NHIE Home Inspector Manual Electrical System Study 2024-2025 Edition. Questions & Ans. A+, Exams of Electrical Engineering

Download NHIE Home Inspector Manual Electrical System Study 2024-2025 Edition. Questions & Ans. A+ and more Exams Electrical Engineering in PDF only on Docsity! NHIE Home Inspector Manual: Electrical System Study 2024-2025 Edition. Questions & Correct Answers. Graded A+ 1) What are 2 outdoor receptacle requirements? - ANSOutdoor receptacles: 1) At least one GFCI protected receptacle located within 78-in vertically from deck, balcony, or porch 2) Receptacle accessible from outside Are home inspectors required to test 3 & 4-way switches? - ANSYes, inspectors are required to test these switches from each switch and with different switch orientations. Are Inspectors required to inspect GFCIs? - ANSWhile they are not required to by SOP, many do using either a tester or a testing device. - WA State requires testing all GFCIs. armored cable -- Describe its period of use, description, application, EGC acceptability? - ANS- Period of use: From early 1900s to current - Description: insulate conductors in flexible interlocking metallic covering; may be smooth or corrugated, conductors wrapped in paper - Application: Dry locations not exposed to moisture - EGC acceptability: Yes, after 1959 Can & should home inspectors test alarms (e.g., fire or carbon monoxide)? - ANSHome inspectors: - Test fire & carbon monoxide detectors - Test w/caution - Button tests sound function - Button does not indicate alarm function properly Note: - Explain limitation in report Can exposed incandescent bulbs be located in clothes closet? - ANSNope Define knob and tube and when it was used. - ANSKnob and tube gets its name from the ceramic insulators used to support the conductors and from the ceramic tubes used to protect the conducted when they ran through the framing members. Knob and tube was used from the early 1900s to the 1930s. It is considered obsolete; however, it may be installed today as an extension of existing knob and tube with permission from the local building department. Define Service Equipment (e.g., main shut off) - ANSService equipment is the means to disconnect all electricity to the house. Service equipment may be circuit breakers, fuses, or switches. Important: - Disconnecting service equipment should not require operating or pulling no more than 6 circuit breakers, fuse blocks, and switches in any combination. - The service equipment should be labeled to indicate function. Do large appliance need disconnects? - ANSYes, large appliances (HVAC, AC, etc.) should have a means to disconnect electricity for safety and serviceability. The fuse or circuit beaker is acceptable if in sight of appliance; a separate disconnect should be installed if not. During what period where fuse-style OPDs installed in panelboards? - ANS- Commonplace from 1940s to late 1960s Note: - Usually panelboards using fuses are past service life Electrical metallic tubing -- Describe its period of use, description, application, EGC acceptability? - ANS- Period of use: N/A - Purpose: designed for routing and protesting conductors and cables - Construction: Usually made of PVC; ranges from 1/2 to 2 in diameter - Application: Used in most locations; except those exposed to physical damage; may not be barried; can be imbedded in concrete; support every 3 ft from boxes and terminations; protect w/nail gaurds - EGC acceptability: No Electrical non-metallic tubing (EMT, AKA "thin wall") -- Describe its period of use, description, application, EGC acceptability? - ANS- Period of use: N/A - Purpose: designed for routing and protesting conductors and cables - Construction: round pipe made of steel or aluminum; ranges from 1/2 in to 4 in - Application: most location except subject to physical damage, approved type may be barried and imbedded in concrete - EGC acceptability: Yes, when appropriate fittings are used Flexible metal conduit (FMC) -- Describe its period of use, description, application, EGC acceptability? - ANS- Period of use: - Purpose: routing and protesting conductors and cables - Construction: made of helically wound interlocking metal; made from steal (galvanized, stainless) and aluminum; ranges from 1/2 to 4 in - Construction: covering made of