Bonding building metal piping systems
Bonding Pipes in Your Home or Business Property
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 bonding between all pipes ensures voltage (potential for current flow) cannot build between different piping systems, and that any voltage induced on the bonded system (for example, from a nearby lighting strike or from a damaged conductor in the building wiring system) will conduct to earth via a robust fault current path. Lightning-induced voltage will cause less damage when it has a robust path to earth, while circuit faults shorting to well-earthed piping will draw current through the circuit breaker to trip it, rather than remain a latent fault that could ignite a fire or shock or electrocute people.
System Grounding First
A robust path to ground from the piping systems is ensured only if the electrical service equipment has been properly grounded and bonded in accordance with National Electric Code (NEC). There should be a grounding electrode conductor (GEC) 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 the earth under or around the building. Such concerns do not arise often (or obviously) during normal use, but localized voltages resulting from lightning strikes, induced at-a-distance (without need for direct strikes) will cause less damage if local bonding in your building is thorough.
95% of existing construction homes in this neighborhood lack this important part of the building grounding system, which ensures that most or all metal in the house has a way to drain transient surges induced by nearby high-voltage lightning strikes. The high-voltage current flow of a lightning discharge to earth, perpendicular to some metal in the house, induces current in the metal, at-a-distance, even if the strike does not directly contact your building. Bonding of the metal piping systems minimizes induced voltages and the risk of fire.
Low Materials and Labor Cost
The materials costs for bonding metal piping systems are less than $30, while labor will typically be a service call of $65-100 (or DIY: ‘free’), or $25 if part of a work order $250 or more.
Up to parent:
- Flexible gas tubing (CSST) may be ruptured by lightning-induced discharge
- Suggestion: where CSST is used between sections of cast-iron pipe, perhaps a bonding jumper should be installed across the iron pipes to ensure most lightning discharge energy runs around the CSST rather than through it.
Off-site Links ->
- Annapolis Home Inspection, LLC Aluminum branch circuits, homes 1965-1972
- ComplianceAndSafety.com OSHA Electrical Safety Training
- Electric Monk TV (YouTube) Video channel for PhillyLicensedElectrician.com Robert Monk
- EnergyConservation HowTo A tinkerer genius discusses energy conservation and his ladder system for accessing the attic (where a lot of energy-saving work happens).
- PennFuture Energy Center Energy and energy efficiency news for the Commonwealth of Pennsylvania
- Phila area rife with building efficiency upgrade opportunities Philadelphia Inquirer article discusses recent study showing Philadelphia’s inner-ring suburbs stand to save from energy conservation retrofits.
- Philadelphia Row-house Manual A design, maintenance, and modifications manual for our most widely-used form of housing.
- Robert Monk Robert Monk’s personal blog
- SolarCities (DOE) Solar PV Levelized Cost Interactive Comparator Simple graph compares ‘levelized cost’ of energy from solar PV to conventional grid rates, with a time-slider interactive feature.
- The Circuit Detective – Solve Home Electrical Problems Yourself! Electrical troubleshooting procedures pitched to homeowners.
- The Energy Co-op Blog from a leading alternative energy provider in PECO territory, includes fun conservation tips.
- Weatherization: the anti-Solyndra Salon.com article praising the continued success of the federal Weatherization Assistance Program (WAP), low-income energy-savings and job-creation.
- West Philly Tool Library Official site of WPTL, Philly’s own community tool lending library: like a book library, but tools!
- WestPhillyLocal .com Site name say sit all.
- Bartram's Gardens Founded in Philadelphia’s colonial era, today the gardens continue pioneering in horticulture and agriculture with a variety of herbs, trees and other vegetation in an arboretum/gardens on the Schulkill River banks, and a new farm abutting sadly neglected
- HiddenCity Philadelphia Surprising places it takes an adventurer to discover; events, too.
- Philly Household Hazardous Waste Drop-off Schedule City of Philadelphia dates and places for disposing of spent batteries, CFL lamps, unused paint and cleaning products, etc. LovePhilly: don’t pour these in the drain or send them out with the trash.
- Reading Terminal Market Purveyors of fine foods and foodie stuff, all under one roof downtown under the PA Convention Center
- Secret Garden on the Rails Jacques-Jean Tiziou shows some dramatic natural and urban and naturalized-urban scenes along abandoned rails of Philadelphia
- Sketch Burger, Fishtown A vegan-friendly burger joint with a #1 in Philly contender beef burger, best fries that somehow stay fresh for 1/2 hour while you tackle burger, and a vegan cafe vibe of friendly folks.
- WXPN: Philly sings in key of love Love songs by Philly artists