Chapter 7 Questions
Some local electric utilities have rules that allow service entrance conductors to run within the building up to a specified length to terminate at the disconnecting means
T or F, Some local electric utilities have rules that allow service entrance conductors to run within the building up to a specified length to terminate at the disconnecting means?
What is a Riser
A length of raceway that extends up in a utility pole and encloses the service entrance conductors in an underground service entrance.
What is a Service Mast
A piece of RMC or IMC that provides service conductor protection and the proper height requirements for service drops
What is a grounded conductor
A system or circuit conductor that is intentionally grounded
An Exception says that a supplemental electrode is not required if the single rod, pipe, or plate has a resistance to earth of 25 ohms or less.
An Exception says that a supplemental electrode is not required if the single rod, pipe, or plate has a resistance to earth of_______ohms or less. A. 10 B. 15 C.20 D.25
What is a Drip Loop
An intentional loop put in a service entrance conductors at the point where they extend from a weatherhead; the drip loop conducts rainwater to a lower point than the weatherhead, helping to ensure that no water will drip down the serivce entrance conductors and into the meter enclosure.
Both overhead and an underground service must be installed at a readily accessible location either outside of a building or structure, or, if inside, as near as possible to the point of entrance of the service conductors.
Both overhead and underground services must be installed at a readily accessible location ___________ A. Outside B. Inside C. Both
Grounding electrodes of pipe or conduit cannot be smaller than 3/4-inch in trade size and, if made of steel, must have their outer surface galvanized or otherwise metal-coated for corrosion protection.
Grounding electrodes of pipe or conduit cannot be smaller than _________ in trade size and, if made of steel, must have their outer surface galvanized or otherwise metal-coated for corrosion protection. A. 1/4th inch B. 1/2 inch C. 3/4th inch D. 1 inch
Many electric utility companies require higher vertical clearances for overhead service conductors than what the NEC has.
If the NEC requirements state vertical clearences for overhead service conductors have to be 12 feet and your local utility company states that they have to be 15 feet, which restriction do you abide too?
Rod electrodes must be at least 8 ft (2.44m) in length and must be made of the following materials.
Rod electrodes must be at least _______ in length and must be made of the following materials. A. 6 feet B. 8 feet C. 10 feet D. 12 feet
What is a Service Entrance Cable
Service entrance conductors made up in the form of a cable
Where large rocks or ledge is encountered and a rod or pip can not be driven straight down into the ground, the electrode must be either driven at not more than a 45-degree angle or buried in a 2 1/2 foot deep trench.
T or F, Where large rocks or ledge is encountered and a rod or pip can not be driven straight down into the ground, the electrode must be either driven at not more than a 45-degree angle or buried in a 2 1/2 foot deep trench.
What is a Service Head/Weather Head
The fitting that is placed on the service drop end of service entrance cable or service entrance raceway and is designed to minimize the amount of moisture that can enter the cable or raceway.
What is a Service Drop
The overhead conductors between the utility electric supply system and the service point
What is a Service Point
The point of connection between the wiring of the electric utility and the premises wiring
What is a Meter Enclosure
The weatherproof electrical enclosure that houses the kilowatt-hour meter; also called the "meter socket" or "meter trim"
When installing overhead service conductors above a residential roof, conductors must have a vertical clearance of at least 8 feet.
When installing overhead service conductors above a residential roof, conductors must have a vertical clearance of at least ___ feet. A. 8 feet B. 10 feet C. 6 feet D. 20 feet
When taking a local or state electrical licensing exam, make sure to answer the question based on the NEC and not with information based on the local electric utility requirements.
When taking a local or state electrical exam, do you answer questions based on the NEC or based on your local electrical utility requirements?
Where the enclosure or raceway is subject to physical damage, the conductors must be installed in rigid metal conduit, intermediate metal conduit, RTRC-XW, Schedule 80 rigid PVC conduit, or a method that provides equivalent protection
Where the enclosure or raceway is subject to physical damage, the conductors must be installed in rigid metal conduit, _______________________, RTRC-XW, Schedule 80 rigid PVC conduit, or a method that provides equivalent protection
What is a Transformer
a piece of electrical equipment used by the electric utility to step down the high voltage of the utility system to the 120/240 volts required for a residential electrical system