MASS REVIEW
What is the maximum delay setting of the service GFP system for ground fault currents of 3000 amperes and above?
1 second. **refer to section 230.95(A)**
A cables installed in exposed or concealed locations under metal-corrugated sheet roof decking is required to be supported so there is not less than _________ measured from the lowest surface of the roof decking to the top of the cables.
1-1/2 in **Refer to Section 300.4(E)**
What size SSBJ is required for a flexible metal conduit that feeds a panel board from a 112.5kVA step-down transformer and contains 400 kcmil copper secondary conductors?
1/0 AWG copper **SSBJ is sized using Table 250.102(c)**
The minimum required airspace between exposed boxes, fittings, raceways, and cables used in locations where walls are frequently washed is:
1/4in. **Refer to Section 300.6(D)**
Approved drainage openings for boxes, conduit bodies, outlet box hoods, and fittings installed in wet locations shall not be smaller than _________.
1/8 **refer section 314.15**
What is the maximum length of the transformer secondary conductors of a single-phase 480V:120V transformer?
10 ft. 25 ft. 25 ft., if installed in a supervised industrial location. (none of the above) **section 240.21(C)(1)**
What is the minimum distance from fence to live parts for a 750 KVA, 12470/7200 to 208/120 volts oil fluid transformer?
10 ft. **since equipment is over 1000 volts, nominal, table 110.31 provides minimum distance form fence to live parts. The nominal voltage falls under 1001 - 13,799 range which means that the minimum distance is 10 ft**
All three-phase receptacles rated 150 volts to ground or less and ________ amperes or less in other than dwelling units are required to have GFCI protection.
100 **refer to section 210.8(B)**
What is the ampacity of eight 1/0 AWG THHN/THWN, copper current-carrying conductors installed in a single raceway in a dry location for a length that exceeds 50ft.?
119 amperes **refer to table 310.15(B)(3)(a). Find adjustment factor of 7-9 current-carrying conductors. Then 310.15.(B)(16) gives us the ampacity of the conductors in question. Since we're adjusting ampacity, us 90C column, where we see that the ampacity of 1/0 AWG copper conductors is 170 amperes. So, (170 amperes) x 70% = 119 amperes.**
The maximum number of 12 AWG conductors in a metal square box with a trade size of 4-11/16 x 1-1/2 in. is ________.
13 **refer to table 314.16(A)**
What is the minimum required distance between 2-1/2 in. conduit entries that enclose the same feeder conductors where the conduit enters a pull box on the side and leaves the pull box on the top?
15 in. **Section 314.28(A)(2)**
Using the contents only, find the answer to the following question: Receptacles and cord connectors shall be rated not less than ____ amperes, 125 volts, or ____ amperes, 250 volts, and shall be of a type not suitable for use as lamp holders.
15,15 contents > chapter 4 > article 406 > 406.3(B)
Vertical runs of sideways used for elevator conductors shall be securely supported at intervals not exceeding _______ ft.
15. **Refer to Section 620.32** Special Equipment
What is the full load current in amperes of a 10 horsepower direct current motor that operates 500 volts DC
18 **using index or contents, find that answer lies somewhere inside Chapter 4 and Article 430 - Motors, Motor Circuits, and Controllers. Conversion Table 430.247 Full Load Current in Amperes, Direct Current Motors, has the answer to our question.**
What is the minimum clearance for an overhead feeder that is installed above a public road?
18 ft. **refer to section 225.18(5)**
What is the rating of a branch circuit that consists of 10 AWG conductors and is fed from a 20-ampere circuit breaker?
20 amperes **refer to 210.18.**
The minimum burial depth of a PVC Schedule 40 conduit that is installed under the parking lot is:
24 in. **Refer to Table 300.5 PVC is a nonmetallic conduit, so look at Column 3.**
Type STO flexible cord shall be durably marked on the surface at intervals not exceeding __________.
24 inches **Refer listed flexible cords** 400.6(A) shall be durably marked on the surface at intervals not exceeding 610mm (24in) with the type designation, size, and number of conductors.
