Eletrical Grounding

[nycpipewelder]

I work in NYC I am a plumber and have allways seen the electrical service grounded to the water main. Now keep in mind I work in new construction high rise buildings I have gone to this new job and the electrical contractor will not give a reason why he has not bonded his service to the water main except citing re cent code changes now I have been in a few buildings since the changes here and all have there services bonded to the water main! I even fought with one contractor in 2 buildings about him trying to bond to the gas service can any one give me info because I feel this is a dangerous thing happening

 

[wareagle]

Check hee for more informaton

http://www.mikeholt.com/codeForum/index.php

 

[alehman]

A connection from the main service disconnect ground bus to the water service (at a point no more than 5ft from the entrance to the building) is required by the National Electrical Code. I'll check my New York City code book on Monday.

A connection to gas piping is not required by any code to my knowledge.

 

[davidbeach]

Without actually checking the code, I believe that the piping material enters the consideration. Not much point grounding to a water main that is all plastic underground.

 

[nycpipewelder]

The water main is a six inch ductile iron main . And as far as the bonding to the gas service if we install a steel service line then we install anode bags on it to prevent grounding eating away at the pipe also when a steel gas service is installed two things are done one is a die-electric gasket and bolt kit is installed at the head of the service and the utiltiy company performs a voltage test on the main to insure it is insulated from the ground by shooting 30,000 volts if a section is not wrapped properly you see the sparks hit the soil I thank all of your information nycpipewelder

 

[stevenal]

250.104(B)requires all metallic piping likely to become energized, including gas, to be bonded.

 

[alehman]

Stevenal - I had forgotten that requirement. Not sure I can think of a situation where gas piping would be 'likely to become energized'.

 

[BobbyNewmark]

"Not sure I can think of a situation where gas piping would be 'likely to become energized'."

Kitchen range with electric igniters, bathroom heater in steamy room used by wet barefoot people, etc.

 

[itsmoked]

Gas furnace.
Swimming pool gas water heater.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[EEJaime]

Absolutely true Itsmoked,

Things such as:
-Packaged Gas-Electric Air Conditioning units
-Gas Clothes Dryers
-Gas Barbeque with electric strike start
-Gas fired water heater connected to Jacuzzi/pool/Sitz bath pump systems
-Natural gas fired sterilizers in hospitals
-Commercial laundry tunnel washer/dryer systems
-Gas fired power generation equipment

There are numerous pieces of equipment where gas connectons and electrical connections enter adjacent to each other. This is very common in many healthcare, industrial and commercial facilities.

We always bond natural gas piping systems. They are not used as a grounding electrode, they are just bonded to assure that should an accidental fault occur, there is a path to dissipate the energy.

 

[alehman]

Interesting. I can't recall seeing bonding jumpers to gas piping and never specified it myself. Maybe it's time to re-evaluate.

I wouldn't have thought to consider that as likely to become energized because it seems to me in most cases the piping is effectively connected to the frame of the appliance via it's fittings. Is a bonding jumper always required? I don't do healthcare facilities, but could understand those having more stringent requirements.

 

[alehman]

Further discussion of this subject can be found here -

http://www.mikeholt.com/code_forum/showthread.php?t=80492&highlight=energized

 

[stevenal]

By my read of the code section, it seems that the ground wire for any of these electric/gas appliances may serve the function if sized properly. I once checked continuity from ground prong to gas connection on a gas dryer. It was continuous, even through the flexible gas hookup. In the end the AHJ decides.