Free MI Journeyman Electrician Exam Flashcards

MCL 339.5715 requires you to be at least 20 years old with at least 8,000 hours of experience obtained over a period of at least 4 years, performed under the direct supervision of someone licensed under Article 7. Hours alone are not enough - crowding 8,000 hours into three years does not satisfy the 4-year clock.

Under MCL 339.5715(3), failing the electrical journeyman exam twice within 2 years makes you ineligible to sit again for at least 1 year from the date of the second failure. After that year you must also give the board proof that you completed an approved course on Michigan electrical code, electrical fundamentals, or electrical theory.

An apprentice must register with the board within 30 days after employment (MCL 339.5717(1)), and the ratio is 1 journeyman or master electrician to no more than 3 registered apprentices, enforced on a jobsite basis. Counting apprentices company-wide instead of per jobsite is the classic violation.

Permits expire 180 days after issuance and are extended 180 days from the last inspection date, and the AHJ may grant one additional 180-day extension for a satisfactory reason. Permits are not transferable, and a copy must be posted or otherwise readily accessible at each work site.

The grounding electrode conductor connects the system and enclosures to the earth electrodes and is sized from Table 250.66, while the equipment grounding conductor provides the low-impedance fault-clearing path back to the source and is sized from Table 250.122 by overcurrent-device rating. Sizing an EGC off Table 250.66 (or vice versa) is a common exam trap; note that 250.66(A) never requires more than 6 AWG copper where that conductor is the sole connection to a rod, pipe, or plate electrode.

A rod electrode must be at least 8 ft long and in contact with the soil (250.52(A)(5)), and where rods are used together they must be at least 6 ft apart (250.53(A)(3)). A single rod must be supplemented by an additional electrode unless it is tested and shows 25 ohms or less to ground (250.53(A)(2), Exception).

Michigan amends 250.104(B): a listed CSST gas piping system must be bonded to the electrical service grounding electrode system with a jumper not smaller than 6 AWG copper, landed on metallic pipe or a fitting between the point of delivery and the first downstream CSST fitting. That 6 AWG minimum is a Michigan requirement, not a plain NEC number, and once bonded this way the system is considered effectively bonded regardless of how much CSST is installed.

Regardless of the ampacity you calculate from Table 310.16, copper conductors are limited to 15 A for 14 AWG, 20 A for 12 AWG, and 30 A for 10 AWG unless a specific exception applies. This is why a 12 AWG THHN conductor rated 30 A at 90 degrees C still cannot be protected at 30 A on a general branch circuit.

You may use the next higher standard rating from 240.6(A) when the conductor ampacity does not match a standard size, the device is rated 800 A or less, and the circuit does not supply receptacles for cord-and-plug-connected loads on a multi-outlet branch circuit. Above 800 A the rule flips: 240.4(C) requires the device rating to not exceed the conductor ampacity.

The 2023 NEC's 240.24(E) prohibits overcurrent devices other than supplementary devices in bathrooms, showering facilities, and locker rooms that contain showering facilities. Panelboards must also stay readily accessible, out of clothes closets and bathrooms, and away from easily ignitible material.

Michigan rewrites 334.10 and 334.12(A): NM and NMC are permitted in one- and two-family dwellings with their garages and storage buildings, in multifamily dwellings and their detached garages, and in other structures over one floor above grade only where concealed behind assemblies with at least a 15-minute finish rating. It may never be used as service-entrance cable, in commercial garage classified locations, in hoistways, or embedded in concrete.

NM cable must be secured within 12 in. of every box, cabinet, or fitting and at intervals not exceeding 4.5 ft. The relief is single-gang nonmetallic boxes without internal clamps, where the cable may instead be fastened within 8 in. of the box measured along the sheath.

EMT must be securely fastened within 3 ft of each outlet box, junction box, cabinet, or termination and supported at intervals not exceeding 10 ft. Rigid metal conduit and IMC use the same 3-ft rule at boxes but allow longer intervals based on conduit trade size in Table 344.30(B)(2) - up to 20 ft for trade size 3 and larger.

Typical minimums are 24 in. for direct-buried cable, 18 in. for nonmetallic raceway listed for direct burial, and 6 in. for rigid metal conduit or IMC. A residential branch circuit rated 120 V or less that is GFCI-protected and protected at 20 A or less may be buried at 12 in.

Each conductor counts as 2.00 cubic in. for 14 AWG, 2.25 for 12 AWG, 2.50 for 10 AWG, 3.00 for 8 AWG, and 5.00 for 6 AWG. Conductors that pass through the box without splice count once, and conductors that both enter and leave through a cable or raceway are still one count each.

Each yoke or strap holding one or more devices counts as a double volume allowance, based on the largest conductor connected to that yoke - not the largest conductor in the box. A switch fed with 12 AWG therefore adds 4.5 cubic in., which is what pushes many two-device boxes over the limit.

