Metal Water Pipe Bonding in Classified Loc

[sparkyguy545]

Have a Non-Hazardous electrical room adjacent to Cl 1, Div 1, Gp D Classified Location. All Electrical distribution gear is installed in the non-hazardous location. Problem: All metal water pipe is located in the adjacent Classified location only and should be electrically bonded. How can this physically be done and still meet intent of NEC? If bonding jumper was routed through barrier wall it would require metallic conduit. Therefore it needs a seal-off @ the barrier wall. How can the bonding jumper be physically bonded to the conduit at both ends to satisfy 250.64. Another issue: what is done within the hazardous location for termination at the water pipe system? Is a standard pipe saddle-clamp used in the hazardous location? It wouldn't have a specific listing for the environment.

 

[rbalex]

Where/how have you established your grounding electrode conductor?

 

[sparkyguy545]

Concrete Encased Electrode (Ufer) in structure footing. Wastewater Treatment Facility. No building structural steel, all masonry building construction. Distribution Switchboard is located in the Non-Classified Electrical room. All process equipment, process piping, etc. is limited to the Hazardous location in the room adjacent, but separate from the Electrical room. Each area has individual exterior doors with no connecting passageways. Since facility classified location has metallic process area piping, it should be bonded back to the Grounding Electrode. However, the question of "how" has come up. Without extending outside the building, then back in, the methond of raceway routing of the bonding across the "boundary" becomes an intresting construction & Code issue; especially with regards to sealing.

 

[kameele]

I'm assuming that all this construction is done and you can't stub up a pigtail into the classified room. That would be too easy. are there other conduits with EGCs run into the room? 250.104(B) allows the EGC of the equipment that is likely to energize the piping to serve as the bonding jumper. But that appears to be for gas or process piping. Since this is not a potable water system, could it be considered as process piping?

Since I have to do this a fair amount I never miss an opportunity to go back over the grounding and bonding section. And now 250.100 has me a little confused as to how you would implement any of the three methods listed with water piping that would have no direct connection to the electrical system.

Sorry, but I seem to have come up with more questions than answers, :roll: but I hope I might be at least proceeding in the right direction. i look forward to more definate answers, too

 

[bobgorno]

Why use a raceway? Consider > #6AWG needs no raceway. Run a large SDBC conductor through the wall. Make sure the vapor-tight integrity of the wall is not compromised and connect to the piping using Burndy type GAR-BU or similar if you are <12" diameter pipe.