Exam Cheat Sheet · Quick Reference
South Dakota Class B Electrician Exam (ICC 533, 2023 NEC)
South Dakota · Pearson Vue
Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
60
Passing score
70%
Exam time
180 min
Administered by
Pearson Vue
Format
Reference materials allowed
South Dakota State Portion 60 questions
General Knowledge and Plan Reading
7 Q · 12%
Electrical Theory and General Electrical Load CalculationsCode Definitions and TermsNEC Purpose, Scope, and Code ArrangementSeries, Parallel, and Combination Circuit AnalysisAC Circuit Properties: Impedance, Reactance, Inductance, and CapacitancePower Factor, Apparent Power (kVA), and Power Factor CorrectionDwelling Unit Load Calculations (Lighting, Small-Appliance, Laundry, Cooking, and Dryer Loads)Feeder and Service Load Calculations with Demand FactorsElectrical Symbols and Wiring DiagramsUnits of Measurement, Metric System, and Electrical Conversions
Services and Service Equipment
13 Q · 22%
Service Load CalculationsService Equipment & Service ConductorsSystem Grounding and BondingService Disconnect Requirements and RatingsOvercurrent Protection for ServicesGrounding Electrode System and Electrode TypesSurge Protection Requirements for ServicesService Conductor Installation Methods and ClearancesDemand Factors for Dwelling and Non-Dwelling Loads
Feeders
8 Q · 13%
Load CalculationsEquipment GroundingFeeder conductor ampacity and minimum sizing (NEC 215.2)Overcurrent protection for feeders (NEC 215.3)Feeder disconnecting means for separate buildings and structures (NEC 225.31–225.39)Neutral conductor sizing for feeders (NEC 215.2(B), 220.61)Common neutral conductors and parallel feeder installations (NEC 215.4)Surge-protective device requirements for feeders supplying dwelling units (NEC 215.18, 225.42)Conductor identification for feeders — grounded, ungrounded, and EGC (NEC 215.12)Outside feeder conductor clearances and installation requirements (NEC 225.18–225.19)
Branch Circuits and Conductors
15 Q · 25%
Branch Circuit CalculationsRequired Outlets & GFCI/AFCI ProtectionOvercurrent ProtectionEquipment GroundingConductorsVoltage Drop Calculations and Conductor SizingConductor Ampacity Tables and Temperature RatingsAmpacity Correction and Adjustment FactorsConductor Insulation Types and ApplicationsGrounded Conductor Identification and UseMultiwire Branch Circuit RequirementsBranch Circuit Voltage Limitations and Ratings
+1 more
Wiring Methods and Materials
8 Q · 13%
Raceway InstallationsBoxes and EnclosuresFlexible Cords and CablesCable Wiring Methods (NM, MC, SE, USE, UF) — Uses Permitted and ProhibitedProtection of Cables and Raceways Against Physical DamageConductor Fill and Conduit Sizing CalculationsUnderground Installation Requirements and Minimum Cover DepthsConduit Bending Techniques and CalculationsSecuring and Supporting Requirements for Cables and RacewaysCorrosion Protection for Raceways and EnclosuresWiring in Ducts, Plenums, and Special Locations
Equipment and Devices
5 Q · 8%
LuminairesReceptacles, Switches and Other DevicesAppliances and Other EquipmentLuminaire location requirements (wet, damp, closets, bathtub/shower zones)Recessed luminaire installation (Type IC, clearances, thermal protection)Lighting track installation and construction requirementsLow-voltage lighting system requirements and voltage limitationsSwitch ratings, types, and connection requirementsReceptacle installation requirements (grounding, tamper-resistant, weather-resistant, GFCI)NEMA receptacle configurations and attachment plug wiring diagramsAppliance disconnecting means and GFCI protection requirements
Special Occupancies, Equipment and Conditions
4 Q · 7%
Swimming Pools and Similar InstallationsLow Voltage Circuits, Alarm & Similar SystemsFire Alarm Circuit Types: Power-Limited (PLFA) vs. Non-Power-Limited (NPLFA)Fire Alarm Circuit Power Source Requirements and Branch Circuit ProtectionSeparation and Mixing Rules for Fire Alarm Conductors and Other Circuit TypesFire Alarm Cable Types, Listings, and Application Requirements (FPLP, FPLR, FPL, NPLFP, etc.)Class 2 and Class 3 Power-Limited Circuit Wiring Methods and Power Source RequirementsCommunications System Grounding, Bonding, and Primary Protector RequirementsCable Installation Methods by Location: Plenums, Risers, and General-Purpose Spaces
Key Distinctions
Series circuit currentvsParallel circuit current
In a series circuit the total current equals the current in any other part of the circuit (IT = I1 = I2 = I3), while in a parallel circuit the total current equals the sum of the branch currents.
