Exam Cheat Sheet · Quick Reference
Tennessee LLE Limited Licensed Electrician
Tennessee · Prov
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
40
Passing score
73%
Exam time
120 min
Administered by
Prov
Format
Reference materials allowed
Tennessee State Portion 40 questions
General Knowledge
4 Q · 10%
Ohm's Law formulas and calculations (voltage, current, resistance, power)Series, parallel, and combination circuit analysisNEC Article 100 definitions and terminologyNEC Article 110 general installation requirements (approval, equipment examination, working clearances)Voltage drop calculations for single-phase and three-phase circuitsElectrical formulas for amperes, horsepower, kilowatts, and kVA (DC and AC)OSHA 1926 Subpart K electrical safety requirements for construction sites (GFCI, lockout/tagging, grounding)Common electrical distribution systems and conductor identification
Installation Requirements
3 Q · 8%
Working space depth, width, and height requirements for electrical equipment (NEC Table 110.26(A)(1) and Table 110.34(A))Underground installation minimum cover requirements by wiring method and location (NEC Table 300.5)Protection of conductors and cables against physical damage (bored holes, notches, framing members, roof decking)Equipment approval, listing, labeling, and marking requirementsElectrical connections: terminals, splices, and conductor temperature limitationsGuarding of live parts and minimum clearance of live parts by voltageEnclosure type selection for indoor and outdoor environments (NEC Table 110.28)Supporting conductors in vertical raceways: spacing intervals by conductor size and material
Services, Feeders, and Branch Circuits
7 Q · 18%
Branch-circuit ratings, conductor sizing, and overcurrent protection requirementsGFCI and AFCI protection requirements by location and occupancy typeRequired receptacle and lighting outlet placement in dwelling and non-dwelling occupanciesService entrance conductor installation, wiring methods, and clearancesService disconnecting means requirements, ratings, and locationFeeder conductor sizing, overcurrent protection, and ground-fault protection of equipmentBranch-circuit, feeder, and service load calculations using demand factorsOutside branch circuits and feeders: clearances, disconnecting means, and wiring methods
Overcurrent Protection
2 Q · 5%
Standard ampere ratings for fuses and inverse time circuit breakersConductor overcurrent protection based on ampacity and wire size (small conductors)Location of overcurrent protective devices in circuit (feeder taps and transformer secondary conductors)Physical placement and accessibility requirements for overcurrent devicesCircuit breaker requirements (marking, operation, voltage ratings, and arc energy reduction)Fuse types and fuseholder requirements (plug fuses, Type S fuses, cartridge fuses)Short-circuit current calculation procedures including transformer multiplier and fault currentCurrent-limiting fuse let-through current and component protection
Grounding and Bonding
5 Q · 12%
Grounding electrode system types and installation requirements (NEC 250.52, 250.53)Sizing grounding electrode conductors for AC systems (Table 250.66)Sizing equipment grounding conductors (Table 250.122)Main bonding jumper and system bonding jumper requirements and sizing (Table 250.102(C)(1))Equipment grounding conductor types, identification, and installation methods (NEC 250.118, 250.119)Bonding of services, piping systems, and structural metal (NEC 250.92, 250.104)Grounding of separately derived AC systems (NEC 250.30)Identification and use of grounded conductors (Article 200)
Conductors and Cables
4 Q · 10%
Conductor ampacity tables and temperature ratings (60°C, 75°C, 90°C) for copper and aluminumAmpacity correction factors for ambient temperature and adjustment factors for more than three current-carrying conductorsConductor insulation types, designations, and permitted applications by location (dry, damp, wet)Conductors in parallel: minimum size, matching requirements, and installation rulesCable type uses permitted and uses not permitted (NM, MC, AC, SE, USE, UF, TC, MI, MV)Securing and supporting requirements for cable types (intervals, distances from boxes)Conductor markings, identification, and minimum size requirementsFlexible cords and fixture wires: types, ampacities, permitted and prohibited uses
Raceways and Boxes
5 Q · 12%
