Journeyman Electrician Practice Test Verified Solutions

Journeyman Electrician Practice Test Verified Solutions 1. Conductors that are marked with _____ on their insulation are NOT approved for use in wet locations. - Answer: THHN. - Conductors with THHN insulation are suitable for dry and damp locations only, while THWN, THHW, and THW insulation types are permitted for use in both dry and wet locations. 2. For a one-family dwelling with a demand load of 200 amperes supplied by a 120/240 volt, single phase electrical system, what is the MINIMUM size aluminum THW conductors needed for the service entrance? - Answer: 4/0 AWG. - Service-entrance conductors must have an ampacity of at least 83% of the service rating. Therefore, 200 amperes x 83% = 166 amperes. The use of 4/0 AWG THW aluminum conductors with an allowable ampacity of 180 amperes is appropriate. 3. For a 150 kVA, single-phase transformer with a secondary voltage of 120/240 at a multi-family dwelling, what is the full-load current rating in amperes? - Answer: 625 amperes. - The full-load current can be calculated using the formula: I = (150 kVA x 1000) / 240 volts = 15,000 / 240 = 625 amperes. 4. Which of the following circuit breaker ratings is NOT standard? - Answer: 75 amperes. - Circuit breakers with a rating of 75 amperes are not part of the standard ampere ratings for breakers. 5. What is the MINIMUM length of free conductor that must be left at each junction box for the purpose of splicing or making connections? - Answer: 6 inches. - This allows sufficient slack for making terminal connections or splices easily. 6. What is the minimum allowable size for overhead service-drop conductors? - Answer: 8 AWG copper. - Overhead service-drop conductors must not be smaller than 8 AWG copper or 6 AWG aluminum or copper-clad aluminum. 7. When using a galvanized eye-bolt as an attachment point for electrical service, what is the required minimum height above finished grade? - Answer: 10 feet. - This height ensures adequate clearance for conductors to prevent damage and accidental contact that could lead to shock hazards. 8. What is the reason for requiring electrical continuity in metallic conduits? - Answer: To establish an effective ground-fault path and facilitate the operation of the over-current protective device. 9. In dwelling units, at what maximum height should receptacle outlets for countertop surfaces be installed? - Answer: 20 inches. - Receptacle outlets must be located above the countertop or work surface, not exceeding 20 inches, to avoid using unsightly extension cords and ensure they don't interfere with cabinetry installation. 10. When conductors are installed in conduit or tubing that is _____ or less in length, the ampacity adjustment factors for more than three current-carrying conductors are not required. - Answer: 24 inches. - This rule applies to ensure that smaller conduit runs do not necessitate adjustment factors for ampacity. adjustment factors for more than three (3) current-carrying conductors in raceways shall not apply where the raceway is not more than 24 inches in length. Where more than 3 current-carrying conductors are installed in short lengths of conduit or tubing, the heating effect caused from the additional conductors is insignificant therefore, the allowable ampacity of the conductors is not greatly reduced. In compliance with the NEC, the total marked rating of a 120-volt, cord-and-plug-connected room air conditioner shall not exceed _____ of the rating of a branch circuit when lighting units, general-use receptacles, or other appliances are supplied from the branch circuit. ️50% the special provisions for room air conditioners which are (1) rated not over 250-volts ac, single-phase and (2) which are cord-and-attachment plug connected. In order to prevent overloading the branch circuit, as per Section 40.62(C), the total rating of the A/C unit shall not exceed 50% of the rating of a branch circuit where lighting units, general-use receptacles or appliances are also supplied. What shall not be located over the steps of a stairway? ️overcurrent devices "overcurrent devices shall not be located over steps of a stairway." This requirement address a serious safety issue. No one should be required to stand on different treads on a stairway to replace, repair, maintain, install, troubleshoot, or reset overcurrent devices in a panelboard or switchboard located in a stairway. Where a permanently installed outdoor swimming pool is located on residential or commercial properties, at least one (1) single-phase, 125-volt, 15- or 20-ampere receptacle shall be located not less than _____ from and not more than _____ from the inside wall of the swimming pool. ️6 feet - 20 feet apply to the installation of wiring methods and equipment in or adjacent to permanently installed swimming pools.