Concept explainers
State which ungrounded conductors should be disconnected by the high-temperature limit control as per NEC 422.47 and provide the maximum water temperature that is limited by the high-temperature control.
Answer to Problem 1R
The high-temperature limit control should disconnect all the ungrounded conductors and the maximum water temperature limits to
Explanation of Solution
Discussion:
According to National Electric code NEC 422.47, the high-temperature limit control must disconnect all the ungrounded conductors.
Electric water heaters, which are utilized in residential, are listed under UL safety Standard 174, “Household Electric Storage Tank Water Heaters”.
The NEC and UL standard suggest that the electric water heater should be equipped with high temperature cut-off for safety purpose. The high-temperature control limits the water temperature into the maximum limit of
Conclusion:
Thus, the high-temperature limit control should disconnect all the ungrounded conductors and the maximum water temperature limits to
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Chapter 19 Solutions
EBK ELECTRICAL WIRING RESIDENTIAL
- A(n) _________ is a reliable conductor used to ensure the required electrical conductivity between metal parts required to be electrically connected. a) Equipment bonding jumper b) Bonding conductor of jumper c) Main bonding jumper d) Equipment grounding conductorarrow_forwardQUESTION 3 We are running 3 wires and a ground in a RMC to a control panel with a 60 amp circuit breaker disconnect in the control panel. The conduit is run along the ceiling where the ambient air temperature is 100 degrees. The control panel feeds our secondary cooling pump. What size are the ungrounded conductors? All conductors have typeTHHN insulation.arrow_forward7.A. Ferrous metal raceways or enclosures are made with _______ content.A. steel or brassB. aluminum or ironC. brass or aluminumD. iron or steel7.B. The size of a grounding electrode conductor for a service or separately derived system is generally basedon the size of the largestA. ungrounded supply conductor.B. equipment grounding conductor.C. grounded electrode.D. bonding jumper.7.C. Which of the following statements about bonding is true?A. The joint or termination must offer opposition in the circuit for effective electrical connections.B. Effective bonding keeps impedance high if a fault should occur.C. The entire electrical safety circuit is only as good as its strongest bonded link.D. Bonding connections must endure high levels of fault current until overcurrent protective devices can operate.arrow_forward
- 8.a. A _______ conductor does not carry current during normal operation.A. neutralB. groundingC. phaseD. grounded8.b. "The complete path of an electric current" describes an electric(al)A. fault.B. circuit.C. source.D. component.arrow_forwardA? Conductor is defined in NEC 240.2 as a conductor, other than a service conductor, having overcurrent protection ahead of its point of supply that exceeds the value permitted for similar conductors that are not taps. A. Faulted b. Tap c. Magnetic d. Copper-likearrow_forward14. A grounded circuit conductor and the equipment grounding conductor should always be joined at theservice by aA. steel raceway.B. main bonding jumper.C. bus bar.D. short length of aluminum conductor.arrow_forward
- The ohms per 1000 feet measurements for conductors can be found in _____. Select one: a. article 100 definitions b. 310.15(B)(16) c. annex C d. chapter 9 Table 8arrow_forward6. Which of the following statements about bonding is true?A. The strike terminals of a lightning protection system must be bonded to the building or structure grounding electrode system.B. Bonding requirements on the supply side of the service disconnect are less restrictive.C. Wire-type supply-side bonding jumpers are usually short in length and installed from the service-entrance conductor to asingle raceway.D. Metal water piping systems have one set of rules in the National Electrical Code.arrow_forward- Loads, Service, and Overcurrent Protection 6.a. The general lighting load is based on a _______ per square foot basis.A. kilowattB. number of circuitsC. volt-ampereD. general illumination6.b. What's the primary disadvantage of using copper conductors?A. AvailabilityB. WeightC. CostD. Durabilityarrow_forward
- of p o How many conductors enter the ceiling fan/light wall box? Switch ond out let boxes s tirst 10. What type and size of box may be used for the ceiling fan/light wall box?. 11. What type of covers are used with 4 in. square outlet boxes? 12. a. Does the circuit for the Master Bedroom have a grounded circuit conductor? b. Does it have an equipment grounding conductor? c. Explain the difference between a "grounded" conductor and an "equipment grounding" conductor. 13. Approximately how many feet (meters) of 2-wire cable and 3-wire cable are needed to ft complete the circuit supplying the Master Bedroom? Two-wire cable: ft (- m). m). Three-wire cable: 14. If the cable is laid in notches in the corner studs, what protection for the cable must be provided? 15. How high are the receptacles mounted above the finished floor in this bedroom? 16. Approximately how far from the bedroom door is the first receptacle mounted? (See the plans.) 17. What is the distance from the finished floor to…arrow_forwardH2. A/An _______ is an insulating tube or sleeve that protects an electrical conductor where it passesthrough a hole.A. expansion fittingB. couplingC. gland nutD. bushing H3. Conductors that are larger than AWG size 8 will come only as a/an _______ conductor.A. aluminumEnd of examB. coveredC. solidD. strandedarrow_forward11. Specific rules apply for the installation of _______, but no identification requirements for them exists.A. grounding electrode conductorsB. grounding electrodes.C. main bonding jumpers.D. equipment grounding conductors.arrow_forward
- EBK ELECTRICAL WIRING RESIDENTIALElectrical EngineeringISBN:9781337516549Author:SimmonsPublisher:CENGAGE LEARNING - CONSIGNMENT