Articles 220-230 Question Bank With Answers
The minimum clearance for overhead service conductors not exceeding 600V that pass over commercial areas subject to truck traffic is _____ ft.
18
The service disconnecting means rated 1,000V or less shall be marked to identify it as being suitable for use as service equipment and shall be _____.
230.66 Marking. Service equipment rated at 1000 volts or less shall be marked to identify it as being suitable for use as service equipment. All service equipment shall be listed or field labeled. Individual meter socket enclosures shall not be considered service equipment but shall be listed and rated for the voltage and ampacity of the service. 230.70(C) Suitable for Use. Each service disconnecting means shall be suitable for the prevailing conditions. Service equipment installed in hazardous (classified) locations shall comply with the requirements of Articles 500 through 517.
The minimum clearance for overhead feeder conductors that pass over track rails of railroads is _____ ft.
24.5
Underground service conductors shall be protected from damage in accordance with _____ including minimum cover requirements.
300.5
Service conductors installed as unjacketed multiconductor cable shall have a minimum clearance of _____ ft from windows that are designed to be opened, doors, porches, balconies, ladders, stairs, fire escapes, or similar locations.
3ft
The vertical clearance of final spans of overhead service conductors above, or within _____ ft measured horizontally of platforms, projections, or surfaces that will permit personal contact shall be maintained in accordance with 230.24(B).
3ft
Overhead service conductors installed over roofs shall have a vertical clearance of not less than _____ ft above the roof surface, unless a lesser distance is permitted by an exception.
8
Underground copper service conductors shall not be smaller than _____ AWG copper.
8
Overhead feeder conductors installed over roofs shall have a vertical clearance of not less than _____ above the roof surface, unless otherwise permitted by an exception.
8 ft 6in
Raceways on exteriors of buildings or other structures shall be arranged to drain and shall be _____ for use in wet locations.
Approved or listed
Raceways entering from outside shall be sealed with a product identified for use with the _____ insulation.
Cable or conductor
Additional services shall be permitted for different voltages, frequencies, or phases, or for different uses, such as for _____.
Different rate schedules
Grounding electrode conductors or supply side bonding jumpers or conductors shall not be permitted within raceways containing service conductors
False
Overhead service conductors or service equipment can be supported to hardwood trees.
False
Where fuses are used as the service overcurrent device, the disconnecting means shall be located ahead of the load side of the fuses in accord-ance with 230.91.
False
As defined by 230.95, the rating of the service disconnect shall be considered to be the rating of the largest _____ that can be installed or the highest continuous current trip setting for which the actual overcurrent device installed in a circuit breaker is rated or can be adjusted.
Fuse
In a multisection switchboard or switchgear, disconnects for the grounded conductor shall be permitted to be in any section of the switchboard or switchgear, if the switchboard or switchgear section is marked to indicate a _____ conductor disconnect is located within.
Grounded
The two to six disconnects for a disconnecting means for a building supplied by a feeder shall be _____.
Grouped
When the service contains two to six service disconnecting means, they shall be _____.
Grouped
Meter sockets supplied by and under the exclusive control of an electric utility shall not be required to be _____ in accordance with 230.66.
Listed
Each service disconnecting means shall be permanently _____ to identify it as a service disconnect.
Marked
Service conductors passing over a roof shall be securely supported by substantial structures, and for a grounded system, where the substantial structure is _____, it shall be bonded by means of a bonding jumper and listed connector to the grounded overhead service conductor.
Metal
The service disconnecting means shall plainly indicate whether it is in the _____ position.
Open or Closed
The disconnecting means for a building supplied by a feeder shall plainly indicate whether it is in the _____ position.
Open or closed
On a three phase, 4 wire, delta connected service where the midpoint of one phase winding is grounded, the service conductor 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, at each termination or junction point.
Orange
Vegetation such as trees shall not be used for support of _____.
Overhead conductor spans
When the service disconnecting means is a power operated switch or circuit breaker, it shall be able to be opened by hand in the event of a _____.
Power Supply Failure
When the disconnecting means for a building supplied by a feeder is a power operable switch or circuit breaker, it shall be able to be opened by hand in the event of a _____.
Power failure
Where documented safe switching procedures are established and maintained and the installation is monitored by _____ individuals, the disconnecting means for a building supplied by a feeder can be located elsewhere on the premises.
Qualified
The disconnecting means for a building supplied by a feeder shall be installed at a(n) _____ location.
Readily Accessible
The requirement to maintain a 3 foot vertical clearance from the edge of a roof does not apply to the final conductor span where the service drop is attached to _____.
The side of a building
A meter disconnect switch located ahead of service equipment shall have a short circuit current rating equal to or greater than the available short circuit current and be capable of interrupting the load served.