Ugly's Electrical References, 2023 ed., Series Circuits, Page 3 (2020 ed.: Series Circuits)Copper conductor K factor (12.9)vsAluminum conductor K factor (21.2)
Aluminum has roughly 1.6 times the resistance of copper, so its K value in the voltage-drop formula is 21.2 versus 12.9 for copper.
Direct-buried cables/conductors — minimum covervsRigid metal conduit or intermediate metal conduit — minimum cover
In all locations not specified elsewhere in Table 300.5(A), direct-buried cables need 600 mm (24 in.) of cover while RMC or IMC needs only 150 mm (6 in.).
NEC 2023 Table 300.5(A)One- and two-family dwelling driveway/outdoor parking (dwelling-related use only)vsAll locations not specified in Table 300.5(A)
A dwelling driveway is a specified location requiring 450 mm (18 in.) cover for both direct-burial cable and RMC, whereas the 150 mm (6 in.) RMC figure applies only to 'all locations not specified'; under general streets, highways, roads, alleys, driveways and parking lots the requirement is 600 mm (24 in.) for all wiring methods.
NEC 2023 Table 300.5(A)Straight pulls in pull boxes (conductors 4 AWG or larger)vsAngle or U pulls in pull boxes (conductors 4 AWG or larger)
Straight pulls require box length of not less than eight times the trade size of the largest raceway, while for angle or U pulls the distance from each raceway entry to the opposite wall shall not be less than six times the trade size of the largest raceway in a row.
NEC 2023 Section 314.28(A)(1)14 AWG box-fill volume allowancevs12 AWG box-fill volume allowance
Each 14 AWG conductor requires 32.8 cm³ (2.00 in.³) while each 12 AWG conductor requires 36.9 cm³ (2.25 in.³).
NEC 2023 Table 314.16(B)(1)Standard ampere ratings for fusesvsStandard ampere ratings for inverse time circuit breakers
Table 240.6(A) ratings apply to both, but 1, 3, 6, and 601 amperes are additional standard ratings for fuses only.
NEC 2023 Section 240.6(A) and Table 240.6(A)Overhead service conductor minimum size — coppervsOverhead service conductor minimum size — aluminum/copper-clad aluminum
Overhead service conductors shall not be smaller than 8 AWG copper or 6 AWG aluminum or copper-clad aluminum.
NEC 2023 Section 230.23(B)Ungrounded conductors in a 120/240-volt, single-phase, three-wire systemvsGrounded neutral conductor in a 120/240-volt, single-phase, three-wire system
Line one ungrounded is black and line two ungrounded is red, while the grounded neutral is white or gray.
Ugly's Electrical References, 2023 ed., Common Electrical Distribution Systems, Page 13 (2020 ed.: Common Electrical Distribution Systems)Installations covered by the NECvsInstallations not covered by the NEC
Per Article 90.2, the Code does not cover ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles — but it does cover mobile homes and recreational vehicles.
NEC 2023 Section 90.2(D)Protection where cables/raceways pass through bored holes or run parallel to framing membersvsProtection where cables/raceways are laid in notches in wood members
Bored holes and parallel runs must keep the cable/raceway not less than 32 mm (1 1/4 in.) from the edge of the wood/framing member, while cables or raceways in notches must be covered by a steel plate at least 1.6 mm (1/16 in.) thick of appropriate length and width.
NEC 2023 Section 300.4(A)(1)Switch symbol S₃vsSwitch symbol S₄
On electrical plans S₃ designates a three-way switch and S₄ designates a four-way switch (S₂ is double-pole, Sₑ is an electrolier switch).
Ugly's Electrical References 2020, Page 125Key Terms
Authority Having Jurisdiction (AHJ) NEC 2023 Section 90.4(B)
Per NEC 90.4, the authority having jurisdiction for enforcement has the responsibility for making interpretations of the rules, deciding on approval of equipment and materials, and granting special permission contemplated in the rules.
NEC organization (90.3) NEC 2023 Section 90.3
The Code is divided into an introduction and nine chapters: Chapters 1-4 apply generally, Chapters 5-7 apply to special conditions, Chapter 8 covers communications, and Chapter 9 consists of tables.
Service disconnecting means rating, one-family dwelling NEC 2023 Section 230.79(C)
Per NEC 230.79(C), the service disconnecting means for a one-family dwelling shall have a rating of not less than 100 amperes, 3-wire.
Optional dwelling-unit load calculation (220.82(A)) NEC 2023 Section 220.82(A)
The optional calculation applies to a dwelling unit whose total connected load is served by a single 120/240-volt or 208Y/120-volt set of 3-wire service or feeder conductors with an ampacity of 100 or greater.
