cold jumper is all that is needed. . We would tell the contractor to size it according to 250.122 and according to their largest amp breaker, service main excluded.

If the hot water tank did have a motor of some type, then the equipment ground of the motor provides the bond and has already been sized for the motor circuit that it feeds. . So it with usually be allowed to be smaller than a motorless pipe system bonding jumper.

In the real world, the largest breaker in most panels [excluding the main(s)] is usually 300a or less. . 250.122 for 300a is only #4 which is common everyday stuff and also fits in your standard size pipe bonding clamp.
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