True
A one family dwelling unit and its accessory structure(s) shall be permitted to have one set of service entrance conductors run to each structure from a single service drop, set of overhead service conductors, set of underground service conductors, or service lateral.
True
One set of service entrance conductors connected to the supply side of the normal service disconnecting means shall be permitted to supply standby power systems, fire pump equipment, and fire and sprinkler alarms covered by 230.82(5).
True
Outside wiring shall not be installed beneath openings through which materials may be moved, and shall not be installed where they will obstruct entrance to these buildings' openings.
True
Service conductors installed in overhead masts on the outside surface of the building traveling through the eave, but not the wall, of that building are considered to be outside of the building.
True
Underground service entrance conductors shall be protected against physical damage.
True (In accordance with 300.5)
The 3 VA per square foot general lighting load for dwelling units does not include _____.
all
A building or structure shall be supplied by a maximum of _____ service(s), unless specifically permitted otherwise.
one
Each service disconnecting means shall be suitable for _____.
the prevailing conditions
The requirement for maintaining a 3 foot vertical clearance from the edge of the roof shall not apply to the final feeder conductor span where the conductors are attached to _____.
the side of a building
Service entrance and overhead service conductors shall be arranged so that _____ will not enter the service raceway or equipment.
water
When calculations in Article 220 result in a fraction of an ampere that is less than _____, such fractions can be dropped.
.5
A building or structure shall be supplied by a maximum of _____ feeder(s) or branch circuit(s), unless specifically permitted otherwise.
1
Where a building is designed and constructed to comply with an energy code adopted by the local authority and specifying an overall lighting density of less than 1.20 VA per 1.20 sq ft, the unit lighting loads in Table 220.12 for office and bank areas within the building shall be permitted to be reduced by _____ VA per sq ft.
1
Individual open conductors and cables, other than service entrance cables, shall not be installed within _____ ft of grade level or where exposed to physical damage.
10
The minimum point of attachment of overhead service conductors to a building shall not be less than _____ ft above finished grade.
10
Service entrance conductors can be spliced or tapped by clamped or bolted connections at any time as long as _____.
230.46 Spliced Conductors. Service-entrance conductors shall be permitted to be spliced or tapped in accordance with 110.14, 300.5(E), 300.13, and 300.15.
Conductors are considered outside a building when they are installed _____.
230.6 Conductors Considered Outside the Building. Conductors shall be considered outside of a building or other structure under any of the following conditions: Serving Utility (1) Where installed under not less than 50 mm (2 in.) of concrete beneath a building or other structure (2) Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 50 mm (2 in.) thick (3) Where installed in any vault that meets the construction requirements of Article 450, Part III (4) Where installed in conduit and under not less than 450 mm (18 in.) of earth beneath a building or other structure (5) Where installed within rigid metal conduit (Type RMC) or intermediate metal conduit (Type IMC) used to accommodate the clearance requirements in 230.24 and routed directly through an eave but not a wall of a build‐ ing
Individual meter socket enclosures shall not be considered service equipment but shall be _____ for the voltage and ampacity of the service.
Listed and rated
In a multiple occupancy building where electric service and electrical maintenance are provided by the building management under continuous building management supervision, the service disconnecting means can be accessible to authorized _____ only.
Management personnel
A service disconnecting means shall not be installed in bathrooms.
True
Cable trays used to support service entrance conductors shall contain only service entrance conductors _____.
and shall be limited to the following methods: (1) Type SE cable (2) Type MC cable (3) Type MI cable (4) Type IGS cable (5) Single conductors 1/0 and larger that are listed for use in cable tray
Overhead feeder and/or branch circuit conductors shall not be attached to a mast where the connection is _____ a weatherhead or the end of the conduit and a coupling where the coupling is located above the last point of securement to the building or other structure, or where the cou-pling is located above the building or other structure.
between
The general requirement for each service drop, set of overhead service conductors, set of underground service conductors, or service lateral is that it shall supply _____ set(s) of service entrance conductors.
only one
The additional service disconnecting means for fire pumps, emergency systems, legally required standby, or optional standby services, shall be installed remote from the one to six service disconnecting means for normal service to minimize the possibility of _____ interruption of supply.
simultaneous
There shall be no more than _____ disconnects installed for each service or for each set of service entrance conductors as permitted in 230.2 and 230.40.
six
There shall be no more than _____ switches or circuit breakers to serve as the disconnecting means for a building supplied by a feeder.
six
Overhead service conductors shall have a horizontal clearance of not less than _____ ft from a pool.
10 ft
The minimum clearance for overhead feeder conductors not exceeding 1,000V that pass over commercial areas subject to truck traffic is _____ ft.
