Post on 17-Dec-2015
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
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
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.