Journeyman Electrician
Receptacles supplying power to freestanding-type office furnishings shall be located NOT more than _____ from the furnishing that is connected to it.
1 foot
Surface-mounted incandescent luminaires installed on the wall above the door or on the ceiling of a clothes closet shall have a clearance of at LEAST ____ inches between the luminaire and the nearest point of closet storage space.
12
In regard to new outdoor installations of permanently installed swimming pools, luminaires installed above the pool or within 5 feet horizontally from the inside wall of the pool shall be installed at a height NOT less than _____ above the maximum water level of the pool.
12 feet
Exposed nonmetallic surface extensions shall be permitted to run in any direction from an existing outlet, but NOT within _____ from the floor.
2 inches
Raceways approved for burial only where concrete encased shall require a concrete envelope NOT less than _____ thick.
2 inches
The MINIMUM clearance above a diving platform of a swimming pool and 120/240-volt, single-phase, messenger supported, overhead service-drop conductors is _____.
14 1/2 feet
The MAXIMUM operating temperature for thermoplastic-covered solid fixture wire, Type TFF, is _____.
140ºF
Determine the conductor ampacity given the following related information: · conductors are size 500 kcmil copper · conductor insulation is THWN · eight (8) current-carrying conductors are in the raceway · ambient temperature is 125°F · conduit length is 75 feet · installation is a wet location
178.2 amperes
Receptacle outlets connected to a branch circuit rated for 30 amperes are permitted to have an ampere rating of _____.
30 amperes only
Given: An AC service is supplied with four (4) parallel sets of size 500 kcmil aluminium conductors. What is the MINIMUM size copper grounding electrode conductor required when connected to the concrete-encased building steel used as the grounding electrode system? Consider the grounding electrode conductor doesn't connect to another type of electrode that requires a larger size conductor.
4 AWG
The NEC® requires the MAXIMUM length permitted for a flexible cord supplying a 208-volt, single-phase, room air-conditioner to be _____.
6 feet
When branch-circuit conductors supplying a luminaire are contained inside a ballast compartment and they are within 3 inches of the ballast, the conductors shall have a temperature rating of at LEAST _____.
90°C
Where Type UF cable is used as a substitute wiring method for Type NM cable, the conductor insulation shall be rated _____.
90°C
Which of the following listed conductor insulations have a greater temperature rating when used in a dry location compared to when used in a wet location?
THHW
In general, which of the following receptacle outlets in a commercial kitchen are required by the NEC® to be GFCI protected?
All 125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground, and 50 amperes or less
An approved method of protection for equipment installed in Class I, Zone 0, hazardous locations is _____.
encapsulation
Where the outer sheath of Type MI cable is made of steel _____.
a separate equipment grounding conductor shall be provided
For the purpose of calculating the general lighting load for a dwelling unit, the floor area should include all of the following EXCEPT _____.
an open porch not adaptable for future use
An aluminum grounding electrode shall _____.
be prohibited
Class II locations are those that are hazardous (classified) because of the presence of _____.
combustible dust
When installed on the service of a building or structure, a Type 2 SPD shall be connected _____.
on the load side of the service disconnect overcurrent device
Emergency controls for unattended self-service motor fuel-dispensing facilities require one emergency control to be located between 20 feet and 100 feet of the fuel dispensers. The additional emergency control shall be _____.
readily accessible to each group of motor fuel dispensers on an individual island
When a service disconnecting means consists of two or three single-pole switches or circuit breakers capable of individual operation, installed in a common panel board enclosure and supplying multiwire circuits, this method of installation is _____.
in violation of the NEC® rules
Type NM cable is NOT permitted for use _____.
in wet locations
Nonmetallic sheathed cable is permitted to be used _____.
in multi-family dwellings of Type III, IV, and V construction
In dwelling units, the receptacle outlet provided for a built-in dishwasher shall be located __________.
in the space adjacent to the space occupied by the dishwasher
All 15- and 20-ampere, 125-volt and 250-volt, straight-blade type receptacles installed in a wet location shall be listed as _____ type.
weather-resistant
The interior of enclosures or raceways installed underground shall be considered to be a _____.
wet location
Determine the MINIMUM trade size electrical metallic tubing (EMT) required to enclose eight (8) size 6 AWG copper conductors with THHW insulation, where installed in a 60 foot conduit run.