Conduit fill calculations and conductor count tables (EMT, RMC, IMC, FMC, LFMC, PVC, ENT)Raceway securing and support intervals by conduit typeBox fill calculations and volume requirements per conductorPull and junction box sizing for conductors 4 AWG and larger (straight, angle, and U pulls)Permitted and prohibited uses of raceway types by location and conditionConduit bending requirements (bend radius, maximum bends per run, bending methods and calculations)Cabinets, cutout boxes, and enclosure installation requirements (wire-bending space, deflection, damp/wet locations)Cable tray systems: types, fill requirements, grounding, and ampacity
Hazardous Locations and Special Occupancies
5 Q · 12%
Classification of hazardous locations: Class I, II, and III Divisions 1 and 2 (Article 500)Material groups for Class I locations (Groups A, B, C, D) and Class II locations (Groups E, F, G)Wiring methods and sealing requirements for Class I Division 1 and 2 locations (Article 501)Zone classification system for Class I Zone 0, 1, and 2 locations and protection techniques (Article 505)Zone 20, 21, and 22 locations for combustible dusts and ignitible fibers/flyings (Article 506)Intrinsically safe systems: installation, wiring separation, and equipment requirements (Article 504)Specific hazardous occupancies: commercial garages, aircraft hangars, motor fuel dispensing facilities, bulk storage plants, and spray application processes (Articles 511–516)Health care facility essential electrical systems: life safety branch, critical branch, and equipment branch requirements (Article 517)
Low Voltage Alarms, Signaling Systems, and Communications
2 Q · 5%
Fire alarm circuit classifications: non-power-limited (NPLFA) vs. power-limited (PLFA) requirementsClass 1, Class 2, and Class 3 circuit power source requirements and voltage/power limitationsCable type selection and installation by location: plenums, risers, and general-purpose spacesBonding and grounding of communications, CATV, and broadband system cables and protectorsPrimary and secondary protector requirements for communications and fire alarm circuitsSeparation requirements between low-voltage signal circuits and electric light/power conductorsOptical fiber cable types (conductive vs. nonconductive) and installation methodsNetwork-powered broadband communications system cable types and power classifications
Lighting, Signs, and General Use Equipment
3 Q · 8%
Luminaire installation requirements and location restrictions (Article 410)Receptacle types, ratings, and installation requirements (Article 406)Switch types, ratings, and installation requirements (Article 404)Panelboard and switchboard installation, overcurrent protection, and grounding (Article 408)Electric signs and outline lighting disconnects, grounding, and branch circuits (Article 600)Fixed electric space-heating equipment installation, disconnecting means, and overcurrent protection (Article 424)Air-conditioning and refrigerating equipment disconnecting means, branch-circuit protection, and conductor sizing (Article 440)Swimming pools, spas, and fountains — GFCI protection, bonding, and luminaire requirements (Article 680)
Key Distinctions
Class I and Class II locationsvsClass III locations
Class I locations are subdivided into material Groups A, B, C, D and Class II into Groups E, F, G, while Class III locations have no material group designations.
NEC 2017 Section 500.6Transformer secondaries considered protected by the primary OCPDvsTransformer secondaries NOT considered protected by the primary OCPD
Per 240.4(F), 2-wire single-phase and delta-delta 3-wire secondary conductors are permitted to be protected by the primary-side device, but single-phase (other than 2-wire) and multiphase (other than delta-delta, 3-wire) secondary conductors shall not be considered protected by it.
NEC 2017 Section 240.4(F)THHNvsWet-location conductor types (MTW, RHW, RHW-2, TW, THW, THW-2, THHW, THWN, THWN-2, XHHW, XHHW-2, ZW)
Per 310.10(C), the listed types are suitable for wet locations, while THHN is rated for dry and damp locations only.
NEC 2017 Section 310.10(C)Type MI cable with copper outer sheathvsType MI cable with steel outer sheath
Per 332.108, a copper sheath provides an adequate path to serve as the equipment grounding conductor, while with a steel sheath a separate equipment grounding conductor shall be provided.
NEC 2017 Section 332.108EMT (358.28(B))vsIMC (342.28) and RMC (344.28)
EMT shall not be threaded (exception: EMT with factory-threaded integral couplings complying with 358.100), whereas IMC and RMC threaded in the field require a standard cutting die with a taper of 1 in 16 (3/4 in. taper per foot).
NEC 2017 Section 358.28(B)Overhead span up to 50 ft (225.6(A)(1), 1000 V or less)vsOverhead span longer than 50 ft
Open individual conductors must be not smaller than 10 AWG copper for spans up to 50 ft, but not smaller than 8 AWG copper for longer spans unless supported by a messenger wire (e.g., a 60-ft, 240 V span needs 8 AWG copper).