aluminum of steel; common size is 1/2 in - Application: Used in house wiring, used in most locations, may be barried if approved and listed; supported every 6 ft and wishing 1 ft of boxes and terminations; use nail guards - EGC acceptability: Yes, metal covering can be used Nonmetallic sheathed cable (NM) & underground feeder (UF) -- Describe its period of use, description, application, EGC acceptability? - ANS- Period of use: Dominant method since 1940s; early everyone 1920s - 1960 was cloth covered - Purpose: Designed for routing and protecting cables - Construction: factory assembled insulated conductors and typically uninsulated EGC; sheath is made of PVC; - Application: UF very simiar but designed for wet applications; may be buried, embedded in concrete w/conduit; UF is usually gray; may not be used for swimming pools, hot tub, or spa -- NM is for interior dry; support every 4 1/2 ft, use nail guards; #10 or smaller install through hole in joist - EGC acceptability: Yes, EGC conduit is integrated Problematic panelboard: Bulldog Pushmatic -- Installation period and problems? - ANSInstallation period: 1950s- 1960s less common until 1990s Problems w/design of these between 50s - 60s: - breaker not tripping - breakers energized when showing not energized Important: report panelboard built between 50s - 60s, explain risk, and recommend qualified electrician Problematic panelboard: Federal Pacific Stab-Lok "FPE" -- installation period and problems? - ANSInstallation period: mid-1950s - early 1980s Problems w/design: - breakers not tripping - breakers energized when showing not energized - arcing at breaker and busbar -dead front cover difficult to remove -breakers falling out when cover removed Important: report panelboard, explain risk, and recommend qualified electrician Problematic panelboard: Zinsco/Sinsco-Sylvania -- Installation period and problems? - ANSInstallation period: 1940s - 1970s Problems w/design: - breaker not tripping - breakers energized when showing not energized - arcing at breaker and busbar Important: report panelboard, explain risk, and recommend qualified electrician Rigid polyvinyl chloride conduit (RNC) -- Describe its period of use, description, application, EGC acceptability? - ANS- Period of use: - Purpose: designed for routing and protecting conductors and cables - Construction: Comes in two wall thicknesses (schedule 40 & 80); common sized 1/2 to 6 in - Application: can be installed in all locations; schedule 80 is used to protect against physical damage; PVC does not substitute; can be buried and embedded in concrete - EGC acceptability: No Should inspectors report electrical compliance problems? - ANSHome inspectors usually report a defect that does not comply with current requirement if he or she believes that the work should comply. Should switches installed in wet and damp areas be protected? - ANSYes, switches in damp areas (e.g., outside, etc.) should have a cover that is waterproof. They cannot be installed inside bathtub or shower surrounds. What 3 locations require a wall switch-controlled light (ceiling or wall)? - ANS1) habitable room, 2) bathroom, 3) kitchen, What 3 other locations require a wall switch-controlled light (ceiling or wall) and/or by a switch-controlled socket? - ANSOther required lights: 1) Top of stairs 2) bottom of stairs 3) Basements, attics and crawlspaces if habitable or containing serviceable equipment What 5 other locations require a wall switch-controlled light (ceiling or wall) and/or by a switch-controlled socket? - ANS1) Hallway, 2) Interior/exterior stairway, 3) Attached garage, 4) Detached garage with electricity, and 5) Exterior door What 5 things do you need to know about flexible chords? - ANS(1) Flexible cords may not be altered (2) May not substitute permanent wiring (3) May not be installed through walls, ceilings, or floors (4) Maximum of 36 inches for draft hoods and food-waste disposers (5) Maximum of 48 inches for built in washing machines and trash compactors WHAT 6 COMPONENTS REQUIRE BONDING AND OTHER SPECIAL REQUIREMENTS? - ANS(1) water and gas distribution pipes (2) electrical conduits (3) electrical equipment cases and cabinets (4) framing and sheathing (5) HVAC ducts (6) all metal parts of the service and distribution system GECs must be: - securely