1 1/4
For enclosing a mobile home supply cord, what is the MAXIMUM trade size conduit permitted between the branch-circuit panelboard of a mobile home and the underside of a mobile home floor?
1 1/4 inches
For other than one-family dwellings, spas and hot tubs are required to have a clearly labeled emergency shutoff or control switch provided. This switch shall be installed at a point readily accessible to the users and NOT less than _____ feet away and within sight of the spa or hot tub.
5
When grounding the structural reinforcing steel of a swimming pool, what is the SMALLEST size grounding conductor permitted for this installation?
8 AWG
Where sizes 1/0 AWG through 4/0 AWG single conductor cables are installed in a ladder type cable tray, the MAXIMUM allowable rung spacing for the ladder cable tray shall be _____.
9 inches
Which of the following listed cables has an overall covering that is fungus resistant?
Type NMC
In regard to solar photovoltaic systems, isolating devices or equipment disconnecting means shall be installed in circuits connected to equipment at a location within the equipment, or within _____ sight of the equipment.
10 feet
When exceptions are not a consideration, all 3-phase, 277/480 volt, wye-connected electrical services require ground-fault protection for each service disconnecting means when rated at LEAST _____ amperes or more.
1000
In Class II, Division 1, hazardous locations, where pendant mounted luminaires are suspended by rigid metal conduit (RMC) and a means for flexibility is not provided, the RMC stem shall have a length of NOT more than _____.
12 inches
Where exceptions are not to be applied, liquid tight flexible metal conduit (LFMC) shall be securely fastened within at LEAST_____ of each box, cabinet, or other conduit termination.
12 inches
Determine the ampacity of a size 1/0 AWG THW copper current-carrying conductor installed in a common raceway with three (3) other current-carrying conductors of the same size. Ambient temperature is 86°F.
120 amperes
Class 3 single-conductors, used as other wiring within buildings, shall NOT be smaller than _____ and shall be Type CL3.
18 AWG
Ten (10) copper THW conductors are to be installed in a 20-foot length of intermediate metal conduit (IMC): five (5) size 1 AWG and five (5) size 3 AWG. What is the MINIMUM allowable trade size IMC required to contain these conductors?
2 1/2 inches
The NEC® considers the area around the outdoor motor fuel dispensing pumps at a motor fuel service station to be a hazardous location. This area extends a height of 18 inches above grade, and up to a distance from the enclosure of the fuel dispensing pump of _____ feet.
20
Where an office building has a 208Y/120-volt, three-phase service with a balanced net computed load of 90 kVA, what is the approximate current each ungrounded (phase) conductor carries at full-load?
250 amperes
A plate-type grounding electrode shall be installed below the surface of the earth NOT less than _____.
30 inches
When driving a ground rod and solid rock is encountered, the ground rod is permitted to be buried in a trench that is at LEAST _____ deep.
30 inches
For Class III equipment that is not subject to overloading, the MAXIMUM surface temperature under operating conditions shall NOT exceed _____.
329 Degrees F
Determine the MAXIMUM number of size 14 AWG THHN conductors permitted to be installed in a trade size 3/8 inch flexible metal conduit (FMC) that contains a bare size 14 AWG grounding conductor when the FMC has external fittings.
4
Given: An existing metal junction box has a volume of 27 cubic inches and contains a total of six (6) size 12 AWG wires. Additional wires of size 10 AWG need to be added in the box. No grounding conductors, devices, or fittings are contained in the box. What is the MAXIMUM number of size 10 AWG conductors that may be added to this box?
5
When ambient temperature is not a factor, a size 8 AWG single copper conductor with Type FEPB insulation, installed in free air, has an ampacity (current-carrying capacity) of _____ amperes.
80
Class _____ locations are those that are hazardous because of the presence of easily ignitable fibers or where materials producing combustible flyings are handled.
