HI Electrician flashcards
HI Electrician · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Ohm's Law
- V = I × R. Voltage equals current times resistance. Used to find the third quantity when two are known in a DC or purely resistive circuit.
- Three-phase power formula
- P = √3 × V_line-to-line × I × power factor. Used for balanced three-phase loads; for single-phase, P = V × I × PF.
- Parallel resistance
- 1/R_total = 1/R1 + 1/R2 + … The total resistance is always less than the smallest branch resistance, and voltage is equal across branches.
- Voltage drop formula
- Single-phase: VD = 2 × K × I × L / cmil. Three-phase: VD = √3 × K × I × L / cmil. K for copper is about 12.9.
- Box fill counting
- Each current-carrying conductor counts once, each device yoke twice, each grounding conductor once, and each clamp or support once. Compare total to Table 314.16(B).
- Continuous load sizing
- Branch-circuit conductors and overcurrent devices must be sized at 125% of the continuous load plus 100% of the noncontinuous load per NEC 210.19(A).
- Receptacle spacing rule
- In dwelling units, no point along the floor line may be more than 6 ft from a receptacle, and any wall space 2 ft or wider requires a receptacle (NEC 210.52).
- GFCI requirement
- GFCI protection is required for 125V 15/20A receptacles in bathrooms, garages, outdoors, kitchens, laundry areas, and within 6 ft of sinks (NEC 210.8).
- AFCI requirement
- AFCI protection is required for 120V 15/20A branch circuits supplying outlets in dwelling unit bedrooms, living rooms, and similar areas (NEC 210.12).
- Working space depth
- Depth in front of electrical equipment is 3 ft for 0–150V to ground, 3.5 ft for 151–300V, and 4 ft for 301–600V (NEC 110.26).
- Standard overcurrent ratings
- Standard ampere ratings include 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1000, and 1200A (NEC 240.6).
- Service disconnect location
- The service disconnecting means must be installed at a readily accessible location nearest the point of entrance of service conductors and marked with its rating (NEC 230.70, 230.79).
- NM-B cable restrictions
- NM-B is permitted in dry, concealed, and exposed locations in dwellings but not in damp or wet locations, embedded in masonry, or as service-entrance cable (NEC 334.10, 334.12).
- EMT support spacing
- EMT must be supported within 3 ft of each box and every 10 ft thereafter. Running threads are not permitted for support (NEC 358.30).
- RMC support spacing
- Rigid metal conduit must be supported within 3 ft of each box and every 10 ft thereafter, and threaded couplings must be wrench-tight (NEC 344.30).
- PVC support spacing
- PVC Schedule 40 must be supported within 3 ft of each box and every 3 ft thereafter; expansion fittings are required where thermal expansion is expected (NEC 352.30, 352.44).
- Box support by raceway
- A box may be supported by a raceway if the raceway is supported within 18 in of the box (NEC 314.23).
- Conductor bending radius
- Exposed conductors must have a bending radius of at least 4 times the overall diameter for sizes 1/0 and smaller, and 5 times for larger sizes (NEC 300.34).
- Underground feeder cover
- UF cable requires 24 in minimum cover for 120/240V residential branch circuits, and 18 in where GFCI-protected and 120V or less (NEC 300.5).
- Motor branch conductor sizing
- Motor branch-circuit conductors must have an ampacity of at least 125% of the motor full-load current from NEC Tables 430.248–430.250 (NEC 430.22).
- Motor overload protection
- Overload protection is sized per NEC 430.32 and protects the motor from overheating; the branch-circuit short-circuit device protects the circuit conductors.
- Motor disconnecting means
- A disconnecting means must be within sight of the motor and controller, or capable of being locked open (NEC 430.102).
- Controller horsepower rating
- A controller must have a horsepower rating not less than the motor it controls (NEC 430.83).
- Motor control circuit protection
- Control circuits derived from the motor branch circuit are protected per NEC 430.72; control transformers require primary and secondary overcurrent protection.
- Hawaii licensing authority
- Hawaii electrical licensing is administered by the Department of Commerce and Consumer Affairs (DCCA) through the Professional and Vocational Licensing Division (PVL).
- HRS Chapter 448E
- Hawaii Revised Statutes Chapter 448E governs electricians and electrical contractors; it establishes license categories and the electrical examining board.
- HAR Title 16 Chapter 115
- Hawaii Administrative Rules Title 16, Chapter 115 contains the rules for electricians and electrical contractors, including application, examination, and renewal requirements.
- Hawaii license categories
- License categories include journey worker electrician, supervising electrician, and electrical contractor; each has distinct experience and examination requirements.
- Unlicensed work prohibition
- Unlicensed electrical work is prohibited except for work exempt by statute, such as certain minor repairs or work by the owner on a single-family residence occupied by the owner.
- Lockout/tagout
- De-energize, isolate, lock, tag, and verify absence of voltage before work on electrical equipment (OSHA 1910.147).
- Shock protection boundaries
- Approach boundaries depend on voltage; the limited approach boundary for 120V is 10 ft for unqualified persons and 3 ft 6 in for qualified persons.
- Equipment grounding conductor
- Sized from NEC Table 250.122 based on the overcurrent device rating; it must run with circuit conductors and bond to all metal enclosures.