18
For other than dwelling occupancies, banks, or office buildings, each receptacle outlet shall be calculated at not less than _____ VA.
180
If a set of 120/240V overhead feeder conductors terminates at a through the roof raceway or approved support, with not more than 6 ft of these conductors, 4 ft horizontally, passing over the roof overhang, the minimum clearance above the roof for these conductors is not less than _____.
18in
If a set of 120/240V overhead service conductors terminate at a through the roof raceway or approved support, with less than 6 ft of these conductors passing over the roof overhang, the minimum clearance above the roof for these service conductors shall be _____.
18in
The vertical clearance of final spans of overhead conductors above or within _____ ft measured horizontally of platforms, projections, or surfaces that will permit personal contact shall be maintained in accordance with 225.18.
3
For installations consisting of not more than two 2 wire branch circuits, the building disconnecting means shall have a rating of not less than _____.
30 amperes
The minimum size service drop conductor permitted is _____ AWG copper or _____ AWG aluminum or copper clad aluminum.
8,6
Additional services shall be permitted for a single building or other structure sufficiently large to make two or more services necessary if permitted by _____.
Special permission
The point of attachment of overhead premises wiring to a building shall in no case be less than _____ ft above finished grade.
10
Open individual conductors shall not be smaller than _____ AWG copper for spans up to 50 ft in length and _____ AWG copper for a longer span, unless supported by a messenger wire.
10,8
Ground fault protection of equipment shall be provided for solidly grounded wye electrical services of more than 150 volts to ground, but not exceeding 1,000V phase to phase for each service disconnecting means rated _____ or more.
1000A
Overhead feeder conductors shall have a minimum _____ ft vertical clearance over residential property and driveways, as well as those commercial areas not subject to truck traffic, where the voltage does not exceed 300 volts to ground.
12
A building disconnecting means that supplies only limited loads of a single branch circuit shall have a rating of not less than _____.
15 amperes
A service disconnecting means shall be installed at a(n) _____ location.
Readily accessible location
Overhead service entrance cables shall be equipped with a _____.
Service Head
In a multiple occupancy building, each occupant shall have access to the occupant's _____.
Supply disconnecting means
Where a mast is used for overhead branch circuit or feeder conductor support, it shall have adequate strength or be supported by braces or guys to safely withstand the strain imposed by the conductors.
T
Overhead service conductors shall have a minimum of _____ ft vertical clearance from final grade over residential property and driveways, as well as over commercial areas not subject to truck traffic where the voltage does not exceed 300 volts to ground.
12
Underground service conductors that supply power to limited loads of a single branch circuit shall not be smaller than _____.
12 AWG copper or 10AWG aluminum or copper-clad aluminum
For installations that supply only limited loads of a single branch circuit, the service disconnecting means shall have a rating not less than _____.
15 amperes
Service entrance cables mounted in contact with a building shall be supported at intervals not exceeding _____.
15ft (4.5m)
Wiring methods permitted for service entrance conductors include _____.
230.43 Wiring Methods for 1000 Volts, Nominal, or Less. Service-entrance conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and shall be limited to the following methods: (1) Open wiring on insulators (2) Type IGS cable (3) Rigid metal conduit (RMC) (4) Intermediate metal conduit (IMC) (5) Electrical metallic tubing (EMT) (6) Electrical nonmetallic tubing (7) Service-entrance cables (8) Wireways (9) Busways (10) Auxiliary gutters (11) Rigid polyvinyl chloride conduit (PVC) (12) Cablebus (13) Type MC cable (14) Mineral-insulated, metal-sheathed cable, Type MI (15) Flexible metal conduit (FMC) not over 1.8 m (6 ft) long or liquidtight flexible metal conduit (LFMC) not over 1.8 m (6 ft) long between a raceway, or between a race‐ way and service equipment, with a supply-side bonding jumper routed with the flexible metal conduit (FMC) or the liquidtight flexible metal conduit (LFMC) according to the provisions of 250.102(A), (B), (C), and (E) (16) Liquidtight flexible nonmetallic conduit (LFNC) (17) High density polyethylene conduit (HDPE) (18) Nonmetallic underground conduit with conductors (NUCC) (19) Reinforced thermosetting resin conduit (RTRC)
For installations consisting of not more than two 2 wire branch circuits, the service disconnecting means shall have a rating of not less than _____.
30 amperes
Where fixed multioutlet assemblies are used in other than dwelling units or the guest rooms of hotels or motels, each _____ or fraction thereof of each separate and continuous length shall be considered as one outlet of not less than 180 VA where appliances are unlikely to be used simultaneously.
5 ft
Service entrance cables which are not installed underground, where subject to physical damage, shall be protected by _____.