III
When determining the required ampacity of the branch-circuit conductors to supply an AC, three-phase, continuous-duty motor, current values of the motor given on _____ shall be used.
Table 430.250 of the NEC®
Which of the following wiring methods is/are approved for use for fixed wiring in an area above Class I locations in a commercial repair garage?
Type MC cable Type AC cable Type MI cable
Disregarding exceptions, all of the following wiring methods listed are permitted to be used as a feeder for temporary wiring on a construction site EXCEPT _____.
Type PD cord
As a general rule, when a size 4 AWG or larger insulated conductor enters a panelboard, cabinet, or enclosure, which of the following must be provided?
an insulated bushing
When a raceway is run through the wall from the interior to the exterior of a building, the raceway shall _____.
be sealed with an approved material
The continuity of the equipment grounding conductor system used to reduce electrical shock hazards for portable electrical carnival equipment shall be verified ____.
each time the equipment is connected
Given: A size 14 AWG branch-circuit conductor protected by a 15-ampere rated circuit breaker is to supply three (3) 20-ampere rated duplex receptacles. This branch circuit _____.
is not in compliance with the NEC® because the receptacle outlets have a 20-ampere rating
When an overcurrent protective device for a surge-protective device is located at the service location, it _____.
is not to be counted as a service disconnect
When sizing time-delay Class CC fuses for motor branch-circuit, short-circuit, and ground-fault protection, they are to be sized at the same value as _____.
non-time-delay fuses
Mandatory rules of the NEC® are those that identify actions that are specifically required or prohibited, and are characterized by the use of the terms _____.
shall or shall not
Where installed in wet locations, all 15- and 20-ampere, 125-volt and 250-volt straight blade-type receptacles shall be listed as the _____ type.
weather-resistant
An installation of 40 feet of electrical metallic tubing (EMT) will contain the following conductors: three (3) size 2 AWG with THWN insulation four (4) size 6 AWG with THWN insulation three (3) size 10 AWG with THWN insulation This installation requires a MINIMUM trade size _____ EMT.
1 1/2 inch
Surge-protective devices (SPDs) shall NOT be installed on circuits exceeding _____ volts.
1,000
In closed construction of a manufactured building, what is the MAXIMUM size cable that may be used without additional support between boxes?
10 AWG
Apply the general method of calculation for dwelling units, and determine the demand load, in kW, on the ungrounded service-entrance conductors for a single 20,800 watt electric range.
11.6 kW
Where a motor has a temperature rise of 46°C indicated on the nameplate, for the purpose of selecting the overload device, this device shall be selected to trip at NO more than _______ of the motor full-load current rating. (Assume that the value selected will enable the motor to start without tripping the overload device and modification of this value is not necessary.)
115 percent
Given: Type UF cable is to be used as direct buried residential branch circuits of 120 volts. The conductors are GFCI protected and overcurrent protection is rated 20 amperes; the cables do not cross under any driveways or concrete. What is the MINIMUM permitted burial depth of the cable?
12 inches
Disregarding exceptions, where a feeder supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous loads PLUS _____ of the continuous loads.
125%
Lampholders shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in EXCESS of ______.
194ºF
What MINIMUM size 75ºC copper branch-circuit conductors are required to supply a continuous-duty, 208-volt, 3-phase, 30 horsepower motor with a nameplate ampere rating of 80 amperes?
2 AWG
What is the full-load current rating on the secondary side terminals of a 75 kVA, three-phase transformer having a 277/480 volt primary and a 208Y/120 volt secondary?
208 amperes
For other than one- and two-family dwellings, at least one 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlet shall be installed at an accessible location within at LEAST _____ of the indoor installed electrical service equipment.
25 feet
Given: An office building contains two hundred (200) general-purpose, 125 volt duplex receptacle outlets rated at 15 amperes each. What is the total connected load, in VA, for the receptacles?
36,000 VA
In general, a general-use fused switch used as a disconnecting means for a 25 hp, 480-volt, three-phase AC motor with a FLA of 32 amperes indicated on the nameplate must have an ampere rating of at LEAST _____.
