The use of metallic water piping as part of a building's electrical grounding system has been
a commonplace practice for more than 80 years. When electrical transformers serve multiple
buildings, the water services and distribution piping can act as parallel neutral return paths
for stray current from building electrical systems to the transformers. Electrical resistance in
pipe connections, if present, forces some fraction of the stray current to flow through the
parallel water path. Discharge of current on the inside of the pipe increases metal release.
Previous studies on the effects of grounding on water quality and metal release did not
investigate the effects of resistance or dielectric fitting. This study investigated the effects of
dielectric fittings on water quality. Copper tubing that had been modified with inserted
dielectric fittings was filled with
potable water from two different
water sources and was tested with
applied alternating current (AC)
voltages of up to 123 V for periods of
up to 110 h. Significant increases in
copper, lead, and zinc in stagnant
potable water were measured in less
than 24 h at applied voltages of ~50
VAC. Metal release generally increased
with charge transfer, in
accordance with Faraday's law.
Includes 13 references, tables, figures.
| Edition : | Vol. 94 - No. 5 |
| File Size : | 1
file
, 480 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 05/01/2002 |
