South Carolina Electrician Contractor Examination

A balanced 208-volt, three-phase lighting panel on a Charleston commercial job draws 48 amperes at a lagging power factor of 0.82. Using √3 = 1.732, what is the real power of this load?

• A17.3 kW
• B20.0 kW
• C8.2 kW
• D14.2 kW

A 120-volt, single-phase, 2-wire branch circuit supplies an 18-ampere load. The one-way conductor length is 85 feet of 12 AWG copper (K = 12.9, area = 6,530 CM). What is the calculated voltage drop?

• A3.02 volts
• B5.23 volts
• C6.05 volts
• D9.94 volts

A purely resistive 240-volt strip heater installed in a Columbia shop has a measured resistance of 20 ohms. What current does the heater draw, and what is its power?

• A8 A and 1,920 W
• B10 A and 2,400 W
• C12 A and 2,880 W
• D16 A and 3,840 W

A single-phase dry-type transformer serving a Greenville tenant space has a 480-volt primary and a 208-volt secondary. If the primary current is 45 amperes, what is the secondary current? Ignore losses.

• A19.5 A
• B45 A
• C90 A
• D104 A

What is the peak (zero-to-peak) value of a 208-volt RMS sinusoidal line-to-line voltage? Use √2 = 1.414.

• A147 V
• B187 V
• C208 V
• D294 V

A 120-volt, 60 Hz series circuit contains 8 ohms of resistance, 12 ohms of inductive reactance, and 6 ohms of capacitive reactance. What is the circuit current?

• A8.6 A
• B10.0 A
• C12.0 A
• D15.0 A

A three-phase motor load on a Rock Hill feeder measures 36 kW of real power and 48 kVA of apparent power. What is the power factor, and what is the reactive power?

• A0.75 lagging and 12.0 kVAR
• B1.33 leading and 31.7 kVAR
• C0.80 lagging and 27.0 kVAR
• D0.75 lagging and 31.7 kVAR

A 25-horsepower, 480-volt, three-phase motor is 88 percent efficient and operates at a 0.90 lagging power factor. Using 746 W/hp and √3 = 1.732, what line current does the motor draw?

• A34.0 A
• B49.1 A
• C24.9 A
• D28.3 A

A 480-volt, three-phase feeder carries 65 amperes for 220 feet on 2 AWG copper. Use K = 12.9, √3 = 1.732, and a circular-mil area of 66,360 CM. What is the calculated voltage drop?

• A4.82 volts
• B5.56 volts
• C7.91 volts
• D2.78 volts

Two 24-ohm resistors are connected in parallel, and that combination is in series with an 8-ohm resistor. The circuit is supplied at 120 volts. What current flows through each 24-ohm resistor?

• A3.0 A
• B5.0 A
• C6.0 A
• D2.0 A

On an inductive three-phase motor load, current lags voltage. Which statement correctly describes that condition?

• AThe power factor is unity and reactive power is zero.
• BThe power factor is leading because motors generate vars.
• CThe power factor is leading and reactive power is capacitive.
• DThe power factor is lagging and the load consumes vars.

A 3,200 sq ft one-family dwelling in Lexington County is calculated under the 2020 NEC standard method. Using 3 VA per square foot, two 1,500 VA small-appliance circuits, and one 1,500 VA laundry circuit, what is the general lighting, small-appliance, and laundry load after Table 220.42 demand factors?

• A6,885 VA
• B9,600 VA
• C14,100 VA
• D5,310 VA

A continuous 32-ampere load supplies showroom lighting in a Myrtle Beach storefront. What is the minimum branch-circuit overcurrent-device rating required by 210.20(A)?

• A32 A
• B35 A
• C40 A
• D50 A

For a one-family dwelling, which combination of 20-ampere branch circuits does the 2020 NEC require in addition to general lighting circuits?

• ATwo small-appliance circuits only
• BOne bathroom circuit and one outdoor circuit only
• COne small-appliance circuit and one laundry circuit only
• DTwo small-appliance circuits, one laundry circuit, one bathroom circuit, and a 20-ampere…

What is the minimum service-disconnect rating the 2020 NEC requires for a one-family dwelling?