Adjustment factors shall not apply to conductors in raceways having length not exceeding _________.
24in. **Refer to Section 310.15(B)(3)(a)(2)**
What is the minimum size of a wire-type aluminum common grounding electrode conductor of a separately derived system?
250 kcmil **refer section 250.30(A)(6)(a)(1).**
Round access openings for manholes shall not be less than _________ inches in diameter
26 **refer to Section 110.75**
The maximum allowed cord length for connection of office cubicle panels and workstations is:
2ft. **Refer to Section 605.5(3)** Special Equipment
What is the minimum required working space for electric sign ballasts and transformers?
3 ft high by 3 ft wide by 3 ft deep **Section 600.21(D)**
Each EMT conduit run between termination point is required to be securely fastened within __________ of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination.
3 ft. **refer to section 358.30**
Branch circuits that supplies neon tubing installations shall not be rated in excess of:
30 Amperes. **Section 600.5(A)(1)** Special Equipment
What is the minimum size of a disconnect switch that supplies a park pavilion with two 120V individual branch circuits?
30 amperes. **refer to section 225.39(B)**
Snap switches can be grouped in enclosures with other snap switches or receptacles if the voltage between the adjacent devices does not need ________ volts.
300 Section 404.8(B) Voltage Between Adjacent Devices. A snap switch shall not be grouped or ganged in enclosures with other snap switches, receptacles, or similar devices, unless they are arranged so that the voltage between adjacent devices does not exceed 300 volts, or unless they are installed in enclosures equipped with identified, securely installed barriers between adjacent devices.
a cable installed in exposed or concealed locations under metal-corrugated sheet roof decking is required to be supported so there is not les than _______ measured from the lowest surface of the rock decking to the top of the cable.
300.4 (E) a cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than 38mm (1.5 in)
What is the minimum required width of working space of an electrical panel board with the following dimensions: W. = 20in. D. = 5.75in H. = 50in.?
30in. **refer to section 110.62(A)(2).**
A 200A, 3-pole circuit breaker in the main distribution in an office building supplies a 200A, 208/120V, 3-phase, 4-wire panel board via feeder that consists of two sets of 2" conduits. Each set of conduits includes three 1 AWG ungrounded conductors, one 1 AWG neutral conductor, and one 6 AWG-stranded equipment grounding conductor. All conductors are copper. This feeder is not in compliance with which of the following:
310.10(H)(1) **conductors are allowed to be connected in parallel only in sizes 1/0 AWG and larger**
What is the maximum size of a DC system GEC connected to a concrete-encased electrode?
4 AWG copper **see section 250.166(D)**
What is the permitted demand factor for a multifamily dwelling unit that consists of 9 units?
43% **refer to table 220.84**
Which of the following conductors are not permitted to be installed in parallel?
4AWG THHN copper conductors **section 310.10(H)(1)**
A disconnect of a guard shack building is supplied with a feeder that contains 1 AWG copper conductors. What size copper GEC is required for the building disconnect?
6 AWG **The GEC is sized using Table 250.66**
What is the minimum size of individual service conductors over 1000 volts, nominal?
6 AWG **refer to section 230.202(A)**
What is the minimum conductor size between the surge arrester and the surge arrester and the grounding connection?
6 AWG. **refer to section 280.23**
The maximum rating of the overcurrent device that protects pipe organ circuits is
6 amperes. **Refer to Section 650.8** Special Equipment
Appliance receptacle outlets installed in a dwelling unit for a specific appliance must be installed within ______ of the intended location of the appliance.
6 ft. **refer to section 210.50(C)**
Termination provisions of equipment for circuits rated 100 amperes of less, or marked for 14 AWG through 1 AWG conductors (provided the ampacity adjustment is not required and the equipment is not listed and identified for use with the higher temperature ratings), shall be used only for conductors rated ________.
60 degrees celsius **refer to Section 110.14(C)(1)(a)(1)**
The overcurrent protective device of an individual power source feeding a fire pump shall not open within 2 minutes at _______ percent of the full load current of the fire pump.
