The National Electrical Code (NEC) – or NFPA 70 – was updated in 2011, as part of its 3-year change cycle. The NEC is published by the National Fire Protection Association (NFPA), and is commonly adopted by U.S. state or local political subdivision, and enforced by the Authority Having Jurisdiction (AHJ).
Many NEC requirements refer to “listed” or “labeled” devices, as defined in Article 100 of the NEC. The NRTL (Nationally Recognized Testing Laboratories) program accredits those organizations – like MET Labs – that, by whose labeling, the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
Following are some of the key changes that were incorporated into the 2011 edition:
- 110.24 Electrical service equipment must now be marked in the field, with the maximum available fault current at the incoming terminals of the equipment and the date that the fault current calculation was made.
- 110.3(A)(1) Any special conditions that may be essential to the safe use or functioning of the equipment could be included as a part of the listing and labeling.
- 200.4 Neutral conductors shall not be shared unless they are specifically permitted to be shared, as indicated elsewhere in the code.
- 210.8 Ground-fault circuit interruption for personnel are required to be installed in a readily accessible location.
- 210.8(B)(5) GFCI receptacles are now required to be used near sinks in healthcare facilities. Exception No. 2, for receptacles located in patient bed locations of general care or critical care areas of health care facilities other than those covered under 210.8(B)(1), GFCI Protection shall not be required.
- 210.12(A) Types MC (metal clad) and, steel armor type AC (armor clad) cable may now be used between the panel and the first device, when arc-fault circuit interrupter (AFCI) protection is required for that circuit.
- 210.12(B) When modifications or extensions are made to an existing branch circuit in a residence and the code requires that the area have AFCI protective devices, the modified or extended branch circuit must now have an AFCI device installed.
- 230.44 If cable trays contain service entrance conductors (types SE (service entrance), MC, MI (mineral insulated), and IGS (integrated gas spacer)), then the trays must be labeled with the wording “Service Entrance Conductors.”
- 250.92(B) Bonding conductors are required around reducing washers and concentric or eccentric knock-outs for all service entrance conduit connections at the service entrance equipment.
- 300.4(E) Cables, conduits, boxes, and other raceways are not permitted to be installed closer than 1½” in exposed or concealed locations under metal-corrugated sheet roof decking.
- 300.5(C) Type MI and MC cables that are listed for direct burial or in concrete are permitted to be installed within the concrete, below buildings.
- 300.11(A)(1)(2) When independent electrical equipment support wires are installed within dropped-ceiling areas, they shall be distinguished by color, tagging, or other permanent effective means.
- 300.50(B) The interior of underground raceways shall be considered to be wet locations. Therefore, any connections and splices shall be approved for wet locations.
- 310.10(H)(1) Conductors smaller than 1/0 are no longer permitted to be paralleled for increased ampacity.
- 348.42 angle connectors for flexible metal conduit (FMC) are not permitted to be concealed.
- 392.18(H) Cable trays containing conductors over 600 volts are now required to be marked “Danger–High Voltage–Keep Away”.
- 406.4(D)(5) For installations in which tamper-proof receptacles are required and receptacles are being replaced, the installer is now required to install “listed” tamper-proof receptacles.
- 406.13 Tamper-resistant receptacles are now required in all guest rooms and guest suites.
- 410.16 Luminaires in clothes closets are permitted to be either surface or recessed LED, with completely enclosed light sources, fluorescent, or totally enclosed incandescent fixtures.
- 410.130(G)(1) For existing installed luminaires without disconnecting means, at the time a ballast is replaced, a disconnecting means shall be installed.
- 450.14 Transformers other than Class 2 or Class 3 are required to have line-side disconnecting means within sight of the transformer, or the disconnecting means must be lockable, and the location shall be field marked on the transformer.
- 500.2 A definition has been added to define the parameters, or make up of, combustible dusts.
- 501(B)(5) This new code paragraph clarifies the differences between Class 1, Division 1, and Division 2 installations, where metallic conduit does not provide sufficient corrosion resistance, listed flexible conductors, factory elbows and associated fittings shall be permitted, where restricted public access and only qualified persons service the equipment.
- 517.13(B) The requirement for redundant grounding conductors has been clarified and states that the insulated bonding jumper from the metallic box to the equipment grounding conductor is permitted.
- 517.16 Isolated ground receptacles are not permitted to be installed within any patient care areas.
- 517.17(B) If there is only one level of overcurrent protection between the incoming service entrance and transfer switches, the second level of ground fault protection that is normally required for healthcare facilities shall not be installed downstream of the transfer switches.