NEC 2017 Section 225.6(A)Receptacle load at 180 VA (220.14(I))vsReceptacle load at 90 VA per receptacle
Each single or multiple receptacle on one yoke is calculated at not less than 180 volt-amperes, while a single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles is calculated at not less than 90 volt-amperes per receptacle.
NEC 2017 Section 220.14(I)3-wire feeders sharing a common neutral (215.4(A))vs4-wire or 5-wire feeders sharing a common neutral
Up to three sets of 3-wire feeders are permitted to use a common neutral, but only two sets of 4-wire or 5-wire feeders are permitted to do so.
NEC 2017 Section 215.4(A)Straight pull box sizing (314.28(A)(1))vsAngle pull box sizing (314.28(A)(2))
For straight pulls the box length shall not be less than 8 times the trade size of the largest raceway, while for angle pulls the distance to the opposite wall is 6 times the largest raceway plus the sum of the other raceways in the same row.
NEC 2017 Section 314.28Grounding electrode conductor sized from Table 250.66vsGrounding electrode conductor to a concrete-encased electrode (250.66(B))
Table 250.66 gives minimum GEC size by service-entrance conductor size (e.g., over 3/0 through 350 kcmil copper requires a minimum 2 AWG copper GEC), while the portion that is the sole connection to a concrete-encased electrode is not required to be larger than 4 AWG copper.
NEC 2017 Table 250.66Hermetic motor-compressor branch-circuit conductors (440.32)vsHermetic motor-compressor branch-circuit short-circuit/ground-fault OCPD (440.22(A))
Conductors require an ampacity of at least 125% of the rated-load current (a minimum), while the OCPD may be rated up to 175% of the RLA (a maximum), increased only if needed to carry starting current to not more than 225% of the RLA.
NEC 2017 Section 440.22(A), 440.32Switch symbol S₃vsSwitch symbols S₂, S₄, Sₑ, Sₖ
S₃ designates a three-way switch, while S₂ is a double-pole switch, S₄ a four-way switch, Sₑ an electrolier switch, and Sₖ a key-operated switch.
Ugly's Electrical References 2020, Page 125Key Terms
Authority Having Jurisdiction (AHJ) NEC 2017 Article 100 (Definitions)
Per NEC Article 100, an organization, office, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure.
Ampacity NEC 2017 Article 100 (Definition of Ampacity)
Per NEC Article 100, the maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
Approved (110.2) NEC 2017 Section 110.2
Conductors and equipment required or permitted by the Code are acceptable only if approved, meaning acceptable to the authority having jurisdiction — a broader concept than listed, labeled, or certified alone.
Restricted access (240.6(C)) NEC 2017 Section 240.6(C)
For an adjustable-trip circuit breaker to be rated at its adjusted current setting, access must be restricted by removable and sealable covers over the adjusting means, bolted equipment enclosure doors, or locked doors accessible only to qualified personnel (a posted warning label does not qualify).
System of coordination (240.12) NEC 2017 Section 240.12
Where an orderly shutdown is required to minimize hazards, a system of coordination based on (1) coordinated short-circuit protection and (2) overload indication based on monitoring systems or devices is permitted.
Multiwire branch circuit (210.4(C)) NEC 2017 Section 210.4(C)
A circuit that shall supply only line-to-neutral loads, with only two exceptions: where it supplies only one utilization equipment, or where all ungrounded conductors are opened simultaneously by the branch-circuit overcurrent device.
Neutral conductor use (200.4(A)) NEC 2017 Section 200.4(A)
Neutral conductors shall not be used for more than one branch circuit, more than one multiwire branch circuit, or more than one set of ungrounded feeder conductors unless specifically permitted elsewhere in the Code.
Main bonding jumper (250.28(D)) NEC 2017 Section 250.28(D)
For a grounded service, it shall not be smaller than the sizes shown in Table 250.102(C)(1), which is based on the size of the largest ungrounded service-entrance conductor.
Aluminum/copper-clad aluminum grounding electrode conductor (250.64(A)) NEC 2017 Section 250.64(A)
Not permitted where in direct contact with masonry or the earth, or where subject to corrosive conditions, because aluminum corrodes rapidly under these conditions.
Type FCC (Flat Conductor Cable) system NEC 2017 Section 324.10(B)(1)
An under-carpet system in which the voltage between ungrounded conductors shall not exceed 300 volts and between an ungrounded conductor and the grounded conductor shall not exceed 150 volts; it shall not be used in residential buildings (324.12(4)) but is permitted in damp locations (324.10(E)) and hospital administrative office areas (324.12(5)).
