Significant Proposals for 2005 NEC Part III

As Reviewed by Mike Holt

Articles 215 through 220

The following text is a quick summary of the proposed changes for the 2005 NEC. This document is a work in progress and the Code panel will change many over the next few months. Some of these you might find important to your work and you might want to follow their progress with me. Therefore, each week I will email you a few of these changes.

Each proposed change has a Report on Proposal (ROP) number, like 1-25. This number reflects the Proposal Number and all action on this proposal can be viewed in the following PDF document NECPart1 [4.72 MB].

As always, I am looking to improve our products, so if you feel you have anything to contribute, please let me know at Mike@MikeHolt.com.

Article 215 Feeders

2-270
215.2 Minimum Rating and Size
(A) Feeders Not More Than 600 Volts
(1) General. New sentence requires the feeder circuit grounded (neutral) conductors to be increased in sized.

Author's Comment: Load calculations often result in a grounded (neutral) conductor that is very small in comparison with the required equipment grounding (bonding) conductor. Should a fault occur from a phase to a grounded (neutral) conductor, the grounded (neutral) conductor could be damaged before the overcurrent protection device opens.

2-289
215.12 Identification for Feeders
New section requires feeder conductors be properly identified.

Author's Comment: The text parallels the requirements for branch circuits as contained in 210.5(C).


Article 220 Branch-Circuit, Feeder, and Service Calculations

2-292
Many Code sections in Article 220 were renumbered.

I. General

2-294
220.1 Scope
New FPN with a figure showing the arrangement of Article 220 was added to help the reader better understand and use the requirements in this article.

2-298
220.3 Application of Other Articles
New section informs the reader that other Articles have requirements that may alter the calculations performed in Article 220.

Author's Comment: The new table should prove to be a useful tool for those who perform electrical load calculations per the NEC.

IV. Optional Feeder and Service Load Calculations

2-344
220.82 Dwelling Unit
(C) Heating and Air-Conditioning Load
(4) Heat Pump. The method of determining the dwelling unit calculated demand load for heat pump systems was changed.

Author's Comment: This is because the 2002 calculation resulted in a larger service size for a heat pump installation, when in reality the consumption was less.


Article 225 Outside Branch Circuits and Feeders

II. More Than One Building or Other Structure

225.30 Number of Supplies.
(A) Special Conditions
(6) Redundant Systems. New subsection added to permit more than one feeder or branch circuit to supply a building for the purpose of providing power for a "redundant system."

Author's Comment: A redundant system is not defined, but it might be an electrical system which supplies electrical power to one or more branch circuits which are also connected to another electrical system that supplies the primary electrical power to those branch circuits.


Copyright © 2002 Mike Holt Enterprises,Inc.
1-888-NEC-CODE (1-888-632-2633)