• A100 A
• B150 A
• C200 A
• D60 A

A 200-ampere feeder supplies a single panelboard in a Sumter warehouse. The ungrounded conductors are 4/0 AWG aluminum THWN, which Table 310.16 lists at 180 A in the 75°C column. What is the largest standard overcurrent device 240.4(B) permits for these conductors?

• A150 A
• B175 A
• C180 A
• D200 A

A new 8,500 sq ft office suite in downtown Columbia is calculated under the 2020 NEC. Using Table 220.12, what is the minimum general lighting load?

• A17,000 VA
• B25,500 VA
• C29,750 VA
• D11,050 VA

A 400-ampere feeder in a Greenville plant is tapped using the 25-foot tap rule of 240.21(B)(2). What is the minimum ampacity of the copper tap conductors if they terminate in a single overcurrent device?

• A100 A
• B125 A
• C134 A
• D400 A

Under the 2020 NEC as adopted in South Carolina, which kitchen receptacles in a dwelling unit require GFCI protection?

• AAll receptacles installed in the kitchen
• BOnly the refrigerator receptacle
• COnly receptacles serving countertop surfaces
• DOnly receptacles within 6 feet of the sink

In a dwelling unit, which 120-volt, 15- or 20-ampere branch circuit does the 2020 NEC require to be AFCI-protected?

• AAn outdoor receptacle circuit only
• BA dedicated electric-range circuit
• CA bathroom receptacle circuit only
• DA bedroom, living-room, or similar habitable-room circuit

In a dwelling-unit habitable room, receptacles must be installed so that no point measured horizontally along the floor line of any wall space is more than which distance from a receptacle outlet?

• A6 feet
• B8 feet
• C12 feet
• D4 feet

The 2020 NEC added an outdoor emergency disconnect requirement for which occupancies?

• AOne- and two-family dwelling units
• BAny building with a fire pump
• CAll commercial buildings with a 400-ampere or larger service
• DHospitals and assembly occupancies only

A 400-ampere service in Spartanburg uses 350 kcmil copper ungrounded service conductors. What is the minimum copper grounding electrode conductor required by Table 250.66?

• A1/0 AWG
• B2/0 AWG
• C4 AWG
• D2 AWG

What is the minimum copper equipment grounding conductor for a 200-ampere feeder, based on Table 250.122?

• A4 AWG
• B3 AWG
• C8 AWG
• D6 AWG

A single ground rod is driven at a Hilton Head service. Unless the rod has a resistance to ground of 25 ohms or less, what does 250.53(A)(2) require?

• AA supplemental electrode must be added, and the two electrodes must be at least 6 feet ap…
• BThe grounding electrode conductor must be increased one size.
• CThe service must be ungrounded.
• DThe rod must be replaced with a concrete-encased electrode.

Which installation qualifies as a concrete-encased electrode under 250.52(A)(3)?

• A20 feet or more of 1/2-inch electrically conductive reinforcing bar, or 20 feet of 4 AWG…
• BAny rebar that happens to be in a slab, regardless of length
• CA single 8-foot ground rod set in the footing
• D10 feet of 6 AWG copper laid on the vapor barrier

Where is the grounded (neutral) conductor required to be bonded to the grounding electrode system at a grounded AC service?

• AOnly at the utility transformer
• BOnly at a separately derived system, never at the service
• CAt every downstream panelboard
• DAt the service disconnecting means, by a main bonding jumper or the equivalent connection…

A 480Y/277-volt, 75 kVA dry-type transformer in an Anderson mechanical room is a separately derived system. The secondary ungrounded conductors are 3/0 AWG copper. What table is used to size the system bonding jumper?

• ATable 250.122, based on the secondary breaker
• BTable 310.16, based on secondary ampacity
• CTable 250.102(C)(1) or Table 250.66, based on the derived ungrounded conductors
• DTable 430.250, based on the largest motor

A 100-ampere feeder uses 3 AWG copper ungrounded conductors (52,620 CM) and an 8 AWG copper equipment grounding conductor. The ungrounded conductors are increased to 1/0 AWG copper (105,600 CM) for voltage drop. What is the minimum copper EGC after 250.122(B)?