fastened - free of paint and rust - bonding jumper around disruptions - bonding wires are same size as GEC What are 2 the general rules regarding the amount of wires per lug. - ANS1) Energized wire and neutral : one wire per lug 2) EGC wire: two wires per lug Common exception: 15, 20, & 30 amp breaker manufactured by Square D (also called "Homeline") because they permit 2 wire per lug What are 3 track light requirements? - ANSTrack lights: 1) Not be installed in wet areas 2) Installed per manufactures recommendation & w/approved parts 3) Not in areas subject to physical damage What are 7 general receptacle requirements? - ANSReceptacles should: 1) 10-in. above floor 2) 45-in above floor for countertop (not requirement but recommended) 3) Not be ungrounded 4) Connected to EGC 5) 3-slot grounded & tamper resistant 6) Evenly distribute load in system 7) Limited to 15 amp & 20 amp What are 9 typical defects with light fixtures and ceiling fans? - ANSLight fixture and fan: 1) Loose, damaged scorched, aged, or parts are absent 2) Absent & conductors exposed 3) Gap exist between fixture, fan, & surface 3) Installed in damp or wet area 4) Inadequately supported 5) Does not function by nearby switch 6) Too close to clothes closet storage area 7) Exposed incandescent in clothes closet 8) Recessed light operates intermittently 9) Ceiling fan unbalanced (2) Aluminum can change shape, reduce in size, and become brittle—a term referred to as "creep." The smaller gauge can produce heat and increase safety risks. What are the 2 installation requirements for alarms? - ANS1) Interconnected 2) Backup power (battery) What are the 2 island receptacle requirements? - ANS1) At least 1 GFCI if more than 2- ft. wide & 1-ft. long 2) Located on cabinet if installed correctly What are the 3 common types of "problem" panelboads - ANS1) Federal Pacific Electric (FPE) 2) Zinsco 3) Pushmatic WHAT ARE THE 3 COMMON TYPES OF GROUNDING SYSTEMS? - ANS(1) Ufer ground: at least 20-feet of #4 rebar or #4 AWG bare copper wire encased in concrete. (2) A galvanized iron or steel rod or pipe or a copper rod or pipe driven at least eight feet into the ground. (3) Metal water pipe (including metal well casings) in contact with the ground for at least ten feet. What are the 3 important things with ceiling fans? - ANS1) Unbalanced fan is reportable defect 2) Nonfunctioning fan is reportable defect 3) Electrical box rated for fans & secured to framing What are the 3 problematic old wiring methods? - ANS(1) knob and tube (2) solid-conductor aluminum (3) Cloth covered NM What are the 3 problems with cloth covered NM? - ANS1) Cloth becomes brittle w/age 2) Pests chew on wire 3) No EGC What are the 3 room receptacle requirements? - ANS1) No part of wall is more than 6 ft. from receptacle 2) Average spacing is 12 ft. 3) No more than 66 in. above floor if required receptacle Note: - Floor receptacles can be used to comply - Walls include any wall 2-ft. wide (includes fixed panel doors & partition walls) What are the 3 things to remember about recessed lights? - ANS- IC are approved for insulation contact & non-IC are not approved for insulation contact - Non-IC" should be at least 3 in. from insulation Note: - Report non-IC is too close to insulation What are the 3 types of panel boards? - ANSAnswer: 1) Meter-main: meter base, service equipment, and panel board are located in one cabinet. 2) Main breaker panelboard: service equipment and panel board are located in one enclosure. 3)Main lug panelboard: panel board is served by feeder conductors (e.g., wires) from service equipment or from another panel board. Important note: panel boards downstream from service equipment are usually configured as sub panels. Reportable defect: breakers, fuses or switches are not installed in a panelboard. What are the 4 bathroom receptacle requirements? - ANSBathroom receptacles: 1) At least one GFCI protected outlet 3 ft. from outside edge of sink 2) Not located face up on countertop 3) Located on cabinet if 12 in. below countertop 4) Not installed above bathtubs & showers. What are the 4 ways to repair solid-conductor aluminum? - ANS(1) Replace copper wire in house (2) Replace with COPALUM connectors (3) Replace with AlumiConn connectors (4) Replace receptacles with CO/ALR devices What are the 5 