600. **Section 695.4(2)(2)(a). Overcurrent protection of an individual power source must be sized to carry locked-rotor current indefinitely as required in 695.3(A). This only applies to the overcurrent protection device, and not to the conductors feeding the fire pump.**
What is the minimum size of the underground service conductors?
8 AWG copper **refer to section 230.31(B)**
What is the minimum vertical clearance above the roof of overhead service conductors at 6 ft from the edge of the roof?
8 ft. 10 ft. 12 ft. (None of the above.) **section 230.24(A). The rule applies only to the service conductors located directly overhead above the roof or at a distance of not less than 3 ft in all direction from the edge of the roof. since the question is asking for the clearance at 6 ft from the edge of the roof, this rule does not apply**
Which of the following is considered to be readily accessible?
A GFCI microwave outlet located in the wall cabinet behind the microwave. A GFCI refrigerator outlet located behind the refrigerator A disconnect switch that is obstructed by a freestanding shelving unit. (A GFCI outlet located in a kitchen above the counter top.) **check the definition accessible, readily,
The positive polarity of a 10 AWG DC system branch circuit is identified by:
A continuous red outer finish. **refer to section 210.5(C)(2)(a)(1)**
What is the NEC permitted method for the identification of a 2 AWG grounded conductor?
A continuous white outer finish. **refer to section 200.6(B)**
What is a disconnecting means?
A device, or group of devices, or other means by which the conductors of a circuit can be disconnected form their source of supply
Section 511.10 (A) is an example of
A mandatory rule. This is an example of a mandatory rule. 90.5(A) for description of mandatory rules.
Main bonding jumper and system bonding jumper shall be which one of the following?
A wire. Bus Screw (Any of the above) **see section 250.28**
Type MI cables are permitted in which of the following installations?
All of the above. **Refer to Section 332.10. Type MI cables are permitted in Class 1, Class 2, and Class 3 locations, but more about that in Module 10**
When is the motor frame of an electrically operated pipe organ required to be connected to EGC?
Always **per section 250.112(B), generator and motor frames in electrically operated pipe organs are always required to be connected to an EGC (unless effectively insulated from the ground and the motor driving it.) The requirement does not depend on voltage, as stated in 250.112**
What is considered a kitchen in NEC code?
An area with a permanent provision for a cooking appliance and a sink. **See the definition for Kitchen**
A snap switch suitable only for use on on ac circuits is permitted to control motor loads if
Article 404 Switches Section 404.14(A)(3) Motor loads not exceeding 80 percent of the ampere rating of the switch at its rated voltage
Which of the following areas requires listed tamper-resistant receptacles?
Article 406 Receptacles, Cord Connectors, and Attachment Plugs (Caps) Section 406.12 Tamper-Resistant Receptacles. (4) Preschools and elementary education facilities
If a switchboard is used as service equipment, it must be provided with a
Article 408 Switchboards, Switchgear, and Panelboards 408.3(C) each switchboard, switchgear, or panel board, if used as service equipment, shall be provided with a main bonding jumper.
A cord that supplies low-voltage lighting is permitted to be installed not less than _____ ft above the finished floor.
Article 411 Low-Voltage Lighting 411.6(D)(2) Insulated Conductors: insulated secondary circuit conductors shall be of the type, and installed as, described in 1-3. (2) Conductors, cord, or cable of the listed system and installed not less than 2.1m (7ft) above the finished floor unless the system is specifically listed for a lower installation height
If the branch circuit supplies a single non-motor-operated appliance, the rating of overcurrent protection shall not exceed
Article 422 Appliances Part 2-Installation-Section 422.11(E)(2) Not exceed 20 amperes, if the overcurrent protection rating is not marked and the appliance is rated 13.3 amperes or less.
Space heating cables are permitted in which of the following areas?
Article 424 - Fixed electric space-heating equipment Sections 424.38(B) and 424.45 PART IV Marking of Heating Equipment
Which of the following devices can be used as a disconnecting means for a 1hp, 120 volts stationary motor?