• A8 AWG
• B6 AWG
• C4 AWG
• D3 AWG

A metal underground water pipe is used as a grounding electrode. Which statement is correct under Article 250?

• AThe connection of the grounding electrode conductor to the water pipe must be made within…
• BThe pipe may be used only if it is plastic downstream of the meter.
• CNo bonding jumper is required around a water meter.
• DThe pipe alone is always a complete grounding electrode system.

Aluminum grounding electrode conductors are not permitted to be installed within how many inches of the earth?

• A6 inches
• B12 inches
• C18 inches
• D24 inches

A 400-ampere service uses 500 kcmil copper ungrounded conductors. What is the minimum copper supply-side bonding jumper between service enclosures, based on Table 250.102(C)(1)?

• A2 AWG
• B1/0 AWG
• C2/0 AWG
• D3 AWG

An intersystem bonding termination at a dwelling service is required so that which systems can be bonded to the building grounding electrode system?

• AOnly the swimming-pool bonding grid
• BOnly the lightning-protection down conductors
• COnly the interior water piping
• DCommunications, CATV, and similar intersystem bonding conductors

What is the Table 310.16 75°C ampacity of 3/0 AWG copper THWN, not more than three current-carrying conductors in a raceway?

• A225 A
• B230 A
• C175 A
• D200 A

Unless 240.4(E) or (G) applies, what is the maximum overcurrent protection 240.4(D) permits for a 12 AWG copper conductor?

• A15 A
• B20 A
• C25 A
• D30 A

A 4 AWG copper THWN conductor (75°C column ampacity 85 A) is installed in a rooftop raceway where the ambient temperature is 42°C. Using Table 310.15(B)(1), what is the corrected ampacity?

• A69.7 A
• B74.8 A
• C85.0 A
• D59.5 A

Eight current-carrying 8 AWG copper THHN conductors are installed in one EMT in a 30°C ambient. Starting from the 90°C ampacity of 55 A and applying Table 310.15(C)(1), what is the adjusted ampacity?

• A27.5 A
• B38.5 A
• C44.0 A
• D50.0 A

For circuits rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors, 110.14(C)(1) generally requires ampacity to be selected from which temperature column unless the equipment is listed and marked otherwise?

• A60°C
• B75°C
• C90°C
• D110°C

Where is Type NM cable not permitted?

• AConcealed in wood-frame walls of a one-family dwelling
• BIn a wet or damp location
• COn a 20-ampere dwelling lighting circuit
• DAs a 12 AWG home-run in a dry basement

Why may a contractor start an ampacity adjustment calculation in the 90°C column for THHN, even when the circuit breaker is marked 75°C?

• ABecause 310.15(A) and 110.14(C) allow the 90°C ampacity to be used for adjustment and cor…
• BBecause Table 310.16 does not include a 75°C column for THHN
• CBecause 240.4(D) replaces all temperature limits
• DBecause THHN terminations are always 90°C

When conductors are run in parallel, 310.10(G) requires each paralleled ungrounded conductor to be at least which size?

• A4 AWG
• B2 AWG
• C1 AWG
• D1/0 AWG

In which of the following installations is the grounded (neutral) conductor counted as a current-carrying conductor for ampacity adjustment?

• AA 120/240-volt, single-phase, 3-wire feeder that carries only unbalanced current on the n…
• BA 3-wire circuit consisting of two phase conductors and the neutral of a 4-wire, 3-phase,…
• CA dedicated 240-volt, 2-wire line-to-line water-heater circuit with no neutral
• DA 120/240-volt range circuit whose neutral carries only imbalance from a balanced 240-vol…

How must a grounded (neutral) conductor 6 AWG or smaller generally be identified?

• AGreen or green with yellow stripes
• BWhite or gray, or three continuous white or gray stripes on other than green insulation
• COrange
• DBare only