C -10 PLANNING AND ESTIMATING

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A house is 72 feet by 32 feet and requires lighting circuits, how many circuits are necessary if 120-volt, 15-amp circuits are desired?

4 (correct)

6

15

120

If 1,600 watthours were consumed over a period of 8 hours, then how many kilowatts were used every hour?

200kW

1,600kW

12,800kW

0.2kW (correct)

An electric stove is rated at 4,000 watts and is connected to a 240-volt circuit. What is the resistance of the heating elements?

12 Ohms

14.4 Ohms (correct)

16.6 Ohms

57,600 Ohms

Your client’s office equipment is using 3.4 kilowatts per day. How much time will pass before your client will use 3.2 million watts of power?

2.5 years Signup and view all the answers

A three-phase 120-volt AC circuit is running a current of 15 amps. If the power factor is 80% then what is the power rating in watts?

2491.2 watts Signup and view all the answers

What is the allowable wattage that can be connected to a 240-volt, 30-amp, single-phase circuit feeding a residential electric heater?

5760 watts Signup and view all the answers

How should you install photovoltaic panels on a Spanish clay tile roof?

Re-engineer the roof due to the extra weight Signup and view all the answers

What size flexible cables are used for solar battery interconnections?

2/0 AWG or larger Signup and view all the answers

If an inverter is rated for 40A, what inverter circuit breaker you should be using?

50A Signup and view all the answers

Which of the following tools helps prevent an electrician from receiving an electric shock while installing or removing fuses?

Fuse puller Signup and view all the answers

Energy storage systems (ESS) will frequently use ________ batteries, mainly due to their significant advances in power density.

Lithium-ion Signup and view all the answers

How is resistance measured?

Ohms Signup and view all the answers

A single-phase 120-volt AC circuit is running a current of 15 amps. If the power factor is 80% then what is the power rating in watts?

1,440 watts Signup and view all the answers

When installing a solar panel array on a sheet metal roof, which of the following will aid in distributing any live loads and dead loads?

Adding bar joists Signup and view all the answers

The inverter requires a MINIMUM voltage input of 350 volts. How many 48-volt modules need to be connected in a series configuration to meet the MINIMUM voltage input?

8 modules Signup and view all the answers

In a residential setting, which of the following locations should you NOT install an energy storage system?

Closets, spaces opening directly into sleeping rooms or habitable spaces of dwelling units Signup and view all the answers

Aside from plot, architectural, and e-sheets, what portion of the plans are most important to look over thoroughly?

Mechanical Signup and view all the answers

An 80W incandescent lightbulb uses 80 watts every hour on a 120-volt circuit. If the Incandescent bulb is turned on for 9 hours, then how many watthours are consumed?

720Wh Signup and view all the answers

Which of the following tools does NOT belong in an electrician’s toolbox?

None of the above Signup and view all the answers

If an incandescent light bulb has a resistance of 60 Ohms and is running on a current of 3 amperes, what is the voltage necessary for this circuit?

180 volts Signup and view all the answers

What is the formula of Ohms Law?

E = I × R Signup and view all the answers

What size of the circuit breaker can be installed on a line with 7 outlets and 14 AWG wire?

15 Amps Signup and view all the answers

A contractor needs 13 receptacles that cost $3.56 each plus sales tax of 7.25%. The supplier states that for every 10 receptacles that are purchased, the contractor will get one free of charge. What is the total cost of the receptacles?

$45.82 Signup and view all the answers

What is a blocking diode used for in PV systems?

To prevent backfeed of current Signup and view all the answers

Which of the following tools is used to bend conduit without causing physical damage to sharp bends?

Hickey Signup and view all the answers

If you have to install a ground rod in rocky soil what is acceptable?

Lay ground rod horizontally 30" deep Signup and view all the answers

What is the equivalent of 1.36kWh?

1,360 watt-hours Signup and view all the answers

What tool measures the specific gravity (SP) of the electrolyte in a flooded battery?

Hydrometer Signup and view all the answers

What does CO/ALR represent and where is it typically found?

Copper/Aluminum rating that is commonly found in switches and receptacles Signup and view all the answers

Which of the following connects a ground wire to the grounding rod?

Grounding rod clamp Signup and view all the answers

If you are connecting a 12-v battery set, what PV system design would you consider for your modules?

12v modules Signup and view all the answers

An energy storage system (ESS) must have an enclosure:

That is noncombustible Signup and view all the answers

The inverter MAXIMUM input voltage is 450 volts. How many 48-volt modules need to be connected in a series configuration to stay under MAXIMUM voltage input?

9 modules Signup and view all the answers

How many kWh will be consumed by a 500w lightbulb running for 3 hours?

1.5 kWh Signup and view all the answers

Suppose that a house requires 3 ceiling fans upstairs and 3 ceiling fans downstairs. If each ceiling fan costs $49.97, what is the total cost for the materials?