Article 430 MOTORS Part IX. Disconnecting Means Section 430.109 (C) *1* a general use switch an ampere rating not less than twice the full-load current rating of the motor
Which of the following units are used to express the load of an electric circuit?
Electric current (amperes) Power (volt-amperes or watts) Horsepower (hp) All of the above are correct
Informational notes are enforceable as requirements of NEC Code.
False. **info notes are explanatory material of the Code. Informational only, non enforceable.**
True of false? Equipment 1 (240 volts, 1-phase, 5 amperes) has a higher load in volt-amperes than Equipment 2 (120 volts, 10 amperes)
False. Equipment 1 in volt-amperes is calculated as: S = V x I = (240 volts) (5 amperes) = 1200 volt-amperes While equipment 2 load in volt-amperes is calculated as: S = V x I = (120 volts) (10 amperes) = 1200 volt-amperes. therefore, both have the same load.
Type FMT conduit is not permitted to be used in which of the following locations?
In hoistways. **Refer to Sections 360.10 and 360.12**
Which of the following is permitted in the equipment dedicated space?
Lay-in suspended ceiling **refer to Section 110.26(E)(1)(a), (b), (c), and (d)
For electrical rooms that contain equipment rated 800 A or more, the personnel doors shall be equipped with which of the following?
Listed panic hardware. **refer to Section 110.26(C)(3)**
Which of the following methods can be used for the ID of equipment grounding conductors in a multi conductor cable?
Marking the exposed insulation with green tape or green adhesive labels. **refer to section 250.119(B)**
Can service conductors be connected to the service disconnecting means using soldering?
No, connections that depend on solder are not permitted. **refer to section 230.81**
Can a tree be used as support for overhead 240 volts, 1-phase, 3-wire branch circuit conductors?
No, vegetation, including trees, is not permitted to be used for support of over. **refer to section 225.26**
Can a tree be used for the support of service conductors?
No, vegetations cannot be used for service conductor support **refer section 230.10**
Are direct-buried conductive fiber cables always required to be separated by at least 12 in. from electric light and power conductors?
No. **Chapter 7, Article 770 - Optical Fiber Cables, and section 770.47 (B).**
What type of outer covering does a TW Type conductor have?
None. **Refer to Table 310.104(A)**
On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is ______ in color or by other effective means.
Orange **refer to Section 110.15**
Which of the following cannot be used as EGC?
Rigid metal conduit. (Flexible metallic tubing containing conductors protected by 30 amperes circuit breaker) The copper sheath or mineral-insulated, metal-sheathed cable Type MI Listed electrically continuous metal auxiliary gutters.
What is the minimum required spacing between a non-type IC luminaire recessed parts and insulation material?
Section 410.16(A)(1) Luminaires in Clothes Closets (A) Luminaire Types Permitted. Only luminaires of the following types shall be permitted in a closet: (1) Surface-mounted or recessed incandescent or LED luminaires with completely enclosed light sources
Service-entrance conductors in a cable tray must comply with which of the following requirements?
Single conductors must be 1/0 and larger Single conductors must be CT rated The warning label "Service-Entrance Conductors" must be installed every 10 ft. **refer to section 230.44**
What is the maximum number of service disconnects (circuit breakers) that can be grouped together in a switchboard with a surge protective device that is also protected by a circuit breaker?
Six, plus the circuit breaker for the surge protective device. **refer to section 230.71(A)**
Which of the following equipment is not permitted to be installed on the supply side of the service disconnect?
Step-down transformer **items a, c, and d are permitted to be installed on the supply side of the service disconnect per sections 230.82(1), 230.82(4), and 230.82(6), respectively**
Where multi conductor cable is used with a suspended pushbutton station for overhead hoist control, the station shall be supported in a manner that protects the electrical conductors against
Strain. **Section 610.11(D)**
What size of grounding electrode conductor is required for service that has four sets or 500 kcmil
TABLE 250.66 GEC SIZE see informational notes 1 & 2
The grounded conductor from the transformer to the service equipment must not be smaller than specified in:
Table 250.102(C)(1)
What table is used to size the main bonding jumper and system bonding jumper?
