Bonding Metal Piping Systems.mov

See also:
http://www.phillylicensedelectrician.com/what-is-grounding-bonding/

Exposed metal piping systems in a building should have zero voltage between them, and a low-impedance path to ground. In many homes, all of this may be ensured by bonding hot and cold water pipes, and gas pipe, to each other where they converge at the water heater (if gas-fired). Contrary to popular belief, water is a poor conductor, and some fittings at or inside water heaters could insulate the hot and cold piping systems from each other. So intentional, solid metal connections between all pipes ensures a robust current path.

The path to ground is ensured ONLY IF THE ELECTRICAL SERVICE HAS BEEN PROPERLY GROUNDED AND BONDED. There should be a grounding electrode conductor from the service disconnect equipment to a metal water service entrance pipe (if metal and installed through earth), and to a supplementary driven ground rod or other electrode. Additionally, the connection to the water pipe should include a bonding jumper that maintains the connection, even if the water meter is removed for servicing. The electric service bonding connects the electric utility grounded conductor and the local grounding system to local earth, equalizing any voltage that might otherwise exist between the utility ground (potentially 100's of yards away) and local ground. Such concerns do not arise often (or obviously) during normal use, but localized voltages around lightning strikes, induced at-a-distance (without need for direct strikes) will cause less damage if local bonding in your building is thorough. Visit http://www.phillylicensedelectrician.com and/or http://www.facebook.com/pages/Robert-Monk-Electric/178274968869746?ref=ts for more tips and guides to your building energy systems.

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Tags:

• electrical
• electric service
• service equipment
• bonding
• grounding
• metal piping systems
• water meter
• bonding jumper
• water heater
• bonding at water heater