$299.82 Signup and view all the answers

What is the minimum horizontal separation between two outlets located on the opposite sides of a fire-resistance-rated wall assembly?

24 inches Signup and view all the answers

What do you use to secure the service entrance wires to the main breaker inside of a panel?

Lug terminal Signup and view all the answers

If a set of blueprints requires the installation of outlet receptacles on a wall but the windows are floor to ceiling, how should the contractor proceed to meet code requirements?

Move them to the floor Signup and view all the answers

If you have 4 mounting brackets per photovoltaic panel, how many brackets will be necessary for 6 panels?

24 Signup and view all the answers

Fish tape is used to run ______ through walls and electrical conduit.

Wires Signup and view all the answers

If you are awarded a contract to pull 300 feet of fiber optics cable, what should you do to ensure a successful install?

Use a wire tension and stress meter device Signup and view all the answers

If you receive plans for a bid and notice a code compliance issue, who do you inform?

Company inquiring into bid Signup and view all the answers

A kitchen circuit feeds a total of 8 outlets, if the contractor uses 12 AWG wire, what size circuit breaker will he install?

20 Amps Signup and view all the answers

What is the typical operating frequency of alternating current?

60 Hz Signup and view all the answers

What’s the maximum amount of bends for a run of metal conduit?

360 deg Signup and view all the answers

Where do you place GFCI outlets in a kitchen?

Above the countertop Signup and view all the answers

Suppose that a house requires a total of 37 receptacles. You need to purchase 15 standard duplex, 9 GFCI, and 13 AFCI receptacles. Calculate the total cost of materials if the standard duplex receptacles cost $4.90 for a set of ten and each GFCI receptacle costs $1.28 and $1.18 for every AFCI receptacle.

$40 Signup and view all the answers

The school replaces three hundred 80-watt incandescent light bulbs with 20-watt LED light bulbs. How much would the school save each year if they would run it for 2000 hours at $0.15/kWh?

$5,400 Signup and view all the answers

Your AC circuit is connected to a 480-volt source and draws 8 amps. When you connect a wattmeter, it reads 1400 watts. What is the power factor?

0.36 Signup and view all the answers

Which of the following is the most important to consider when installing photovoltaic panels on the roof?

The slope of the roof Signup and view all the answers

A voltage drop of 12 is found on a 480-volt circuit. What percentage is the voltage drop?

2.5% Signup and view all the answers

A three-phase generator has a ____ phase difference of a three-phase alternating current.

120º Signup and view all the answers

An 80W incandescent lightbulb uses 80 watts every hour on a 120-volt circuit. If the Incandescent bulb is turned on for 9 hours, then 720Wh are consumed. If you replaced the incandescent bulb with a 10W LED bulb, you will be saving 70W every hour. If this LED bulb operates for 9 hours, then what is the net savings in watthours when compared to the incandescent bulb?

630Wh Signup and view all the answers

If you receive plans to bid on a residential ground-up that has no existing electrical service, what first must you do?

Contact the local electrical utility regarding service availability Signup and view all the answers

If 3,400,000 watthours were consumed over a period of 2 days, then how many kilowatts were used every hour?

70.83kW Signup and view all the answers

Which of the following tools is used in the process of pulling wire?

Fish tape Signup and view all the answers

Which wire can you use in both wet locations and where exposed to high temperatures (90°C)?

THWN-2 Signup and view all the answers

Which of the following tools is used to manipulate wire by grabbing it, bending it and even cutting it?

Lineman's pliers Signup and view all the answers

Your AC circuit is connected to a 120-volt source and draws 10 amps. When you connect a wattmeter, it reads 1200 watts. What is the power factor?

100% Signup and view all the answers

Which of the following is a Fire Code requirement for vented batteries or other electrochemical energy storage systems?

Use flame-arresting safety caps Signup and view all the answers

A circuit has 22 LED bulbs and each bulb runs a current of 2.5 amps. If 12 volts flows through each bulb, then how many volts are running in the entire circuit?

12 volts Signup and view all the answers

The energy used by a city office is 2.9kW over a period of 8 hours. How many kW were consumed each hour?

0.36 kW Signup and view all the answers

Which of the following materials is used to fasten conduit to walls or other surfaces?

Conduit straps Signup and view all the answers

What is the maximum distance that outlets must be spaced for kitchen countertops?

4 feet Signup and view all the answers

Which type of current is better for carrying current over a large distance?

AC Signup and view all the answers

Of the methods provided, which is the best method used for connecting two pieces of conduit together?

Compression or setscrew coupling Signup and view all the answers

On new residential construction, you run a 500-foot run of cable and there is a voltage drop of 17.2 volts. What is the percentage of voltage drop in this circuit if it's operating at 600 volts?

3% Signup and view all the answers

Motors that have 10 horsepower or more are typically:

Three-phase Signup and view all the answers

What does the newer 2022 California Electrical Code language clarify with regard to bathrooms?

Receptacles not serving the countertop can be 15- or 20-amp Signup and view all the answers