All other service-entrance conductors, other than underground service entrance conductors, shall be protected against physical damage as specified in 230.50(B)(1) or (B)(2). 230.50(B)(1) Service-Entrance Cables. Service-entrance cables, where subject to physical damage, shall be protected by any of the following: (1) Rigid metal conduit (RMC) (2) Intermediate metal conduit (IMC) (3) Schedule 80 PVC conduit (4) Electrical metallic tubing (EMT) (5) Reinforced thermosetting resin conduit (RTRC) (6) Other approved means 230.50(B)(2) Other Than Service-Entrance Cables. Individual open conductors and cables, other than service-entrance cables, shall not be installed within 3.0 m (10 ft) of grade level or where exposed to physical damage. Exception: Type MI and Type MC cable shall be permitted within 3.0 m (10 ft) of grade level where not exposed to physical damage or where protected in accordance with 300.5(D).
Electrical equipment shall not be connected to the supply side of the service disconnecting means, except for a few specific exceptions such as _____.
Only the following equipment shall be permitted to be connected to the supply side of the service disconnecting means: (1) Cable limiters or other current-limiting devices. (2) Meters and meter sockets nominally rated not in excess of 1000 volts, if all metal housings and service enclosures are grounded in accordance with Part VII and bonded in accordance with Part V of Article 250. (3) Meter disconnect switches nominally rated not in excess of 1000 V that have a short-circuit current rating equal to or greater than the available short-circuit current, if all metal housings and service enclosures are grounded in accordance with Part VII and bonded in accordance with Part V of Article 250. A meter disconnect switch shall be capable of interrupting the load served. A meter discon‐ nect shall be legibly field marked on its exterior in a manner suitable for the environment as follows: METER DISCONNECT NOT SERVICE EQUIPMENT (4) Instrument transformers (current and voltage), impe‐ dance shunts, load management devices, surge arresters, and Type 1 surge-protective devices. (5) Taps used only to supply load management devices, circuits for standby power systems, fire pump equipment, and fire and sprinkler alarms, if provided with service equipment and installed in accordance with require‐ ments for service-entrance conductors. (6) Solar photovoltaic systems, fuel cell systems, wind electric systems, energy storage systems, or interconnected elec‐ tric power production sources. (7) Control circuits for power-operable service disconnecting means, if suitable overcurrent protection and disconnect‐ ing means are provided. (8) Ground-fault protection systems or Type 2 surge- protective devices, where installed as part of listed equip‐ ment, if suitable overcurrent protection and disconnecting means are provided. (9) Connections used only to supply listed communications equipment under the exclusive control of the serving electric utility, if suitable overcurrent protection and disconnecting means are provided. For installations of equipment by the serving electric utility, a disconnecting means is not required if the supply is installed as part of a meter socket, such that access can only be gained with the meter removed.
If the voltage between overhead service conductors does not exceed 300V and the roof area is guarded or isolated, a reduction in clearance to 3 ft is permitted.
True
Service conductors shall not be installed beneath openings through which materials may be moved and shall not be installed where they will obstruct entrance to these buildings' openings.
True
Solar photovoltaic systems, fuel cell systems, wind electric systems, energy storage systems, or interconnected electric power production sources are permitted to be connected to the supply side of the service disconnecting means.
True
The 3 VA per square foot general lighting load for dwelling units includes general use receptacles and lighting outlets.
True
The type of disconnecting means specified in 225.31 shall be comprised of a circuit breaker, molded case switch, general use switch, snap switch, or other approved means.
True
Two family dwellings, multifamily dwellings, and multiple occupancy buildings shall be permitted to have one set of service entrance conductors to supply branch circuits for public or common areas.
True
Where a building or structure is supplied by more than one service, a permanent plaque or directory shall be installed at each service disconnect location denoting all other services supplying that building or structure and the area served by each.
True
Where a remote control device actuates the service disconnecting means, the service disconnecting means shall still be at a readily accessible location either outside the building or structure, or nearest the point of entry of the service conductors.
True
Where a service raceway enters a building or structure from a(n) _____, it shall be sealed in accordance with 300.5(G).
Underground distribution system
Each _____ service conductor shall have overload protection.
Ungrounded
Service heads on raceways or service entrance cables and goosenecks in service entrance cables shall be located _____ the point of attachment, unless impracticable.
above
Underground raceways entering a _____ from outside shall be sealed.
building or structure
A device comprised of _____ or more receptacles shall be calculated at not less than 90 VA per receptacle.
four
Where conduits are used as service masts, hubs shall be _____ for use with service entrance equipment.
identified
In a multiple occupancy building, each occupant shall have access to his or her own _____.
supply disconnecting means
