Infrastructure Codes and Standards-the National

Electrical Code® and DC PowerMark W. Earley, P.E.

Chief Electrical Engineer

Also known as the NEC ® or ANSI/NFPA 70 There are two electrical codes that govern electrical

installation◦ The National Electrical Safety Code®-governs electrical

and communications utility installations◦ The National Electrical Code®-governs electrical

installations in the built environment

What is the National Electrical Code?

History First meeting held in 1896

◦ Five Codes in use in the USA at the time

◦ Intended to promote safety and facilitate product standardization across the country

First edition issued in 1897 NFPA became sponsor in 1911

and has continued to be the sponsor for 100 years

There have been 52 editions Since 1953, the NEC has been

issued every three years Adopted into law

Adoption of the NEC

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Adoption of the NEC

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NEC TCC

CMP 1

CMP 1 TG

CMP 19

CMP 19 TG

NFPA 70B

NFPA 70E

70E TG

Organization of NEC Project

The NEC TCC has responsibility for 19 Code-Making Panels plus several other Technical Committees and documents, including NFPA 70B, 70E, 73, 79, 110, 111, 790, and 791.

NFPA 70B-Electrical Equipment Maintenance NFPA 70E-Electrical Safety in the Workplace NFPA 79-Industrial Machinery NFPA 110-Standard for Emergency and Standby

Power Systems NFPA 111- Standard on Stored Electrical Energy

Emergency and Standby Power Systems NFPA 790- Standard for Competency of Third

Party Field Evaluation Bodies NFPA 791- Recommended Practice and

Procedures for Unlabeled Electrical Equipment Evaluation

Other Applicable Standards

Electrical installation requirements--NEC® Product standards -UL, NEMA, etc

◦ Product testing to standards Electrical inspection (ensures compliance

with the installation rules of the NEC, along with any product installation requirements

The Three Leg Stool

Have been in every edition since the 1897 edition.

There are specific AC and DC requirements Where not specified, requirements apply to

AC and DC

DC Requirements

AC Systems DC Systems

The NEC Applies to AC and DC

AC Requirements

DC Requirements

Article 480 Batteries Article 690 PV Systems Article 725 Class 1, 2, and 3 Systems Article 760 Fire Alarm Systems Article 800 Communications

Most Common DC Applications

Are the Common Requirements a Good Idea?◦ Based on current applications, yes!

Based on current technology, the requirements of the NEC have worked well.

◦ Higher power DC may present new challenges Overcurrent protection GFCI protection AFCI protection Switching Circuit protection Arc flash evaluation Circuit separation

Thoughts to Ponder

Standard nominal AC line voltages◦ 120/240 Volts single phase◦ 208Y/120 Volts three phase◦ 480Y/277 Volts three phase

Standard nominal DC Line voltages◦ ?◦ 380 volts

Demand factors Plug and receptacle configurations?

Thoughts to Ponder

If DC is produced by switching mode supplies, will there be nonlinear load problems?◦ Neutral conductor size for AC services, feeders,

and branch circuits◦ Electronic noise◦ Isolated grounding

Thoughts to Ponder

Chaired by John Kovacik, UL Members from various parts of the NEC

community May be soliciting additional members with

DC expertise

NEC TCC Task Group on DC

Anyone can submit a proposal or public comment

Committee meetings are open Anyone can request time to address a code-

making panel Committee reports are published

The NEC has an Open Process

Jan. 9-21, 2012

April 23-27, 2012

June 15, 2012

Oct. 17, 2012Nov. 4, 2011 Nov 28-Dec

8, 2012

Proposal Closing Date NEC TCC Meeting Comment Closing

CMP ROP Meetings. ROP Published CMP ROC Meetings.

Critical Points in NEC Processing Schedule

Note: The Individual CMP meeting dates have not yet been established.

Thank you!It can’t happen without your input!