Wyoming Low-voltage General Technician Exam (ICC 218, 2023 NEC)

(2023 NEC)

Key Concepts

Code structure (Article 90) - Chapter 8 covers communications systems and is not subject to Chapters 1–7 except where specifically referenced in Chapter 8 — 90.3.

Article 100 definitions (heavily tested) - Accessible, Readily: reachable quickly without tools other than keys, climbing over/under, removing obstacles, or portable ladders. Using a key still leaves equipment readily accessible. - In Sight From: visible and not more than 15 m (50 ft) distant — both conditions required. - Continuous Load: maximum current expected to continue 3 hours or more. - Low-Voltage Contact Limit: 15 V RMS sinusoidal ac; 21.2 V peak nonsinusoidal ac; 30 V continuous dc; 12.4 V peak dc interrupted at 10–200 Hz. - Cable Bundle: cables tied/contacting in a closely packed configuration for at least 1.0 m (40 in.). - Class 4 Circuit: also called a fault-managed power (FMP) circuit. - Voltage, Low (Article 551, RVs): 24 volts, nominal, or less. - Point of Entrance: where the wire/cable emerges from an external wall, roof, or concrete floor slab — not at the protector. - GFCI: Class A trips at 6 mA or higher, does not trip below 4 mA. - SPGFCI: used in circuits with voltage to ground greater than 150 volts (Class C, D, or E values). - GFPE: opens all ungrounded conductors of the faulted circuit. - Simple Apparatus: generates no more than 1.5 V, 100 mA, and 25 mW, or passive and dissipating no more than 1.3 W. - Type PLTC: two or more insulated conductors rated 300 volts under a nonmetallic jacket. Type MV: 2001 V through 35,000 V. Type IGS: 0 through 600 volts. - LFNC-C: corrugated internal and external…

Key Concepts

Class 1 circuits (Article 724) - Class 1 circuits shall be supplied from a source with a rated output of not more than 30 volts and 1000 volt-amperes (724.40). - Power sources other than transformers: protected by overcurrent devices rated not more than 167 percent of the volt-ampere rating of the source divided by the rated voltage; VAmax limited to 2500 volt-amperes and the product of Imax and Vmax not to exceed 10,000 volt-amperes, determined with overcurrent protection bypassed (724.40(B)). - Overcurrent protection for conductors 14 AWG and larger is based on conductor ampacity without applying the ampacity adjustment and correction factors of 310.15; protection shall not exceed 7 amperes for 18 AWG and 10 amperes for 16 AWG (724.43). - Branch-circuit taps of Class 1 conductors 14 AWG and larger: branch-circuit device rating not more than 300 percent of the Class 1 conductor ampacity (724.45(C)). - Class 1 and power-supply circuits may share a cable, enclosure, or raceway without a barrier only where the equipment powered is functionally associated (724.48(B)(1)). In cable trays without a solid fixed barrier, all conductors must be in separate multiconductor Type AC, MC, MI, or TC cables insulated at 600 volts or greater (724.48(B)(4)). - Safety-control equipment: conductors in RMC, IMC, RNC, EMT, Type MI cable, or Type MC cable, or otherwise suitably protected from physical damage (724.31). - Ampacity adjustment factors of 310.15(C)(1) apply only if Class 1 conductors carry continuous loads in excess of 10 percent of each conductor's ampacity (724.51(A)).

Key Concepts

Support, spacing and separation (Art. 800). CI cable in free air is supported at intervals not exceeding 610 mm (24 in.), secured to a noncombustible building surface, with steel supports and fasteners — 800.24(B). Cable routing assemblies run horizontally are supported at intervals not exceeding 900 mm (3 ft) and at each end or joint unless listed for other intervals, and in no case more than 3 m (10 ft); vertical runs at intervals not exceeding 1.2 m (4 ft) — 800.110(C)(1) and (C)(2). Keep at least 1.8 m (6 ft) from lightning protection conductors where practicable — 800.53. Direct-buried communications, CATV-type coaxial and network-powered broadband cables are separated at least 300 mm (12 in.) from light/power, NPLFA or Class 1 conductors — 800.47(B).