kitchen countertop receptacle requirements? - ANS1) GFCI on countertop receptacles 2) No point on countertop more than 24-in. from receptacles 3) Average spacing is 12-ft. between receptacles 4) Includes partition walls that extend above countertops 5) Located 20-in above countertop or enclosed in space (e.g., appliance garage) What are the 5 types of fuse styles OPDs and are they appropriate to use? - ANS1) Type T: Edison base 2) Type S base 3) Type W 4) Type L 5) Type D Note: - OK for lighting circuits - Not OK for circuits servicing motors because motors can open fuse What are the 6 important consideration when analyzing wire during a home inspection? And, what is the universal characteristics of conduit? - ANSThese are the important considerations: (1) When was the wire installed? This is so you can determine if it has a common defect or is being used for its intended purpose. (2) What type of wire is it? This is so you can determine if it is being used correctly. (3) Is the wire being used for its intended purpose. (4) Is the conduit intended for wet or dry areas? Does the conduit protect against physical damage? Can the wire be buried or embedded in concrete? (5) Does the conduit have a EGC? (6) Is the conduit fastened to wall at recommended intervals What is the universal conduit characteristics: - The purpose of conduit is to route and protect cables and safely move electricity What are the 7 requirements around a electrical service equipment, panel boards, and equipment? - ANS1) located were access is safe, 2) not in storage closets, clothes closets, bathrooms and above stairs 3) working space at least 36 in. deep, 30 in. wide, and 72 in. tall. 4) cabinet door should swing open by 90 degrees 5 area above is for electrical equipment and should not contain plumbing or HVAC 6) panel should not be more than 79 in. high 7) no min height requirement What are the 8 common types of modern electrical wiring? - ANS(1) Armored cable (AC): (2) Electric nonmetalic tubing (ENT): (3) Flexible metal conduit (FMC): (4) Intermediate metal conduit (IMC) and rigid metal conduit (RMC): (5) Liquidtight flexible metal conduit (LFMC) and liquid tight flexible conduit (LFC): (6) Metal-clad cable (MC) (7) Nonmetallic Sheathed Cable (NM) and underground feeder (UF) (8) Rigid Polyvinyl Chloride Conduit (RNC) (9) Electric metalic tubing (EMT) What are the 8 typical defects of grounding and bonding? - ANSGrounding defects: - damaged, disconnected, or loose at grounding electrode connection -too small for service (min. #8 < 160 AMP & #4, #6 > 150 AMP) (4) Melted insulation and charred conductors: indicates loose connection at lug or overcurrent that was not interrupted by OPD (5) Conductors not inserted straight into terminals (6) screws with points used to secure enclosure cover: points could penetrate conductor insulation and energize the enclosure (7) Branch circuit not labeled: branch circuits should be labels with permanent marker and describe different circuit. Identification of occupant's room in not acceptable. (8) Energized neutral conductors not marked as energized: energized neutral wire may be used but must be marked at all accessible points (usually done with tape or marker) (9) Circuit breaker and panelboard from different manufacturer: they work as a system and mismatching is not allowed (10) Absent or improper handle panel ties: Must be able to shut off both together; only approve handle ties may be used; improvised handle ties (wire, nails, screws, etc.) may not be used (11) Absent tabs or knockouts: electrical shock hazard; tabs/knockouts must be replaced w/original material (12) Low voltage components inside enclosure and conduit: low voltage components (telephone wire, etc.) not allowed unless physically separated by non-conductive guard (13) too many circuit breakers on panelboard in wrong slots: panel states how many and where they go (14) panelboard ampacity lower than service entrance or feeder ampacity: panelboard state maximum ampacity that serves boards; conductors may be less but not more (15) Fused neutral: neutral connectors may not be connected to OPD What are the typical defects in subpanels? - ANS(1) EFCs and neutral conductors are connected to same terminal bar. (2) EGC terminal bar is not bonded to enclosure (3) Refer