Table 250.102(C)(1) **This table is also used for the sizing of other conductors and jumpers**
Which of the following surge protective device types can be used for the protection of a branch panel board that is fed from a step-down transformer (separately derived system)?
Type 1 or Type 2 **refer to sections 285.23(A)(2) and 285.24(C)**
Underground service conductors are not permitted to be installed in
Type EMT conduit **refer to section 230.30(B) for permitted wiring methods**
using the method of elimination, answer the following question: Which of the following conduit types can be installed in areas where they can be subject to severe physical damage?
Type RMC using contents, can quickly check Uses Permitted and Uses Not Permitted sections for all of the four listed conduit types.
Which of the following systems are not permitted in the cable trays containing electrical conductors?
Water pipe Gas pipe Drainage pipe (None of the above.) **refer to section 300.8**
Power-Limited Fire Alarm Circuit (PLFA) is
a fire alarm circuit powered by a source that complies with 760.121 **answer in section 760.2 pg. 70-620**
A grounding electrode conductor must be connected in an enclosure on the supply side of the disconnecting means to
all of the following; grounded service conductors(s). equipment grounding conductor installed with the feeder. supply-side bonding jumper (all of the above) **section 250.64(D)(3)**
Where two or more branch circuits supply devices or equipment on the same yoke or mounting strap, a means to simultaneously disconnect the ungrounded supply conductors shall be provided
at the point at which the branch circuits originate **refer sections 210.7**
Circuits not exceeding 120 volts, nominal, between conductors, are permitted to supply which of the following?
cord-and-plug-connected utilization equipment the terminals of lamp holders applied within their voltage ratings permanently connected utilization equipment (all of the above) **refer to section 210.6(B)(1) and (3)**
Using the Index only, find out if a wet-niche luminaire is to be mounted in a(an):
forming shell. main term is luminaire and sub term is wet-niche
A (an) ___________ bonding jumper is used to establish the connection between the grounded circuit conductor and the equipment grounding conductor at the service
main **see article 100 and definition**
High voltage conductors in tunnels shall be listed in
metal conduits metal raceways MC type cable (any of the above) **refer to section 110.53**
The control device of habitable room lighting outlets in dwelling units shall be located
near an entrance to the room on a wall **refer to section 210.70(A)(1)**
If the ungrounded supply conductors are larger than 1100 kcmil copper, the system bonding jumper (also copper) must have an area _________ of the area of the largest ungrounded supply conductors?
not less than 12-1/2% **refer table 250.102(C)(1)**
Service-entrance conductors shall have an ampacity of _____________.
not less than the maximum load to be served. **refer to section 230.42**
Section 110.34 - Work Space and Guarding covers the working space requirements for installations that are rated
over 1000 volts, nominal This is where Parts come into play. When we find section 110.34 we need to start flipping the book pages back until we run onto the first Part title. Doing that we will find that section 110.34 falls under part 3. Over 1000 Volts, Nominal.
Where a single equipment grounding conductor is run with multiple circuits in the same raceway, it shall be sized for
the largest overcurrent device protecting conductors in the raceway. **section 250.122(C)**
Which of the following methods are permitted for the connection of grounding and bonding conductors to the equipment?
thread forming machine screws that engage not less than two threads in the enclosures. **see section 250.8(A)**
Ground detectors shall be installed on ___________ alternating-current systems operating at 600 volts.
ungrounded. **section 250.21(B)(1)**
is the splicing of the direct buried service conductors allowed?
yes, if the splice is listed for such use **refer 230.33 first. this section discusses splicing of the service conductors and provides refs. to sections 110.14, 300.5 (E), 300.13, and 300.15. 300.5(E), stating that, "Direct-buried conductors or cables shall be permitted to be spliced or tapped without the use of splice boxes. The splices or taps shall be made in accordance with 110.14(B)."**
