5044 B U Bowman Dr #102 ::: Buford, Georgia 30518
e-mail firstname.lastname@example.org ::: Phone: 678.546.6780
There have been a number of changes to the National Electrical Code. These changes were effective August 2nd, 2001.
These changes are not complicated, but based on input we've been getting from salesmen and distributors, there is some confusion. Some of this confusion is natural...some of it is the result of manufacturers supplying their distributors faulty information.
We will try to explain the changes very simply. At the bottom of this page you will find exact quotations from the 2002 National Electrical Code. Do not take our word for anything...please. You can order your own copy of the NEC from:
or call 1-800-344-3555.
PLEASE NOTE THAT THERE ARE DISTINCT DIFFERENCES BETWEEN THE NATIONAL ELECTRICAL CODE AND UNDERWRITERS LABORATORIES LISTING REQUIREMENTS.
1. Underwriters Laboratories does not regulate manufacturers, but manufacturers, for all practical purposes, need to submit equipment for listing. Underwriters Laboratories requirements are not binding on consumers.
2. The National Electrical Code is binding upon most consumers, but does not regulate what Manufacturers build. A manufacturer may build and sell an unlisted product, but penalties for improper installation fall upon the installer and the consumer...not the manufacturer.
IT IS IMPORTANT TO UNDERSTAND THAT UNDERWRITERS LABORATORIES AND THE NATIONAL ELECTRICAL CODE ARE TWO COMPLETELY DIFFERENT ORGANIZATIONS, WITH TWO COMPLETELY DIFFERENT PURPOSES.
DO NOT BELIEVE ANY MANUFACTURER WHO TELLS YOU THAT BECAUSE REQUIREMENTS DEFINED BY UNDERWRITERS LABORATORIES DO NOT BECOME EFFECTIVE UNTIL THE MIDDLE OF 2003 THAT YOU CAN IGNORE THE NATIONAL ELECTRICAL CODE REQUIREMENTS THAT HAVE BEEN IN EFFECT SINCE THE MIDDLE OF 2001.
YOU...DISTRIBUTORS, SPECIFIERS, INSTALLERS, AND CUSTOMERS, ARE AT RISK...NOT THESE MANUFACTURERS.
The NEC requires that a surge suppressor or a surge arrester be a "LISTED" device. This is a very specific qualification.
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In UL's own words, "A UL Listing Mark on a product is always composed of four elements: the "UL" in a circle Mark, the word "LISTED" in capital letters, an alpha-numeric control number, and the product name (e.g., "toaster" and "portable lamp"). Sometimes the UL file number is used as company identification."
An Installer must now assure that the device he is installing has a greater MCOV (Maximum Continuous Operating Voltage) rating than the electrical service he is installing equipment on.
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The only practical way an installer (or a specifier, or a dealer) can know this is if the MCOV is prominently displayed on the device label. The MCOV is not a rating that is simply stated by a manufacturer...it needs to be "earned. If a manufacturer adds this information after-the-fact it is not likely that the device is truly compliant.
An Installer must now assure that the device he is installing has a greater "fault current rating" (also called a "short circuit interrupting rating" and expressed as "AIC") than the equipment he is installing the device on.
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Again, the only practical way an installer (specifier, or dealer) can know this if it is prominently displayed on the device label.
A device rated as a surge suppressor can only be installed on the LOAD side of the electrical service.
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We have heard of manufacturers who recommend (in the field...not in writing) that their surge suppressors be installed on the "service" side at the service entrance. This is not in compliance unless the device is also rated as a surge suppressor.
Please note: Stedi-Power Equipment is rated as both a surge suppressor AND a surge arrester. For this reason, we specify that our equipment be installed on EITHER side of the service entrance...."service side" or "load side".
Double-Lugging, or the practice of installing more than one wire in a terminal on a breaker or terminal is prohibited.
GO TO REFERENCE
Many manufacturers recommend that you install their equipment on a circuit breaker within the service panel. They do not warn you that installing on a breaker in current use (it already has wires attached) may not be a "legal" installation. In fact, we've seen documentation in the field that illustrates exactly such a circumstance.
It is only allowed if the terminal is specifically marked as being qualified to accept multiple conductors. Most installations are not routinely "specified" for such equipment...and many panels have no "free" locations to install new breakers.
Our own experience is that electrical and building inspectors in the field routinely cite any connections of this type they see regardless of the suitability of the terminals for such service. This is not correct, but it requires "arguing" with the inspectors.
Below are quotations of passages from the 2002 NEC.
Again, please do not take our word for anything...Get YOUR COPY OF THE CODE HERE:
or call 1-800-344-3555.
