ISA Utility Specialist Ch. 5 Electrical Knowledge

What is a volt? a unit of electrical force Electrical resistance determines how much __________ is required to move electricity along a conductor and is measured in __________. energy; ohms A conductor carrying more than __________ volts would be considered a NERC line. 200,000 2 examples of protective equipment: circuit breakers lightning receptors An energized wire or conductor in a circuit is also known as a __________. phase True or False? Guy wires are intended to help support poles but may become unintentionally energized. true A __________ is similar to a fuse or cutout, but it resets after a predetermined time period. re-closer Minimum working distances for qualified line-clearance arborists are specified in the __________ safety standard. ANSI Z133 When installing underground conductors, __________ should be used in tree root protection zones. tunneling Distribution transformers typically __________ primary circuit voltage for the end user. reduce Amp: the measure of electrical current Service lines and secondary distribution lines usually carry voltage between __________-__________ volts. 120-240 When a tree contacts one electrical conductor, it may cause a __________-to-__________ fault. phase-ground fault The minimum approach distance for non-qualified line clearance personnel from energized conductors 50 kV and less: 10 feet The condition that allows electricity to flow from one object to another is called: potential What is a Watt? a measure of electrical power A phase-to-phase fault occurs when there is contact between: two or more energized conductors If the coating on a weatherproofed conductor falls off, the conductor will often __________. deteriorate Ohm's Law describes the relationship between: voltage, current, & resistance Formula for Ohm's Law: Volts = Amps x Resistance (V = I x R) Formula for power: Power = Volts x Current (P = V x I) A __________ is another name for a generating plant, and is the source of most power in the U.S. The most common sources for this power are __________ __________, __________ or __________ turbines, & __________ __________. powerhouse; fossil fuels, wind or water turbines, & nuclear reactors Tree-caused physical damage to conductors, electrical equipment, and/or supporting structures is an example of a __________ failure. mechanical The most common type of wire used today is an aluminum wire with a steel reinforced core. This wire is known as: ACSR (Aluminum Conductor Steel-core Reinforced) Voltage Ranges: Extra-high transmission lines: __________-__________ volts Transmission lines: __________-__________ volts Subtransmission lines: __________-__________ volts Distribution lines: __________-__________ volts 345,000-765,000 volts 115,000-230,000 volts 23,000-115,000 volts 2,400-23,000 volts The voltage between the feet of a person standing near an energized, grounded object: step-potential Soil removed during trenching should be stored where? on the side of the trench that is away from the tree Circuits that carry the highest voltage to other parts of the distribution network are called: primary circuits __________ lines come off of primary circuits, but don't extend directly to a customer's property. secondary A device that can store energy & is used to either boost voltage or provide power factor correction: capacitor