Grounding To a Fire Sprinkler Main Riser

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Greengiant1964

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I was looking in the code seeing if its permitted to have a grounding connection directly to a fire riser on a commercial building.
The fire riser under the ground is plastic and then runs up to metal on the vertical.
The existing ground looks to be #4 or larger ground. It appears that the ground is for IT room.
Just needed some clarification, I was performing a fire inspection and noticed this.
Thanks
 
Without code ref's provided, you might be required to bond the fire sprinklers, but it should never be used as part of the grounding system. Some places won't let you attach anything to the sprinkler pipes. It's certainly the wrong place to attach an "IT" ground.
 
I agree with Zbang. 250.104(A)(1) requires the bonding of metal water piping to the electrical system. The NEC does not disallow its use as an electrode, but I think other NFPA standards may. It is not likely allowable as a grounding electrode for the purpose of IT grounds, unless meeting the exception of 250.52(A)(1), and certainly not suggested for that use.

Various inspectors and departments will forbid the intentional bonding of the pipe, and the fire marshal trumps everyone. :)
 
we just had a similar situation and we were required by the state fire marshall to remove all bonds to sprinkler risers in a complex....sounded like shooting yourself in the foot to me personally....but like the last post...fire marshall trumps all
 
Section 10.6.8 of the NFPA 13 clearly indicates underground portions of the fire sprinkler system must be not be used to ground the electrical system. However, there is no language that would prevent the required bonding in accordance with Section 250.104 of the NEC or Section 4.14 of the NFPA 780 for lightning protection systems. In fact, a new section in the NFPA 13, 10.6.8.1 clearly indicates that nothing in the NFPA 13 is to prevent the required bonding of metal water piping systems above or below ground.
 
I think you can find a better explanation in NFPA 24 Standard for Installation of Private Fire Service Mains and their Appurtenances articles 10.6.8 and 10.6.8.1. Look in index A at the notes for these two sections and it will explain that the underground pipes cannot be used as an electrode but they should be "bonded and grounded" as per NFPA 70.
 
RICK NAPIER said:
I think you can find a better explanation in NFPA 24 Standard for Installation of Private Fire Service Mains and their Appurtenances articles 10.6.8 and 10.6.8.1. Look in index A at the notes for these two sections and it will explain that the underground pipes cannot be used as an electrode but they should be "bonded and grounded" as per NFPA 70.
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I just went through a long discussion with our State (TN) Fire Marshall's office and was provided the same information: "You must not use the sprinkler system as a grounding electrode, but it should be bonded".
It remains a concept that escapes me. If you have 10 ft of metallic pipe in contact with the earth and you "bond to that pipe" does it not meet the requirements of a grounding electrode.
I could not get it across to folks I describe as "brain dead bureaucrats" that the piping in contact with the earth makes it an electrode so, if you bond to it, how can you not make it a grounding electrode connection.
 
RICK NAPIER said:
It is much the same as they treat gas pipin. You can bond it per 250.104 but you can't use it as an electrode per 250.50.
Click to expand...
But in the case of the metal underground gas pipe, the gas utility uses a dielectric fitting at the meter so that the required bonding of the interior gas piping does not cause the underground portion to become a grounding electrode (although around here this is no longer an issue as the underground piping is all non-metallic). There is not a similar fitting used on the sprinkler supply piping so a connection to the interior piping makes the underground piping a grounding electrode.
 
Aside from the physical realities, it doesn't officially become an electrode until within 5' of entrance to the building, except with the Exception of 250.52(A)(1).
But sometimes it's hard to teach electrons those subtle distinctions.
 
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