Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Send questions to firstname.lastname@example.org. Answers are based on the 2017 NEC.
Marking reconditioned equipment
Over the last 15 years, we have been purchasing reconditioned equipment for several of our industrial customers. This is the only option we have because, in most cases, equipment such as busway, bus plugs and circuit breakers are no longer being manufactured and cannot be purchased new. There is a revision in the 2017 NEC that affects the marking of reconditioned equipment. How will that impact our installations?
During the 2017 NEC revision cycle, a new informational note was added in Section 110.3(A)(1) to clarify that equipment is permitted to be new, reconditioned, refurbished or remanufactured. In addition, Section 110.21(A)(2) was added to require reconditioned equipment to be marked with the name, trademark or other descriptive marking of the organization responsible for reconditioning of electrical equipment. The date that the equipment was reconditioned must also be included in the marking. This new requirement clarifies that the suitability of the reconditioned equipment is not permitted to be based solely on its original listing. This places the responsibility of suitability on the organization that reconditions the equipment.
If an installer chooses to purchase and install reconditioned equipment, it is their responsibility to ensure the equipment is properly marked. This includes the marking of the organization that performs the reconditioning and the date the equipment was reconditioned.
The act of reconditioning means to extend the equipment life and, in some cases, may include adding new performance- and safety-driven features. It is imperative that the organization that reconditions the equipment obtain all pertinent information on the equipment’s original use. This includes the installation date, service records, environment and application where the equipment was originally installed.
This information is essential to determine suitability. For example, a significant amount of electrical equipment is being removed at this time due to exposure to floodwaters, which renders most of that equipment unusable. A significant amount of equipment cannot be reconditioned. See the National Electrical Manufacturers Association (NEMA) policy on reconditioned equipment, which provides prescriptive lists of equipment that may and may not be reconditioned.
For example, molded case circuit breakers cannot be reconditioned. The NEMA policy provides extremely valuable information. It goes a step further and suggests the third-party certification mark be removed or obliterated from reconditioned equipment. Removal of these markings is the most effective way to meet the NEC requirement prohibiting approval of reconditioned equipment based on the equipment’s original listing.
The installation of generators for optional standby systems can get complicated when we consider the type of fuel and how long the system needs to operate. Natural gas is not always available, and owners do not want large propane tanks in their backyards. We are now looking at stationary lithium-ion batteries as a standby power source. We have been told these stationary batteries are considered stand-alone and the rules that apply to automatic and manual transfer for optional standby systems do not apply. Is that true?
No, the rules in Section 702.4 for capacity and rating of optional standby system equipment apply. Article 100 defines a stand-alone system as “a system that supplies power independently of an electrical production and distribution network.” For batteries used as a source for an optional standby system to be considered stand-alone, they would have to be external to and not part of or controlled in any manner by a power production, distribution and utilization system, such as a utility system. In this type of installation, the batteries would be charged and controlled from power supplied by the utility system.
The requirements in 702.4(B)(1) for manual transfer equipment and 702.4(B)(2) for automatic transfer equipment apply. If batteries are used as an optional standby source with automatic transfer equipment, they must be sized to handle the full load that is transferred, or a load management system must be installed to automatically manage the connected load. The use of batteries as a source for optional standby systems will likely drive revisions to clarify this issue in the NEC. See Section 690.2, which contains definitions to clear this up with respect to solar photovoltaic (PV) systems.
“Stand-alone system” is defined as “a solar PV system that supplies power independently of an electrical power production and distribution network.” Additional clarity is provided by the definition of “electrical production and distribution network” as “a power production, distribution, and utilization system, such as a utility system and connected loads, that is external to and not controlled by the PV power system.”
Identifying grounded conductors
Where more than one nominal voltage system is present in a building, am I required to label the colors used for grounded conductors similar to the requirement in Article 210 for ungrounded conductors?
Where branch circuits are supplied by more than one nominal voltage system, Section 210.5(C) requires ungrounded conductors to be identified by phase and system at all termination, connection and splice points. This requirement also mandates posting of the identification method and labeling at panelboards is a compliant option. The rule for grounded conductors is in Section 200.6(D) and requires identification to distinguish each system-grounded conductor only where grounded conductors of the different systems are installed in the same raceway, cable, box, auxiliary gutter or other type of enclosure.
If system-grounded conductors are installed together, the identification method is then required to be documented or posted on the distribution equipment, such as a panelboard.
At a recent electrical inspectors meeting, we discussed the requirements of Section 700.16, and we were completely confused. This requirement refers to the “failure of any individual lighting element.” Is the reference to “element” addressing an incandescent type lamp?
No. The term “element” is used often in the NEC to describe “a part of something” and is prefaced by much more than the term “lighting.” There are heating, sensing, conducting, protective, mechanical elements and much more. Section 700.16 contains multiple requirements. It is important to note that Article 700 does not specify where emergency lighting is required.
Informational Note No. 3 in Section 700.1 explains that NFPA 101, Life Safety Code, specifies where emergency lighting is considered essential to life safety. The key to understanding and applying the requirement you are referencing is the use of the phrase “total darkness.” Emergency lighting in a given area cannot depend on a single ballast, lamp or other “individual lighting element” that could cause a space to be in total darkness if it were to fail.
For example, if a single recessed 2-by-2 fluorescent type luminaire with two lamps and a single ballast is the only source of emergency lighting in a given area, it would be a violation. The loss of the ballast (which is an “individual lighting element”) in that luminaire would leave the space in total darkness. Where there is more than a single luminaire in a given area it would not be a violation. If one fixture were to fail due to the loss of the ballast, light levels would be reduced, but there would not be total darkness.
MI cable termination
A fire pump feeder we are installing in a commercial facility consists of individual 1/0 AWG copper conductors. We were asked for a detail on the termination of the mineral-insulated, metal-sheathed (MI) cable for the fire pump. Our submission was rejected. I learned that Section 695.6(H) prohibits single conductor MI from entering directly into the fire pump controller. In the past, we simply cut a rectangular opening in the controller and installed a brass plate that was drilled out to bring the individual MI cables into the controller to prevent induction in the ferrous metal enclosure. Why did the NEC prohibit that practice? Why do we now need a junction box between the MI cable and the fire pump controller?
The NEC does not have purview over the performance of electric fire pumps. See Section 695.1, Scope, where the informational note explains all text followed by a reference in brackets has been extracted from NFPA 20 2013, Standard for the Installation of Stationary Pumps for Fire Protection. NFPA 20 has purview over fire pump performance, and the NEC provides prescriptive installation requirements for the electrical installation only.
Section 695.6(H)(1) requires a listed electrical circuit protective system to terminate in a junction box ahead of the fire pump controller. This requirement is extracted from Section 18.104.22.168 in NFPA 20, which prohibits single conductors (individual conductors) from entering the fire pump enclosure separately. In this case, the extract reference is missing and needs to be added. After 695.6(H)(1), there should be a reference to the extract requirement in NFPA 20 [20:22.214.171.124]. Annex A in NFPA 20 provides the rationale for this requirement. Section A.9.8.1 explains that cutting slots or rectangular cutouts in a fire pump controller will violate the enclosure type rating and the controller’s short circuit (withstand) rating and voids the manufacturer’s warranty.