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 .
What is an outlet?
We are having a debate within my company that I hope you can settle. Where a dishwasher is hard-wired in a dwelling unit, is ground-fault circuit interrupter (GFCI) protection required? Where there is no receptacle, there is no outlet. See 210.8, which states upfront that it applies to receptacles. When we hard-wire a dishwasher, the terminations are in the utilization equipment, and there is no outlet. I have installed dozens of hard-wired dishwashers with no GFCI protection, and the inspectors did not ding me for that once.
All requirements in the NEC require an in-depth understanding of defined terms. As the saying goes, if you can’t talk the talk, you can’t walk the walk. Section 210.8 contains parent text that requires GFCI protection for personnel be provided in accordance with first-level subdivisions (A) through (E). Additional general requirements include the installation of all GFCIs in a readily accessible location and prescriptive requirements on determining distance.
The parent text in each section provides the ground rules for all of the following subdivisions. Section 210.8(D), “Kitchen Dishwasher Branch Circuit,” mandates GFCI protection to be provided for all outlets that supply dishwashers in dwelling units. The term “outlet” is used throughout the NEC and must be understood to apply to any associated requirement. Wherever a branch circuit is involved, there is always an outlet. See the defined term “branch circuit.” For conductors to be a “branch circuit,” they must originate at the final overcurrent device and end at the outlet(s).
There are multiple types of outlets. See the definitions of lighting outlet and receptacle outlet. Both of these terms are tied to the definition of the general term “outlet,” which is defined as a point on the wiring system at which current is taken to supply utilization equipment. Where a branch circuit is hard-wired to utilization equipment, that connection is by definition an outlet. All dishwashers in dwelling units require GFCI protection without regard to how the dishwasher is supplied. This is a serious safety issue. While the inspector may not have failed your jobs, if an injury or fatality should occur due to end-of-life appliance failure or other reasons, the lack of NEC compliance will be evident.
Why does the NEC have so many definitions related to service installations? In a recent class to keep up my CEUs, the instructor lost me completely with respect to all of these definitions. My top concern is there are too many types of service conductors. I felt comfortable before that class, but now I am unsure which definition applies on any given installation. Can you help?
I understand your frustration. There are many possible configurations for any service installation. For that reason, Article 100 has 11 definitions that apply to services. These definitions are critical to the proper application of requirements in Article 230 and throughout the NEC where requirements impact services. These definitions are well written and necessary for the NEC user to apply all of the associated requirements. We cannot begin to read, understand or apply these definitions until we have a solid grasp on what the NEC covers (the document scope) and what it does not cover. The scope of the NEC is outlined in 90.2(A), Covered, and (B), Not Covered.
Once we understand where the NEC applies, we can look at the term “service,” which applies to all conductors and equipment that deliver electric energy from the serving utility to the wiring system. This means the source of supply must originate from an electric utility to be identified as a “service.” No other source of supply can be recognized as such.
For example, a building off the grid that is only supplied by a standby generator is supplied by an outside feeder, not service conductors. The next definition we must consider is service point, which is where the facilities of the serving utility and the premises wiring are connected. Premises wiring is also defined in Article 100.
The service point is where the utility installation ends and conductors owned and installed by other than the utility are supplied. Premises wiring, which includes all interior and exterior wiring from the service point to the last outlet in the building or structure supplied, is all-encompassing. Premises wiring includes all service, feeder and branch circuit conductors downstream of the service point. Let’s now look at the definitions for the types of service conductors. The first two service conductor types we will discuss are not covered by the NEC but are defined and referenced in the Code for clarity and usability. Service drop conductors are installed overhead by the utility from the source (for example, a utility-owned pole-mounted transformer) to the service point. Service lateral conductors are installed underground by the utility and terminate at the service point (e.g., in a meter enclosure or handhole).
The NEC covers the remaining types of service conductors. Overhead service conductors are installed where the utility-owned conductors (e.g., a service drop) are not taken to the building or structure supplied. For example, a utility may only install service drop conductors on two poles to a property that is some distance from the utility system. In this case, the owner may need to set three or four more poles to supply the building or structure. For this installation, the service point is at the last pole installed by the utility, and the conductors installed on the owner-installed poles to the building or structure are overhead service conductors.
These overhead service conductors will terminate at the building or structure to another wiring method, which is defined as overhead system service entrance conductors. This term also applies to conductors (e.g., Type SE cable) that are supplied by a service drop at a building or structure. Underground service conductors are installed where the utility supply is underground and the utility does not install service lateral conductors to the building or structure. In this case, underground service conductors are spliced (typically in a handhole or manhole) to the underground utility supply. Where the underground service conductors terminate in a splice to other wiring methods at the building or structure supplied (e.g., conductors in a wireway to supply multiple service disconnecting means), those conductors are defined as underground system service entrance conductors.
The last definition pertinent to this discussion is service equipment, which includes all of the necessary equipment such as switches, circuit breakers, fuses and enclosures, etc. Service equipment is intended to constitute the main control and cut off of the utility supply.
Are multipurpose rooms always considered assembly occupancies? On a recent project, the owner and electrical inspector required us to make modifications in several rooms for compliance with 518.4. These rooms were not permitted to have more than 90 persons under any circumstances per the local building code. However, an electrical inspector pointed out that NEC Section 518.2 states a “multipurpose room” is always an assembly occupancy. Is that true?
No, multipurpose rooms are not always considered assembly occupancies. See the scope of Article 518 in 518.1, which very clearly states this article covers all buildings or portions of buildings or structures designed or intended for the gathering of 100 or more persons. In 518.2(A), examples of assembly occupancies are provided. To properly apply this requirement, it must be within the scope of the article. If those occupancies are not intended for 100 or more persons, they are not assembly occupancies.
See 518.2(B), which addresses multiple occupancies. This requirement clarifies that Article 518 applies only to the portion of a building considered an assembly occupancy and rooms or spaces for assembly purposes by less than 100 persons are classified as part of the other occupancy and are not assembly occupancies.
Is it permitted to tap the busbar in a panelboard to supply adjacent electrical equipment? An engineer working for one of our clients has requested we tap the bus in an 800-ampere (A) panelboard to supply a second panelboard with limited load. The only holes in the bus are already used to secure circuit breakers. We would have to drill new holes to install lugs secured with two bolts per lug to prevent movement. The design meets the requirements for tap conductors in Section 240.21. However, I have concerns about violating the panelboard listing.
Panelboards are not listed to be field-modified with tap conductors installed on the bus unless there are existing ones in the bus that are marked with the word “tap.” Drilling new holes or using existing ones that are tapped for circuit breakers for a tap would violate the product listing and 110.3(B). Where such a modification is necessary, a field evaluation can be performed by a research and testing laboratory to determine the impact the modification has on the panelboard.