North Carolina Electrical Contractor - Elevator (SP-EL)

North Carolina Electrical Contractor – Elevator (SP-EL) | 5 questions, 12% of exam

Key Concepts

Fundamental principle — the earth is not a fault path. Per NEC 250.4(A)(5), "The earth shall not be considered as an effective ground-fault current path." The effective ground-fault current path must be a low-impedance circuit capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system to the electrical supply source. The same statement appears for ungrounded systems in 250.4(B)(4): "The earth shall not be considered as an effective fault-current path."

Elevator-specific grounding (NEC 2020). Per Section 620.81, metal raceways, Type MC cable, Type MI cable, or Type AC cable attached to elevator cars shall be bonded to metal parts of the car that are bonded to the equipment grounding conductor.

North Carolina Electrical Contractor – Elevator (SP-EL) · 4 questions (10% of exam)

Key Concepts

Circuit breakers (Art. 240, Part VII) - Breakers shall be trip free and capable of being closed and opened by manual operation; normal operation by other than manual means is permitted if manual means are also provided — 240.80. - Breakers shall clearly indicate open "off"/closed "on"; where handles operate vertically, "up" is "on" — 240.81. - Marking: ampere rating durable and visible after installation, permitted to be made visible by removing a trim or cover — 240.83(A); breakers rated 100 A or less and 1000 V or less have the ampere rating molded, stamped, etched or similarly marked into handles or escutcheon areas — 240.83(B). - Interrupting rating: every breaker having an interrupting rating other than 5000 amperes must show it on the breaker; not required on breakers used for supplementary protection — 240.83(C). - Breakers used as switches in 120-volt and 277-volt fluorescent lighting circuits shall be listed and marked SWD or HID — 240.83(D). - Reconditioning:…

Key Concepts

Conductor sizing and construction (Article 310) - Minimum size of conductors for voltage ratings up to and including 2000 volts: 14 AWG copper or 12 AWG aluminum or copper-clad aluminum, except as permitted elsewhere in the Code — 310.3(A). - Where installed in raceways, conductors 8 AWG and larger shall be stranded, unless specifically permitted or required elsewhere to be solid — 310.3(C). - Aluminum, copper-clad aluminum, or copper conductors may be connected in parallel only in sizes 1/0 AWG and larger — 310.10(G)(1).

Elevator conductors (Article 620, Part II) - Hoistway door interlock conductors from the hoistway riser: flame retardant, Type SF or equivalent, suitable for not less than 200°C (392°F) — 620.11(A)(1); or physically protected by an approved method meeting the same criteria — 620.11(A)(2). - Minimum sizes, other than conductors forming an integral part of control equipment — 620.12: - Traveling cables, lighting circuits: 14 AWG copper (20 AWG or larger permitted in parallel if ampacity is at least equivalent to 14 AWG copper) — 620.12(A)(1) - Traveling cables,…

North Carolina Electrical Contractor – Elevator (SP-EL) · 2 questions (5% of exam) · Subtopics: General information, Sizing requirements

Key Concepts

Scope (NEC 314.1). Article 314 covers boxes and conduit bodies used as outlet, device, junction, or pull boxes, plus handhole enclosures, and fittings used to join raceways and connect raceways/cables to boxes. Cast metal, sheet metal, nonmetallic, and other boxes such as FS, FD, and larger boxes are not classified as conduit bodies.

Round boxes (NEC 314.2). Round boxes shall not be used where conduits or connectors requiring the use of locknuts or bushings are to be connected to the side of the box.