39 amperes
Given: An unbroken length of size 12 AWG conductor is looped inside a junction box so that there is more than 12 inches of free conductor. The conductor is not spliced and does not terminate on a device. What volume, in cubic inches, must be counted for the looped conductor?
4.50 cubic inches
When a size 8/3 AWG with ground copper NM cable is installed in the attic of a dwelling unit where the ambient temperature reaches 130ºF during the summer months, the conductors have an ampacity of _____.
40.0 amperes
Standard electrical trade size 2-inch rigid polyvinyl chloride conduit (PVC) shall be supported at LEAST every _____.
5 feet
When armored cable (AC) is installed in thermal insulation, the ampacity of the cable shall NOT exceed that of _____ conductors.
60°C
Where exceptions are not to be taken into consideration, where a feeder supplies a continuous lighting load of 39 amperes and a continuous-duty motor load of 24 amperes, the feeder must have an ampacity of at LEAST _____.
79 amperes
Each patient bed location in the general care (Category 2) spaces of a hospital or similar health care facility shall be provided with a MINIMUM of ______ 125-volt, single-phase, 15- or 20-ampere listed "hospital grade" receptacles.
8
All wiring installed in or under an aircraft hangar floor shall comply with the requirements for _____ locations.
Class I, Division I
Where a single 125-volt, single-phase, 20-ampere receptacle outlet located in an attached garage of a dwelling unit is provided for a central vacuum assembly, the receptacle outlet is required to have _____.
GFCI protection
Class _____ hazardous locations are those in which flammable gases, flammable liquid-produced vapors, or combustible liquid-produced vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures.
I
Electrical equipment such as switchboards, panelboards, industrial control panels, and motor control centers that are located in commercial and industrial occupancies are required to be field marked to warn _______ of potential electric flash hazards.
Qualified persons
Which of the following listed flexible cords shall be permitted to be immersed in water in order to supply a permanently installed fountain located at an amusement park?
Type SOW
In regard to emergency and legally required standby systems, transfer switches shall be _____ and approved by the authority having jurisdiction.
automatic
Which of the following listed types of batteries is NOT permitted for use as a source of power for emergency systems?
automotive
Where a central vacuum assembly is located in a storage closet adjacent to the laundry room of a dwelling, accessible non-current-carrying metal parts, likely to be energized, of the assembly shall be ______.
connected to an equipment grounding conductor
The accessible portion of abandoned supply circuits and interconnecting cables located in an information technology equipment room shall be removed, UNLESS _____.
contained in a raceway
For indoor installations about switchboards and panelboards, the space equal to the width and depth of the equipment and extending from the floor to the ceiling to a height of 6 feet above the equipment or to the structural ceiling is known as the _____.
dedicated electrical space
When buried raceways pass under a driveway or an alley, the MINIMUM cover requirements _____.
do not change in regard to wiring methods used
n regard to artificially made bodies of water, liquidtight flexible metal conduit (LFMC) is a wiring method permitted for use for a feeder or branch circuit where flexibility is required; which of the following listed wiring methods is also approved for this use?
extra-hard usage portable power cable
Type AC cable shall be permitted _____.
for feeders
In an underground installed Schedule 40 PVC conduit system that consists of 50 feet in length between pulling points, what is the MAXIMUM number of bends this conduit run may have?
four 90° bends
In a health care facility, a patient bed location in a critical care (Category 1) space, is required to be provided with a MINIMUM of _____.
fourteen (14) single receptacles or seven (7) duplex receptacles
The NEC® requires all ground-fault circuit-interrupter (GFCI) devices to be installed _____.
in a readily accessible location
According to the National Electrical Code®, what are the three (3) separate mandatory branches of the hospital Type I essential emergency electrical system?
life safety branch, critical branch, and equipment branch
Which of the following circuits is prohibited for the grounded (neutral) conductor to be dependent on receptacle devices for continuity?
multi-wire circuits
Which of the following listed luminaires is NOT permitted for installations in clothes closets?