EXCERPTS FROM THE NATIONAL ELECTRICAL CODE
Issued by the Standards Council on July 13, 2001, with an effective date of August 2, 2001, and supersedes all previous editions.
Approved as an American National Standard on August 2, 2001.
NOTE: This "new" standard is not really "new". It has been out for over a year now. There is really no excuse for having equipment on the market that cannot be installed without violating the National Electrical Code
A TVSS shall be a listed device.
our note: This means that the device must be listed with Underwriter's Laboratories. Not "recognized", Not "approved"....LISTED.
Equipment Connected to the Supply Side of the Service Disconnect.
Only the following equipment shall be permitted to be connected to the supply side of the service disconnecting means:
(3) Instrument transformers, (current and voltage), high impedence shunts, load management devices, and surge arresters.
NOTE: You MUST be rated as a SURGE ARRESTER to be installed on the "line" (or "supply" or "service") side of your main disconnect.
ALL Stedi-Power products are rated as BOTH "Surge Arresters" and "Transient Voltage Surge Suppressors".
There are very good reasons you want your product to be proven capable and flexible enough to mount in both of these locations.
ARTICLE 285 TRANSIENT VOLTAGE SURGE SUPPRESSORS
285.3 Uses Not Permitted
A TVSS shall not be used in the following:
(3) Where the rating of the TVSS is less than the maximum continuous phase-to-ground power frequency voltage available at the point of application.
NOTE: This means your device must be RATED for this "MCOV" or "Maximum Continuous Phase-to-Ground Power Frequency Voltage". This is a REQUIREMENT for "surge arresters". It isn't something that the "manufacturer" supplies....it is a RATING that has to be EARNED. This information is available at the UL website.
If it does not have an MCOV rating....it isn't legal to install...period. Why? No rating equals ZERO.
285.6 Short Circuit Current Rating.
The TVSS shall be marked with a short circuit current rating and shall not be installed at a point on the system where the available fault current is in excess of that rating.
NOTE: This fault current rating MUST be on the label. If it isn't, it's impossible to determine if the fault-current-rating is as high, or higher, than the panel you're installing it on. If it isn't there....it cannot be installed in compliance with the NATIONAL ELECTRICAL CODE...PERIOD.
Remember, even UNDERWRITERS LABORATORIES UL will requires this, but this requirement is not mandatory until June of next year. Unfortunately for people hoping to take advantage of this....remember, the NATIONAL ELECTRICAL CODE IS IN EFFECT NOW......
III Connecting Transient Voltage Surge Suppressors
Where a TVSS is installed, it shall be connected as follows.
(1) Service Supplied Building or Structure. The transient voltage surge suppressor shall be connected on the load side of a service disconnect overcurrent device required in 230.91
(2) Feeder Supplied Building or Structure.&nb sp; The transient voltage surge suppressor shall be connected on the load side of the first overcurrent device at the building or structure.
Exception to (1) and (2): Where the TVSS is also listed as a surge arrester, the connection shall be as permitted by Article 280.
NOTE: This is simply a clarification of what is seen in numerous locations throughout the code. If you are on the "Utility" side (called more commonly the "Line" or "Service" side) of the main disconnect...your equipment MUST be rated as a surge ARRESTER.
Article 110.14 Electrical Connections
(A) Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. Connection by means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller conductors.
Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.
NOTE: This information is included here because it is peripherally connected and we have had questions concerning this aspect of installation, as well.
The practice of installing more than one conductor (wire) in a terminal is called "double-lugging". Misunderstanding the requirements regarding "double-lugging" causes multiple problems if installers are not trained properly.
We have placed this here because some limitations of installing because of inability to meet the requirements above (ability to install on the line-side of the service entrance) may require double-lugging, and some people are claiming that double-lugging is illegal.
Unlike some of the hysteria we've seen..sometimes even posted by people calling themselves "building inspectors"...DOUBLE-LUGGING IS NOT ILLEGAL. IT IS LEGAL IF IT IS DONE PROPERLY AND THE EQUIPMENT IS RATED FOR THIS PURPOSE.
We train our installers in the specific requirements. You can be assured we will not instruct our people to install equipment in this manner unless it is FULLY compliant with the code.
We do this for YOUR protection, of course....but we also do it for OUR protection.
We hope this may be helpful to you. Good luck.
PHONE: (678) 546-6780 FAX: (678) 546-6782
5044 B U Bowman Drive #102
Buford, Georgia 30518
PHONE: (678) 546-6780
Last Updated: 07 Jun 2004
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