One or more internal cable clamps together add a single allowance based on the largest conductor in the box (314.16(B)(2)). Up to four equipment grounding conductors also count as one allowance based on the largest EGC, with a 1/4 allowance for each additional EGC beyond four (314.16(B)(5)).

One conductor may fill 53% of the raceway cross section, two conductors 31%, and more than two 40%. Note 4 to the table allows 60% fill in a nipple no longer than 24 in., and that nipple also escapes the ampacity adjustment factors.

At least 6 in. of free conductor must be left at each outlet, junction, and switch point, measured from where it emerges from the raceway or cable sheath. Where the opening is less than 8 in. in any dimension, each conductor must also extend at least 3 in. outside that opening.

For a straight pull, the box length must be at least 8 times the trade size of the largest raceway. For angle or U pulls, the distance from the raceway entry to the opposite wall must be at least 6 times the largest raceway trade size, plus the trade sizes of the other raceways in the same row on that wall.

The service disconnecting means for a one-family dwelling must be rated not less than 100 amperes, 3-wire. Smaller minimums apply elsewhere - 15 A for a one-circuit installation, 30 A for a two-circuit installation, and 60 A for all other installations under 230.79(D) - so read the occupancy before you answer.

Two to six service disconnects are still permitted per service, but each must now be in its own enclosure, in a panelboard with a main, in a separate barriered vertical switchboard section, or in a separate switchgear compartment. Six breakers stacked in one panel as the service disconnecting means is no longer acceptable.

Part 8 adds 230.85: one- and two-family dwellings need an emergency disconnecting means in a readily accessible outdoor location on or within sight of the dwelling, with a short-circuit current rating at least equal to the available fault current. Each disconnect must be a service disconnect and must be marked EMERGENCY DISCONNECT, SERVICE DISCONNECT; multiple disconnects must be grouped.

A surge-protective device is required where a service (230.67), feeder (215.18), or outside feeder/branch circuit (225.42) supplies dwelling units, dormitory units, hotel and motel guest rooms and suites, or nursing home and limited-care areas used exclusively as patient sleeping rooms. Replacing that service equipment triggers the SPD requirement too.

It must be installed at a readily accessible location either outside the building or inside nearest the point of entrance of the service conductors, and it may not be in a bathroom. Running unprotected service-entrance conductors deep into a building past the nearest practical point is the violation this rule exists to prevent.

The main bonding jumper ties the grounded (neutral) conductor to the equipment grounding system at the service disconnect, and 250.142 prohibits using the grounded conductor for equipment grounding on the load side. Bonding neutral to ground in a downstream panel puts normal neutral current on metal enclosures and the equipment grounding conductors.

Branch-circuit conductors must have an ampacity of at least 125% of the motor full-load current taken from Table 430.248 or Table 430.250 - the code table value, not the nameplate. Using nameplate amps here is the single most common motor-calculation error on licensing exams.

For continuous-duty motors over 1 hp, the separate overload device is set at no more than 125% of the motor nameplate full-load amperes when the marked service factor is 1.15 or greater or the temperature rise is 40 degrees C or less; all other motors use 115%. Overloads are the one place you must use the nameplate rather than the code table.

Using the table full-load current, the maximum is 300% for a non-time-delay fuse, 175% for a dual-element time-delay fuse, and 250% for an inverse-time circuit breaker. If the calculated value does not match a standard rating, 430.52(C)(1)(a) permits the next higher standard size; the 2023 NEC renumbered old Table 430.52 as Table 430.52(C)(1) and turned its exceptions into list items.

At a dwelling unit, at least one 125-volt, 15- or 20-ampere receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of the pool, and no more than 6 ft 6 in. above the floor or grade. The 6-ft minimum keeps cords out of the water while the 20-ft maximum discourages extension cords.

Equipotential bonding uses a minimum 8 AWG solid bare copper conductor, and the perimeter surface to be bonded extends 3 ft horizontally beyond the inside walls of the pool. This bonding grid only equalizes voltage in the pool area - it is not required to be run to a panelboard, service equipment, or grounding electrode.

Class I covers flammable gases and vapors, Class II combustible dust, and Class III ignitible fibers and flyings. Division 1 means the hazard is present in normal operation, while Division 2 means it appears only under abnormal conditions, which is why Division 2 permits less costly wiring methods.

Section 220.41 sets the dwelling minimum unit load at 3 volt-amperes per square foot, and 220.5(C) says the floor area is computed from outside dimensions, excluding open porches and unfinished areas not adaptable for future use. This value moved from 220.12 in the 2020 NEC, and the 2023 edition also removed garages from the exclusion list - garage floor area now counts.

Each required 20-ampere small-appliance branch circuit and each laundry branch circuit is computed at 1,500 volt-amperes (220.52), and a dwelling must have at least two small-appliance circuits, one laundry circuit, and one 20-ampere bathroom circuit under 210.11(C). Those VA values are added to the general lighting load before demand factors are applied.

