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

Under 430.72(B)(2) Note 3 the branch-circuit short-circuit/ground-fault device shall not exceed 300 percent of the 60°C ampacity for conductors larger than 10 AWG leaving the enclosure, while Note 2's 400 percent figure applies only where the conductors stay within the enclosure.

The system bonding jumper is the connection between the grounded circuit conductor and the supply-side bonding jumper and/or equipment grounding conductor at a separately derived system; the same connection made at the service is called the main bonding jumper.

A technical power system isolates the equipment grounding conductor from the premises grounded and equipment grounding conductors except at a single grounded termination point, while an isolated power system uses an isolation transformer, a line isolation monitor, and ungrounded circuit conductors.

Type MV is solid dielectric insulated cable rated 2001 volts up to and including 35,000 volts nominal, whereas the 2001 to 25,000 volt range belongs to the separate definition of portable power feeder cable.

A functionally grounded system has a ground reference for operational purposes that is not solidly grounded (often through electronic means inside an inverter or charge controller), rather than being connected to ground without any resistor or impedance device.

On grounded circuits it is the voltage between the given conductor and the grounded point or conductor; on ungrounded circuits it is the greatest voltage between the given conductor and any other conductor of the circuit.

110.26(A)(4) requires an opening not smaller than 559 mm × 559 mm (22 in. × 22 in.) above a lay-in ceiling, while the 559 mm × 762 mm (22 in. × 30 in.) dimension in the same subsection applies to a crawl space opening.

110.72 requires not less than 750 mm (2 1/2 ft) clear work space where cables are on one side only and not less than 900 mm (3 ft) where cables are on both sides; the 600 mm (2 ft) figure applies only under the exception for enclosures containing optical fiber, power-limited fire alarm, or Class 2/Class 3 circuits.

Unless listed and marked otherwise, the first group uses conductor ampacity based on the 60°C (140°F) rating, while the second group uses the 75°C basis.

FMC qualifies only where circuit conductors are protected at 20 amperes or less (trade size not over 1 1/4 and combined flexible length not over 1.8 m/6 ft), whereas the 60-ampere limit applies only to certain trade sizes of LFMC.

Two entrances not less than 610 mm (24 in.) wide and 2.0 m (6 1/2 ft) high are required for equipment rated 1200 amperes or more and over 1.8 m (6 ft) wide; the 800-ampere figure belongs to the personnel door/panic hardware rule, not the two-entrance rule.

The operating conductor shall not be smaller than 14 AWG copper or equivalent, while the protective bonding conductor must be as large as the lead-in and not smaller than 10 AWG copper, bronze, or copper-clad steel.

Class 1 circuit equipment shall be grounded unless it operates at less than 50 volts, while power-limited Class 1, Class 2, Class 3, and fire alarm circuit equipment is grounded only if system grounding is required by Part II or Part VIII of Article 250.

Per 90.3, Chapter 8 covers communications systems and is not subject to the requirements of Chapters 1 through 7 except where those requirements are specifically referenced in Chapter 8.