Significant Proposals for 2005 NEC Part IV

As Reviewed by Mike Holt

Articles 230 through 240

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 NEC Part1 [4.72 MB].

Article 230 Services

4-44a
230.2 Number of Services
(A) Special Conditions
(6) Redundant Systems. New subsection added to permit more than one service to supply a building for the purpose of providing power for a "redundant system."

4-77
230.44 Cable Trays
This section was revised to clarify the requirements for cable trays systems that contain service conductors, and when a solid fixed separation barrier is required.

4-90
230.71 Maximum Number of Disconnects.
(A) General. New text allows the disconnecting means used solely for transient voltage surge suppressors not to be counted.

Author's Comment: There have been buildings where a TVSS was not permitted, because six disconnecting means were already there for the service.

4-94
230.72 Grouping of Disconnects
(B) Additional Service Disconnecting Means. Rule revised to clarify that the service disconnecting means for "emergency systems," in addition to legally required or optional standby systems must be installed remote from the one to six service disconnecting means for normal service.

Author's Comment: Emergency Systems have the same importance as fire pumps and standby systems, so they should have the same safety precautions. This requirement should prevent unintended interruption of the supply.

4-105 and 106
230.82 Equipment Connected to the Supply Side of Service Disconnect.
(2) Meter Socket Transfer Switch. Subsection added to allow meter socket transfer switches to be installed ahead of the service disconnecting means.

Author's Comment: Not all transfer switches are permitted ahead of the service disconnecting means. Meter socket transfer switches must be designed for the fault current and meet the criteria for installation ahead of the main.

4-106
230.82 Equipment Connected to the Supply Side of Service Disconnect.
(3) Meter Disconnect Switch. New subsection permits the installation of a meter disconnect switch ahead of the service disconnect.

Author's Comment: This device enhances safety for utility personnel when meters are installed or removed.


Article 240 Overcurrent Protection

10-29
240.5 Protection of Flexible Cords, Flexible Cables
(B) Branch Circuit Overcurrent Device
(1) Supply Cord of Listed Appliance or Portable Lamps. Revised text attempts to clarify that the NEC only applies to premises wiring, not supply cord of listed appliance or portable amps,

10-29
240.5 Protection of Flexible Cords, Flexible Cables
(B) Branch Circuit Overcurrent Device
(3) Extension Cord Sets. Text revised to clarify that the NEC only applies to premises wiring, not extension cords.

Author's Comment: Overcurrent protection of extension cords is a product issue, therefore it rests with a qualified testing laboratories, such as Underwriters Laboratories Inc., (UL), not the NEC.

10-27
240.5 Protection of Flexible Cords, Flexible Cables
(B) Branch Circuit Overcurrent Device
(4) Field Assembled Extension Cord Sets. New requirement permit extension cord sets to be field made.

10-39
240.16 Circuit Breaker as a Disconnecting Means
Revised text prohibits nails, screws or wire to be used for circuit breaker handle ties. Now they must be designed by the manufacturer to perform its intended function.

10-47
240.21 Location in Circuit
(B) Feeder Taps.
(3) Taps Supplying a Transformer [Primary Plus Secondary Not Over 25 ft Long]. The wording of this section was changed to simplify the sizing calculation for secondary conductors supplied.

10-57
240.21 Location in Circuit
(C) Transformer Secondary Conductors. Clarify that an individual transformer can supply more than a single load.

10-62
240.21 Location in Circuit
(C) Transformer Secondary Conductors.
(6) Secondary Conductors Not Over 25 ft Long. The wording of this section was changed to simplify the sizing calculation for secondary conductors.

10-66 and 10-73a
240.24 Location in or on Premises.
(E) Not Located in Bathrooms. Revise text prohibits overcurrent devices to be located in bathrooms of guest suites, as well as guest rooms of hotels and motels.


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