to typical panelboard defects for other considerations What are unfinished basement receptacle requirements? - ANS- 1 GFCI protected receptacle installed in addition to appliance receptacles (HVAC, etc.) What does IC stand for in regards to recessed lights? - ANS- Insulation contact What does subject to physical damage refer to in regards to electrical components and what are the requirements? - ANSNo clear definition is provided but these situations apply: - NM, AC, and UF installed under kitchen cabinets - cable within reach in unfinished walls - cable installed within 7 feet vertically and 6 feet horizontally from attic access What is a double tap? No, we're not taking about the wrestling move. - ANSA common defect found in an enclosure is when multiple wires are inserted into a single lug. What is a false (fire) alarm? - ANS- Disconnect alarm What is a short circuit? - ANSA short circuit is an electrical circuit that allows a current to travel along an unintended path with no or a very low electrical impedance. What is copper clad aluminum wire? When was it produced? - ANSCopper clad aluminum wire is aluminum wire has an aluminum core and copper exterior. This rare wire was produced in the 1970s and is not known to share the same problems as solid- conductor aluminum. What is electrical myth #1? - ANSMyth 1: electricity wants to return to ground Truth: electricity want to return to its source What is electrical myth #2? - ANSMyth 2: electricity takes the path of least resistance back to its source. Truth: electricity takes all available paths. What is the bend radius of wire? - ANSNot smaller than 5 times the cables width WHAT IS THE BEST WAYS TO REMEMBER BONDING REQUIREMENTS? - ANSIF IT IS METAL AND IS OR COULD BE NEAR ELECTRICAL WIRES, THEN IT PROBABLY NEEDS TO BONDED TO GROUNDING WIRE OF UTILITY. What is the clearance requirements above building openings for an electrical service drop? - ANSAnswer: - 3 ft. above a window that opens - 3 ft. to each side of a handrail What is the clearance requirements above ground for an electrical service drop? - ANSAnswer: - 10 ft above ground of sidewalk - 12 ft above residential driveway - 18 ft above public street, alley, or parking lot. What is the common defect found when inspecting OPDs? - ANSThe OPD is protecting a conductor (e.g., wire) that is too small, which allows a higher amount of current to pass through the conductor. The higher current create heat and could result in a fire. What is the difference between GFCI and AFCI? - ANSGFCI detects ground faults and AFCI detects arc faults. What is the difference between grounding and bonding? (P. 173) - ANS- both are safety related systems - grounding system limits voltage surges and shunts them safely to ground - bonding clears ground faults in non-electrical carrying material by providing a path to ground What is the difference between volt, amp, and ohms? - ANS- Voltage measured in volts - Current measured in amps - Resistance measured in ohms Helpful analogy: - Voltage is equivalent to water pressure - Current is equivalent to flow rate - Resistance is like the pipe size. - Voltage is water pressure, current is flow rate, and resistance is pipe size What is the formula for Ohm's Law? - ANSI (current in amps) = E(voltage in volts)/R(resistance in ohms) Helpful saying: - Amps & volts & ohm - REI - Amp=volts/ohm What is the formula for service load? - ANSTo calculate service load, add the demand of the following: (1) lights and receptacle circuits, (2) kitchen and laundry receptacle circuits, (3) electric appliances, and (4) heating and cooling equipment. Number 1, 2, and 3 are reduced by a factor to account for not being active simultaneously. What is the maximum allowable height for a wall switch? - ANS- max 79 in. above floor when in up position What is the minimum voltage requirement for residential electrical service? - ANS- answer: 240 volt single phase - 240 and 208 three phase are uncommon - 120 volt can be a reportable defect because most appliance require 240 volt What is the name of the two most common switches used in modern construction? - ANS1) Rocker switch 2 snap switch What is the problem with Edison fuses? - ANSProblem: - Fuses are interchangeable - Results in lrg. fuse in place of sm. fuse - Over fusing causes fires