pendant luminaire
Electrical equipment such as distribution panelboards, motor controllers, and motor control centers that are located in other than dwelling units, and are likely to require examination, adjustment, servicing, or maintenance while energized, shall be field or factory marked to warn qualified persons of _____.
potential arc flash hazards
Which of the following listed wiring methods is NOT permitted in a ceiling space used as a return-air plenum?
rigid PVC conduit
Transfer equipment of optional standby systems shall be suitable for the intended use and designed and installed so as to prevent the inadvertent interconnection of _____ sources of supply in any operation of the transfer equipment.
primary and secondary input and output AC and DC
A neutral conductor is always _____.
the conductor connected to the neutral point of a system that is intended to carry current under normal conditions
In general, motor control circuits shall be arranged so that they will be disconnected from all sources of supply when _____.
the disconnecting means is in the open position
Which of the following grounding electrodes is NOT permitted to be used as an effective ground-fault current path?
the earth
Where an equipment room houses electrical equipment, the personnel doors intended for the entrance to and egress from the working space shall open in the direction of egress when _____.
the electrical equipment has a rating of at least 800 amperes or more
The short-circuit and ground-fault protective device protecting an air-conditioner motor-compressor branch-circuit shall have sufficient _____ to permit the motor-compressor and other motors to start and accelerate their loads.
time delay
For the purpose of determining conductor fill in a device box, a single-pole switch is counted as equal to _____ conductor(s), based on the largest conductor connected to the switch.
two
In guest rooms or guest suites of hotels and motels, and sleeping rooms in dormitories, at LEAST _____ general purpose receptacle(s) installed in the room is/are required to be readily accessible.
two
Where a small retail store to be constructed will have an area of 1,600 square feet, when exceptions are not a consideration, how many 15-ampere, 120-volt general lighting branch circuits are required for this installation?
two
Given: An equipment disconnecting means is mounted at a height of 6 feet above floor level on a remote wall in an aircraft storage and maintenance hangar. The disconnect switch is 10 feet horizontally from any aircraft fuel tanks. The disconnect switch is located in a/an _____ area.
unclassified
Liquid-tight flexible metallic conduit (LFMC) shall NOT be used _____.
where subject to physical damage
Storage batteries used as a source of power for emergency systems shall be of a suitable rating and capacity to supply and maintain the total load for at LEAST _____ without the voltage applied to the load falling below 87½ percent of normal.
1 1/2 hours
Luminaires installed under metal-corrugated sheet roofing decking shall be installed and supported so there is NOT less than _____ clearance from the lowest surface of the roof decking to the top of the luminaires.
1 1/2 in
Where an exposed outlet box is installed under metal-corrugated roof decking, a clearance of NOT less than _____ is to be maintained from the lowest surface of the roof decking to the top of the box.
1 1/2 inches
Neon sign equipment having an open circuit voltage exceeding how many volts shall NOT be installed in or on dwelling occupancies?
1,000 volts
When calculating the total load for a commercial building, what is the MINIMUM computed load, in volt-amps, required by the NEC® for a branch circuit supplying an exterior electric sign?
1,200 volt amperes
Which of the following is permitted for closing an unused circuit breaker opening in panelboards?
1. installation of a closure plate listed for the purpose by the manufacturer 2. Installation of a spare or unused circuit breaker that fills the opening and is listed for the panelboard 3. Installation of a closure plate or other device that fits securely and closes the opening
The internal depth of an outlet box used only to splice conductors to a luminaire and does not enclose devices or utilization equipment shall NOT be less than _____.
1/2 inch
In a health care facility, low-voltage electrical equipment that is likely to become energized and is frequently in contact with the bodies of patients shall operate on a voltage of _____ volts or less if the equipment is not approved as intrinsically safe, double-insulated, or moisture-resistant.
10
What is the MINIMUM size equipment grounding conductor required by the NEC® for a branch circuit protected by a 50-ampere rated circuit breaker?
10 AWG
What is the MINIMUM size equipment grounding conductor required for a 5 hp, 3-phase, 208-volt motor having 20-ampere rated overload protection and short-circuit overcurrent protection rated at 30 amperes?