Cable use and listing. Unlisted outside plant cable inside a building may not exceed 15 m (50 ft) from the point of entrance, must enter from outside and terminate in an enclosure or on a listed primary protector — 800.48. Plenum cables up to 1.22 m (4 ft) are permitted in ducts specifically fabricated for environmental air if directly associated with the air distribution system — 800.113(B)(1). Limited-use cable in other building locations is limited to a maximum of 3 m (10 ft) exposed length in nonconcealed spaces — 800.113(J)(1). Communications wires and cables have a voltage rating of not less than 300 volts and a temperature rating of not less than 60°C — 800.179. Overhead service drop over a roof sloped not less than 4 in. in 12 in. may be reduced to not less than 900 mm (3 ft); the general requirement is 2.5 m (8 ft) — 800.44(B) Exc. No.…

Wyoming Low-Voltage General Technician (ICC 218, 2023 NEC) — 7 questions, 14%

Key Concepts

Motor control circuit overcurrent protection (NEC 430.72) - A control circuit tapped from the load side of the motor branch-circuit short-circuit and ground-fault (SCGF) protective device is not a branch circuit and may be protected by a supplementary or branch-circuit OCPD. A control circuit other than such a tapped circuit must be protected per 724.43 (Class 1 circuit overcurrent protection) or the notes to Chapter 9, Table 11(A) and Table 11(B) — 430.72(A). - Exception No. 1 to 430.72(B): where opening of the control circuit would create a hazard (example: a fire pump motor control circuit), the conductors require only short-circuit and ground-fault protection and may be protected by the motor branch-circuit SCGF device. - 430.72(B)(2): where conductors are protected by the motor branch-circuit SCGF device, Column B applies to conductors within the enclosure; Column C applies where conductors extend beyond the motor control equipment enclosure. - Control circuit transformers: rated less than 50 VA, integral to the motor controller and located within the controller enclosure — may be protected by primary OCPDs, impedance-limiting means, or other inherent protective means (430.72(C)(3)). Where rated primary current is less than 2 amperes, an OCPD rated or set at not more than 500 percent of rated primary current is permitted in the primary circuit (430.72(C)(4)). - 430.9(C): screw-type pressure terminals on control circuit devices used with 14 AWG or smaller copper shall be tightened to a minimum of 0.8 N·m (7 lb-in.) unless identified for a different torque.

Wyoming Low-Voltage General Technician (ICC 218, 2023 NEC) — 2 questions (4%)

Key Concepts

Scope and cross-references - Where optical fiber cables are utilized for fire alarm circuits, the cables shall be installed in accordance with Article 770 (NEC 2023, 760.3(E)). - For optical fiber cables, 722.3(O) directs you to Part V of Article 770. - Optical fiber cables installed in compliance with 770.48 are not required to be listed (722.179, Exception).

Listing and marking - Optical fiber cables shall have a temperature rating of not less than 60°C (140°F); a rating exceeding 60°C must be marked on the cable jacket (770.179; see also 722.179(B)). - Type markings per Table 722.179(B): OFNP = nonconductive optical fiber plenum; OFCP = conductive plenum; OFNR = nonconductive riser; OFCR = conductive riser; OFN/OFC = general-purpose nonconductive/conductive; OFNG/OFCG = alternative general-purpose nonconductive/conductive.

Installation in buildings - Types OFNG, OFCG, OFN, and OFC are not permitted in vertical runs (770.113(D)(2)). However, 770.113(E) permits these types in metal raceways in a riser having firestops at each floor. - In ducts specifically fabricated for environmental air, up to 1.22 m (4 ft) of Types OFNP and OFCP is permitted where the cable is directly associated with the air distribution system; longer runs and other types (OFNR, OFCR, OFNG, OFCG, OFN, OFC) must be in raceways installed per 300.22(B) (770.113(B)(1)). - Nonconductive optical fiber cables are permitted in ducts used for dust, loose stock, or vapor removal (722.3(D), Exception).