A household electric clothes dryer is calculated at 5,000 volt-amperes or the nameplate rating, whichever is larger (220.54). Household ranges use the demand table in 220.55, where a single range rated not over 12 kW is calculated as an 8 kW demand rather than at nameplate.

At least one wall-switch-controlled lighting outlet is required in every habitable room, kitchen, and bathroom, plus hallways, stairways, attached garages, and outdoor entrances or exits with grade-level access. Storage or equipment spaces such as attics and basements need a lighting outlet controlled at the point of entry.

Protection applies to 125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground in the listed locations, and the 2023 edition expanded 210.8(A)(6) to all dwelling kitchen receptacles - not just those serving countertops. The old shorthand of 15- and 20-ampere, 125-volt receptacles is outdated.

The branch circuit or outlet supplying certain appliances rated 150 volts or less to ground and 60 amperes or less, single- or three-phase, must be GFCI protected. The 2023 additions are electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers, and microwave ovens, joining items such as dishwashers, sump pumps, and vending machines on the 12-item list.

AFCI protection is required for 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices in dwelling-unit kitchens, bedrooms, living areas, hallways, laundry areas, and similar rooms. The 2023 NEC also extended it under 210.12(D) to areas used exclusively as sleeping quarters in fire, police, ambulance, rescue, and ranger stations and similar locations.

Receptacle outlets serving countertops or work surfaces must be located on or above the surface but not more than 20 in. above it, or in listed countertop or work-surface assemblies. For islands and peninsulas the 2023 NEC no longer mandates a receptacle, but provisions for adding one later must be built in.

All 15- and 20-ampere, 125-volt and 250-volt non-locking receptacles in the listed areas must be listed tamper-resistant. The 2023 edition added residential care and assisted-living facilities, rehabilitation facilities, group homes, foster care facilities, nursing homes, psychiatric hospitals, and public or common areas of agricultural buildings.

Article 725 now covers only Class 2 and Class 3 power-limited circuits, Class 1 power-limited circuits moved to new Article 724, and cable requirements for power-limited, fault-managed, and optical fiber installations moved to new Article 722; Article 720 was deleted. Citing 725 for a Class 1 rule is a wrong answer under the code Michigan now enforces.

Both are supplied from listed power sources whose voltage, current, and volt-ampere limits come from Chapter 9, Tables 11(A) for alternating current and 11(B) for direct current. Class 2 is limited enough to be considered safe from shock and fire ignition, while Class 3 permits higher voltage and therefore requires additional protection against electric shock.

Class 2 and Class 3 conductors may not occupy the same cable, raceway, enclosure, or cable tray as electric light, power, Class 1, or non-power-limited fire alarm conductors unless a barrier or one of the specific permissions in 725.136(B) through (I) applies. Dropping a thermostat cable into a box with a 120-volt branch circuit is the everyday version of this violation.

LARA states that all Michigan electrical examinations are currently based on the 2023 NEC, the 2023 Michigan Electrical Code Part 8 rules, 1972 PA 230 (Stille-DeRossett-Hale), 2016 PA 407 (Skilled Trades Regulation Act), and their promulgated rules. Where Part 8 amends, adds, or rescinds an NEC section, the Michigan text is the enforceable answer.

For equipment operating at 0-150 volts to ground under Condition 1, the working space is at least 3 ft deep, at least 30 in. wide or the width of the equipment if greater, and 6.5 ft high. The 2023 NEC added 110.26(A)(6), requiring the grade, floor, or working platform to be kept clear and as level and flat as practical for the full depth and width.

Unless the equipment or terminals are listed for higher, circuits rated 100 amperes or less and conductors 14 AWG through 1 AWG must be sized from the 60 degree C column, while larger circuits default to the 75 degree C column. A 90 degree C conductor may still be used, but only its higher rating is used for derating - the final ampacity may not exceed the terminal rating.

E = I x R and P = I x E, which combine to P = I squared x R for a resistive load. Because heat rises with the square of current, doubling the current through a fixed resistance quadruples the heat; halving the resistance at a fixed voltage doubles the current and therefore doubles the power (P = E squared / R).

In a wye system, line voltage equals 1.732 times phase voltage (120 V phase gives 208 V line) while line and phase current are equal; in a delta system, line and phase voltage are equal while line current equals 1.732 times phase current. Three-phase power is P = 1.732 x line volts x line amps x power factor.

For a single-phase circuit, VD = (2 x K x I x L) / circular mils, with K about 12.9 for copper and 21.2 for aluminum; substitute 1.732 for the 2 on a three-phase circuit. NEC informational notes recommend holding branch-circuit drop to 3% and total drop to 5%, but those are recommendations, not enforceable requirements.