Overhead service conductor clearance over public streets and alleys NEC 2023 Section 230.24(B)
Per NEC 230.24(B), overhead service conductors not in excess of 1000 volts nominal shall have a minimum clearance of 5.5 m (18 ft) over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other than residential property, and land such as cultivated, grazing, forest and orchard.
Vegetation as support NEC 2023 Section 230.10
Per NEC 230.10 and 225.26, vegetation such as trees shall not be used for support of overhead service conductors, service equipment, or overhead conductor spans for outside branch circuits and feeders — an absolute prohibition regardless of tree strength or conductor insulation.
Service-entrance cable support NEC 2023 Section 230.51(A)
Per NEC 230.51(A), service-entrance cables shall be supported by straps or other approved means within 300 mm (12 in.) of every service head, gooseneck, or connection to a raceway or enclosure.
Individual open service conductors near grade NEC 2023 Section 230.50(B)(2)
Per NEC 230.50(B)(2), individual open conductors and cables other than service-entrance cables shall not be installed within 3.0 m (10 ft) of grade level or where exposed to physical damage.
Free conductor length at boxes (300.14) NEC 2023 Section 300.14
At least 150 mm (6 in.) of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or connection of luminaires or devices.
Stranded conductors in raceways (310.3(C)) NEC 2023 Section 310.3(C)
Where installed in raceways, conductors 8 AWG and larger shall be stranded unless specifically permitted or required elsewhere in the Code to be solid.
Parallel conductors (310.10(G)(1)) NEC 2023 Section 310.10(G)(1)
Aluminum, copper-clad aluminum, or copper circuit conductors for each ungrounded, grounded, or neutral conductor shall be permitted to be connected in parallel only in sizes 1/0 AWG and larger.
Type THHN Conductor insulation type letters (THHN)
A conductor insulation whose letters mean T = thermoplastic, HH = high heat resistance (90°C dry), N = nylon outer jacket adding abrasion and gasoline/oil resistance; its maximum operating temperature is 90°C (194°F) in dry and damp locations.
Table 310.16 ampacity basis NEC 2023 Section 310.16
Ampacities in Table 310.16 are based on a 30°C (86°F) ambient temperature; for other ambients, correction factors from Table 310.15(B)(1)(1) must be applied.
Conductor size marking interval (310.8(B)(1)) NEC 2023 Section 310.8(B)(1)
The AWG size or circular mil area shall be repeated at intervals not exceeding 610 mm (24 in.) on single-conductor and multiconductor thermoset and thermoplastic-insulated wire and cable.
Vertical raceway conductor support (Table 300.19(A)) NEC 2023 Table 300.19(A)
Copper conductors 18 AWG through 8 AWG and 6 AWG through 1/0 AWG in vertical raceways shall be supported at intervals not greater than 30 m (100 ft), with support at the top of the vertical raceway and at intermediate points.
Raceway-supported enclosure limit (314.23(E)) NEC 2023 Section 314.23(E)
An enclosure that contains no device other than splicing devices and supports no luminaire, lampholder, or other equipment, and is supported by entering raceways, shall not exceed 1650 cm³ (100 in.³) in size.
Field-installed drainage openings (314.15) NEC 2023 Section 314.15
Approved drainage openings not smaller than 3 mm (1/8 in.) and not larger than 6 mm (1/4 in.) in diameter are permitted to be installed in the field in boxes or conduit bodies listed for damp or wet locations.
Nonmetallic-sheathed cable sheath entry (314.17(B)(2)) NEC 2023 Section 314.17(B)(2)
Where cable assemblies with nonmetallic sheaths are used, the sheath shall extend not less than 6 mm (1/4 in.) inside the box and 6 mm (1/4 in.) beyond the end of any cable clamp.
Device (yoke/strap) box-fill allowance (314.16(B)(4)) NEC 2023 Section 314.16(B)(4)
Each yoke or strap containing one or more devices or equipment requires a double volume allowance per Table 314.16(B)(1), based on the largest conductor connected to a device or equipment supported by that yoke or strap.
Main/system bonding jumper screw identification (250.28(B)) NEC 2023 Section 250.28(B)
If a main bonding jumper or system bonding jumper is a screw only, the screw shall be identified with a green finish that is visible with the screw installed.
Supplemental rod, pipe, or plate electrode spacing (250.53(A)(3)) NEC 2023 Section 250.53(A)(3)
Where multiple rod, pipe, or plate electrodes are installed to meet the requirements of this section, they shall not be less than 1.8 m (6 ft) apart.