Type MI cable sheath (332.108) NEC 2017 Section 332.108
A copper outer sheath provides an adequate path to serve as the equipment grounding conductor; where the outer sheath is steel, a separate equipment grounding conductor shall be provided.
Expansion fitting for PVC conduit (352.44) NEC 2017 Section 352.44
Shall be provided to compensate for thermal expansion and contraction where the expected length change is 6 mm (¼ in.) or greater in a straight run between securely mounted items.
Means to prevent dust entering a dust-ignitionproof enclosure (502.15) NEC 2017 Section 502.15
One of four permitted means is a horizontal raceway not less than 3.05 m (10 ft) long between a dust-ignitionproof enclosure and one that is not dust-ignitionproof.
Class I location boundary in a commercial garage (511.3) NEC 2017 Section 511.3
A Class I location shall not extend beyond an unpierced wall, roof, or other solid partition that has no openings.
Working space Condition B (151–600 V to ground) OSHA 29 CFR 1926, Subpart K, §1926.403(i)(1)(i), Table K-1
Exposed live parts on one side and grounded parts on the other side, requiring a minimum clear working distance of 3½ feet (OSHA 1926.403(i)(1)(i), Table K-1).
Conductors in parallel (310.10(H)(1)) NEC 2017 Section 310.10(H)(1)
Aluminum, copper-clad aluminum, or copper conductors for each phase, polarity, neutral, or grounded circuit are permitted to be connected in parallel (electrically joined at both ends) only in sizes 1/0 AWG and larger.
Formulas to Know
Ohm's law (voltage and current)
E = I × R and I = E / R; e.g., 8 A × 15 Ω = 120 V; 240 V / 48 Ω = 5 APower and current from power
P = E × I and I = P / E; e.g., 120 V × 12.5 A = 1,500 W; 1,500 W / 120 V = 12.5 APower change with voltage on a fixed resistance
P = E² / R — power varies with the SQUARE of voltage; at half rated voltage power is (1/2)² = 1/4 of rating (e.g., 1,200 W at 240 V → 300 W at 120 V)Branch current in a series-parallel circuit
RT = R_series + R_parallel (R_parallel from 1/Rp = 1/R2 + 1/R3 + …); I_total = E / RT; V across parallel bank = I_total × R_parallel; branch current = V_parallel / R_branch (e.g., 32 V, 5 Ω + 3 Ω = 8 Ω → 4 A; 4 A × 3 Ω = 12 V; 12 V / 6 Ω = 2 A)Total ampacity of parallel conductor sets
Ampacity of one set × number of sets; e.g., 350 kcmil copper at 90°C column of Table 310.16 = 350 A, two sets = 700 AGrounded conductor size for parallel service/feeder sets
Add the kcmil of the parallel sets, then use Table 250.102(C)(1); e.g., 2 × 350 kcmil = 700 kcmil, which falls in 'over 600 through 1,100 kcmil' → 2/0 AWG copperPull/junction box minimum length — straight pull (314.28(A)(1))
Length shall not be less than 8 × trade size (metric designator) of the largest racewayPull/junction box minimum distance — angle pull (314.28(A)(2))
6 × largest raceway in the row + sum of the other raceways in the same row; e.g., 6 × 3½ + (1½ + 2) = 24-1/2 inHermetic motor-compressor branch circuit sizing (440.32 / 440.22(A))
Conductor ampacity ≥ 125% × RLA (30 A × 1.25 = 37.5 A); OCPD not more than 175% × RLA (30 A × 1.75 = 52.5 A, so a 50 A device in NEC 2017/2020 which have no next-higher-size exception; NEC 2023/2026 Exception No. 1 permits the next higher standard rating, 60 A). If that device cannot carry starting current, it may be increased to not more than 225% × RLA (67.5 A → 60 A).EMT bending marks (Ugly's)
90° stub-up: mark = stub height − take-up (18 − 5 = 13 in for ½" EMT). Offset: first mark = measured distance + shrink (42 + 1-7/8 = 43-7/8 in), second mark follows at the offset spacing (26 in). 3-point saddle: side marks = 2.5 × obstruction height each side of center (2.5 × 6 = 15 in), center bent 45° and sides 22-1/2°, shrink = 3/16 × height (3/16 × 6 = 1-1/8 in).