Nonmetallic boxes (NEC 314.3). Permitted only with open wiring on insulators, concealed knob-and-tube, cabled wiring methods with entirely nonmetallic sheaths, flexible cords, and nonmetallic raceways. Exception No. 1: where internal bonding means are provided between all entries, nonmetallic boxes are permitted with metal raceways or metal-armored cables. Exception No. 2: integral bonding means with a provision for attaching an equipment bonding jumper inside the box, between all threaded entries…

Key Concepts

Branch-circuit and feeder ampacity - Conductors supplying a single motor in a continuous duty application shall have an ampacity of not less than 125 percent of the motor full-load current rating, as determined by 430.6(A)(1) — 430.22. - For dc motors on a rectified single-phase supply, where a single-phase, half-wave rectifier bridge is used, conductors between the rectifier field wiring output terminals and the motor shall have an ampacity not less than 190 percent of the motor full-load current rating — 430.22(A). - For a wye-start, delta-run motor, conductors between the controller and the motor shall be not less than 72 percent of the motor full-load current rating (Informational Note: individual conductors carry 58 percent; 58% × 1.25 = 72%) — 430.22(C). - Feeders supplying several motors: ampacity not less than 125 percent of the full-load current of the highest rated motor, plus the sum of the full-load current ratings of all other motors in the group, plus 100 percent of noncontinuous non-motor load and 125 percent of continuous non-motor load —…

North Carolina Electrical Contractor – Elevator (SP-EL) · 3 questions, 8% of exam Subtopics: branch circuits · conductor ampacity · overcurrent protective device sizing · low-voltage

Key Concepts

Branch-circuit ratings - For branch circuits other than individual branch circuits, the rating shall be 15, 20, 30, 40, and 50 amperes. Where conductors of higher ampacity are used for any reason, the ampere rating or setting of the specified overcurrent device determines the circuit rating — NEC 2020, 210.18. - Branch circuits larger than 50 amperes shall supply only nonlighting outlet loads — 210.23(D). (Exception in 210.18: multioutlet branch circuits greater than 50 A may supply nonlighting outlet loads on industrial premises where maintenance and supervision ensure only qualified persons service the equipment.) - 40- or 50-ampere branch circuits may supply cooking appliances fastened in place in any occupancy; in other than dwelling units they may also supply fixed lighting units with heavy-duty lampholders, infrared heating units, or other utilization equipment — 210.23(C). - Dwelling units: two or more 20-ampere small-appliance branch circuits for all…

Key Concepts

Code arrangement and enforceability (Article 90)

• The Code is divided into the introduction and nine chapters. Chapters 1, 2, 3, and 4 apply generally. Chapters 5, 6, and 7 apply to special occupancies, special equipment, or other special conditions and may supplement or modify the requirements in Chapters 1 through 7. Chapter 8 covers communications systems and is NOT subject to the requirements of Chapters 1 through 7 except where the requirements are specifically referenced in Chapter 8. Chapter 9 consists of tables applicable as referenced. (NEC 2020/2017, Section 90.3)
• Mandatory rules identify actions specifically required or prohibited and are characterized by the terms shall or shall not. (Section 90.5(A))
• Permissive rules identify actions allowed but not required, describing options or alternative methods, characterized by shall be permitted or shall not be required. (Section 90.5(B))
• Explanatory material, such as informational notes, is informational only and is not enforceable as requirements of the Code. Informative annexes are likewise not part of the enforceable requirements. (Sections 90.5(C) and 90.5(D)) -…

Key Concepts

Board structure and authority - Members of the Board serve staggered seven-year terms; each member serves until a successor is designated or appointed and duly qualified (G.S. 87-39(b)). - Composition: one member from the N.C. Department of Insurance designated by the Commissioner of Insurance, one representative of the N.C. Association of Electrical Contractors, and five members appointed by the Governor (electrical engineering faculty member, a chief electrical inspector, an unlimited-license contractor representing the Carolinas Electrical Contractors Association, and two public members) (G.S. 87-39(a)). - The N.C. codes and standards for elevators, dumbwaiters, escalators, moving walks and personnel hoists, administered by the N.C. Department of Labor and codified as 13 NCAC 15 .0200, are incorporated by reference, current edition and amendments (21 NCAC 18B .0102(b)).