- 517.18(A) Receptacles in patient bed locations shall not be a part of a multi-wire branch circuit (i.e., have a neutral in common with another phase conductor).
- 517.160(A)(5) Conductors for an isolated power system shall be identified by a continuous, distinctive colored stripe other than white, green, or gray along their entire length.
- 547.5(G) For engineers designing barns, the code no longer permits deleting GFCI protection on an outlet for a piece of dedicated equipment when that piece of equipment is within 3’ of another GFCI outlet.
- 620.53 Exception: Disconnects are required for elevator cab lights and ventilation, but if the ventilation motor is less than 2 HP or less an 300 volts, a general-use snap switch may be used as this disconnecting means.
- 645.17 The requirements for power distribution unit (PDU) panelboards used for information technology equipment, shall be permitted to have multiple panelboards within a single cabinet, if the power distribution unit is utilization equipment and is listed for information technology application.
- 690 Due to the wide popularity of photovoltaic (PV) systems, broad changes have been made in this section.
- 694 A new article to address wind-powered electric generating systems.
- 695 The code for electrically driven fire pumps has been modified to closely correlate to the requirements of NFPA 20.
- 700.10(D)(1) Feeder circuit cables for emergency systems must now be rated for a minimum 2 hours fire rating.
- 700.27 Exception: Selective coordination is no longer required for overcurrent devices that are installed in series if no loads are connected in parallel with the downstream device.
- 701.6(D) There is now a requirement for ground fault indication for legally required standby systems of 150 volts to ground and circuit protective devices rated 1000 amperes, which is similar to that previously required only for emergency systems.
This list was modified from a more detailed list featured in Consulting-Specifying Engineer.
For Canada, the Canadian Electrical Code was updated for 2012.
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I understood that the need to label the entire box and associated components as an aggregat is more for boxes that are “cookie cutter” designs. For example, a starter panel that might accompany an air compressor would be subject to this code. There would be thousands of these, they would all be exactly the same and they would accompany the air compressor. As an electrical engineer I appreciate the need and the intent. On the other hand, the panels that are custom made for field applications, vary depending upon the specific field situation. we build, for example, boxes for gas distribution telemetry. They may fall into 6 or 7 categories but even if all categories were reviewed and labeled, anytime we replaced an RTU (the intelligent devices inside) with a newer one or were forced to replace a power supply with a different one or replace the pressure transducer or add a new pressure transducer, and so on, the label would be for naught. The point is that this is an impractical requirement as applied to panels and boxes maintained in the field. I have been led to an exception for field panels in The NEC.
In the NEC 2011 Chapter 4 Equipment for General Use: ARTICLE 409 Industrial Control Panels
III. Construction Specifications
“In addition to the field supply wiring requirements for all control panels contained in Part II, construction requirements for control panels are covered in Part III of Article 409. The Code does not require that control panels be listed, and Part III provides the authority having jurisdiction with a set of requirements that can be used as a benchmark for approval of a field-constructed control panel.”
In my NEC 2011 book this paragraph is in a grey shaded box which reflects commentary. He said that this is fairly new and that even he would not have been aware of the exception except for stumbling upon it.
Am I interpreting this exception correctly? If so can that be added to your 2011 points of clarification?
No, your interpretation is not correct. In regards to a Control Panel manufactured under UL 508A, Industrial Control Panels, there has to be some leeway given in that these control panels are custom built. If the category for the control panel is intended for an unclassified area, then 508A is the correct safety standard to be adhered to. If the Control Panel is to be utilized in a classified area, then UL 689A will be the Safety Standard of choice. And the list goes on, for Intrinsically Safe equipment and so on. I understand the confusion of whether the control panel must be Listed or Labeled per the NEC Article 409.
If the equipment is intended for an Intrinsically Safe application, then the NEC Article to be reviewed would also be 504, in which case Article 504.4 would take effect, to which, being Listed.
Here is where the entire code must be reviewed; if Article 110-3 (A) & (B) is reviewed, you will observe that all electrical equipment must be examined, for construction, suitability for use and proper component selection. These standards are specific in nature and when Field Evaluated, that investigation is site specific, as well as the documentation to capture all data in regards to construction, correct grounding & bonding and overcurrent selection is made at time of manufacture. When a Field Evaluation Label is placed on the equipment, the electrical data is compiled and kept for record keeping.
If any component has failed for whatever reason, and you need to replace it with a like component and same electrical rating, then there is no need for another Field Evaluation on the product. If however you change out components which were not part of the original investigation, or added components which change the overall electrical rating of the equipment, then a new investigation will have to done.
As with any electrical product, the AHJ, Authority Having Jurisdiction will have the final say as to whether a control Panel still meets the original investigation.