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September-October 1998
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September-October 1998 CoverSeptember/October 1998

TABLE OF CONTENTS

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Features

Services for Multi-Occupancy Buildings

by J. Phillip Simmons

We published a photograph in the "Code Violations” section of the March/April 1995 IAEI News which shows 21 service disconnecting means that are grouped in the same location on the end of an apartment building. Four service laterals supply the building from a common transformer. The caption with the photograph indicates that the installation is in violation of Section 230-71(a) of the National Electrical Code® as there are more than six disconnects grouped at the same location. Read more


Beinvenidos Mexico

Mexican electrical inspectors must now comply with accreditation, much the same as the ISO 9000.
Read more

The Grounding Electrode

by Peter Boden

Plastic piping is not only widely used in new installations, but also in repairing existing installations. Even in a metal water piping system, maintenance and repairs can introduce plastic pipe fittings that interrupt the electrical continuity of the system. These fittings can also significantly reduce the length of piping that can act effectively as a grounding electrode. Water utilities do not commonly install jumper wires around the fittings to maintain electrical continuity. In fact, many utilities discourage the connection of buried parts of metal water piping systems to the electrical system. They say that electric current through the pipe can hasten corrosion and affect the taste of the water. Read more

Departments

Canadian Code

Substation Grounding

by Leslie Stoch

Not long ago I wrote an article on Substation grounding for Electrical Business that raised the issue of whether one should interconnect the building reinforcing steel with the station ground electrode. A reader responded with the question of whether the best approach might be to ignore the rebar bonding. The reader is well justified in wondering whether the best approach might be to ignore the rebar bonding. The reader is well justified in wondering whether there is not an easy answer to his question as there may not be a precise answer for every possible situation. Read more

The Other Code

Overhead Line Design from Scratch—Part 4

by David Young

In Part 3 (July/August issue) we determined the height of our structures and the strength of our structures and foundations to comply with the National Electrical Safety Code® (NESC®). The last step in the design of a high-voltage overhead line up to 50 kV to comply with the NESC is to design the guying. Stringing conductors between poles puts tension on the poles. Though poles and foundations can be designed with enough strength to hold the tension, guying is much more economical. Read more

UL Question Corner

Outlet boxes for Ceiling Fans

by Underwriters Laboratories

Question: For outlet boxes that support ceiling suspended fans, does UL consider out-of-balance fans? Read more


Variations in Exit Signs

by Underwriters Laboratories

Question: I’ve noticed that the color, size, and visibility of exit signs varies greatly. Do UL requirements permit these variances? Read more


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