Dwelling hallway lighting outlet (210.70(A)(2)) NEC 2023 Section 210.70(A)(2)
At least one lighting outlet controlled by a listed wall-mounted control device shall be installed in hallways of dwelling units (and per 210.52(H), hallways 10 ft or more in length require at least one receptacle outlet).
DPDT Ugly's Electrical References 2020, Page 126
A drawing abbreviation for Double Pole Double Throw, a switching contact controlling two separate circuits, each with two positions.
kVA Metric prefixes (kilo = 1,000)
Kilovolt-ampere; since kilo means 1,000, one kVA equals 1,000 volt-amperes, the common rating unit for transformers and services.
Formulas to Know
Ohm's Law and power formulas
I = W ÷ E (1500 W ÷ 120 V = 12.5 A); R = E ÷ I (240 V ÷ 8 A = 30 Ω); E = I × R (10 A × 12 Ω = 120 V); P = E × I; P = E² ÷ R (240² ÷ 20 = 2880 W); R may also be found as E² ÷ P (14,400 ÷ 1200 W = 12 Ω)Minimum feeder / service-entrance conductor ampacity with continuous loads
Ampacity ≥ noncontinuous load + 125% of continuous load (feeder: 100 A cont. × 125% + 30 A noncont. = 155 A; 60 A cont. × 1.25 + 40 A noncont. = 115 A where the OCPD/assembly is not listed for 100% rating)Minimum pull box dimensions, conductors 4 AWG or larger
Straight pulls: box length ≥ 8 × trade size of largest raceway (3 in. raceway → 8 × 3 = 24 in. / 610 mm). Angle or U pulls/splices: distance from each raceway entry to opposite wall ≥ 6 × trade size of the largest raceway in a row.Ampacity adjustment for more than three current-carrying conductors (Table 310.15(C)(1))
4-6 conductors = 80% of table ampacity; 7-9 conductors = 70%; 10-20 conductors = 50%Single-phase voltage drop
VD = (2 × K × I × L) ÷ CM, where the factor 2 accounts for the out-and-back length of both conductors; e.g., 120 V, 16 A, 60 ft, 12 AWG Cu (6,530 cmil), K = 12.9 → 24,768 ÷ 6,530 = 3.79 V (≈3.2%); 240 V, 30 A, 100 ft, 6 AWG Al (26,240 cmil), K = 21.2 → 127,200 ÷ 26,240 = 4.85 VMaximum one-way length for a given percent voltage drop
L = (VD × CM) ÷ (2 × K × I); e.g., 240 V × 0.03 = 7.2 V allowable, 8 AWG Cu (16,510 cmil), 40 A, K = 12.9 → 118,872 ÷ 1,032 = 115 ft one-wayMinimum conductor circular mils for a voltage-drop limit
CM = (2 × K × I × L) ÷ VD; e.g., 120 V × 0.03 = 3.6 V allowable, 20 A, 80 ft, K = 12.9 → 41,280 ÷ 3.6 = 11,466 cmil, so 8 AWG (16,510 cmil) is the smallest acceptable size even though ampacity alone would permit 12 AWGSeries-parallel resistance and branch current analysis
Equal parallel branches: Rp = R ÷ number of branches (three 18 Ω → 6 Ω). Two unequal branches: Rp = (R1 × R2) ÷ (R1 + R2). Series-add strings first, then combine in parallel, then add series resistors: RT = R1 + Rp. Then IT = E ÷ RT; voltage across the parallel bank = IT × Rp (or source E minus the series drop), and each branch current = bank voltage ÷ branch R.Total current in a parallel circuit
IT = sum of branch currents, each found as I = E ÷ R; e.g., 120 V across 10 Ω, 20 Ω, 20 Ω → 12 A + 6 A + 6 A = 24 ADwelling general load components (Article 220)
General lighting = floor area × 3 VA per sq ft; each small-appliance circuit = 1,500 VA; each laundry circuit = 1,500 VA; add for total (e.g., 2,000 sq ft → 6,000 + 2×1,500 + 1,500 = 10,500 VA; 1,800 sq ft with 3 small-appliance and 2 laundry circuits → 5,400 + 4,500 + 3,000 = 12,900 VA; four 1,200 sq ft units at 8,100 VA each = 32,400 VA before demand factors)Ampacity of parallel conductor sets
Total ampacity = table ampacity of one set × number of parallel sets; e.g., 350 kcmil copper at 90°C = 350 A, two sets → 700 AElevator feeder demand factors (Table 620.14)
Multiply elevator feeder load by the demand factor for the number of elevators: 1 = 1.00, 2 = 0.95, 3 = 0.90, 4 = 0.85, 5 = 0.82, 6 = 0.79, 7 = 0.77, 8 = 0.75, 9 = 0.73, 10 or more = 0.72; factors are based on a 50 percent duty cycle.