10 AWG
In general, branch-circuit conductors supplying more than one motor shall have an ampacity of at LEAST _____ percent of the full-load current (FLC) rating of the highest rated motor in the group, and 100 percent of the FLC rating(s) of the other motor(s) in the group.
125
The rating of a branch circuit supplying a fixed, storage-type, electric water heater with a capacity of 120 gallons or less shall NOT be less than _____ percent of the full-load current of the water heater.
125
A 208-volt, 3-phase, 50 hp, squirrel-cage, continuous-duty, Design C, AC motor has a full-load running current of _____.
143 amperes
The MAXIMUM initial standard rating of the non-time-delay fuses for the branch-circuit, short-circuit, and ground-fault protection of a 1 hp, three-phase, 208-volt, squirrel-cage AC motor shall be _____ amperes.
15
What is the MINIMUM size equipment grounding conductor required by the NEC® for a branch circuit protected by a 50-ampere rated circuit breaker?
15 amperes
Information technology equipment shall be permitted to be connected to a branch circuit by a listed power-supply cord NOT more than _____ in length.
15 feet
Given: A small office building has a noncontinuous load of 12,200 VA and a continuous load of 16,200 VA. Determine the MINIMUM standard size fuses permitted to be used for overcurrent protection on the service disconnecting means. The electrical system is 120/240-volt, single-phase. Apply no exceptions.
150 amperes
Enclosures in a Class I, Division 1, location containing components that have arcing devices must have an approved conduit seal located within _________ inches of the enclosure, or as required by the enclosure marking, on each conduit run entering or leaving such enclosures.
18
Before demand factors are taken into consideration for commercial buildings, general purpose receptacle loads are to be computed at NOT less than _____ VA per single or duplex receptacle mounted on one yoke.
180
Determine the MAXIMUM number of size 1 AWG XHHW compact conductors permitted in a trade size 3-inch, Schedule 40, rigid PVC conduit that is 100 feet long.
21
Determine the MINIMUM size THW copper branch-circuit conductors required by the NEC® to supply a 3-phase, continuous-duty, AC motor that has a full-load current of 70 amperes. Assume all terminations to be rated for 75°C.
3 AWG
Where conduits enter a floor-standing switchboard, switchgear or panelboard at the bottom, the conduits including their end fittings, shall NOT rise more than _____ above the bottom of the enclosure.
3 inches
Grounding electrodes made of pipe or conduit shall NOT be smaller than _____ electrical trade size.
3/4
Each receptacle of dc plugging boxes in motion picture studios shall be rated at NOT less than _____.
30 amperes
In general, when feeder conductors of not over 600 volts supply a continuous load of 240 amperes, the overcurrent protection device protecting this circuit shall have a MINIMUM rating of _____.
300 amperes
Where a trade size ½-inch rigid metal conduit (RMC) is to be installed in a Class I location and a trade size ½-inch conduit seal is required, the MINIMUM thickness of the sealing compound shall NOT be less than _____.
5/8 inch
Type MI cable shall be supported and secured at intervals NOT exceeding _____ feet.
6
The MINIMUM height of headroom of working spaces above service equipment, switchboards and motor control centers shall be at LEAST_____ or the height of the equipment, whichever is greater.
6 feet 6 inches
When installing wiring for sensitive electronic equipment, the MAXIMUM voltage to ground is required to be __________ volts.
60
The MINIMUM rating for a service disconnecting means for a building, other than a one-family dwelling, consisting of three (3) 2-wire circuits shall be _____.
60 Amperes
Where an 80-ampere, 240-volt, single-phase load is located 200 feet from the panelboard and is supplied with size 3 AWG copper conductors with THHN/THWN insulation, what is the approximate voltage-drop on this circuit? (K = 12.9)
7.84 volts
When a metal wireway contains splices and taps, the conductors, splices, and taps shall NOT fill the wireway to more than _____ percent of its area at that point.
75
When a pull box contains conductors of size 4 AWG and larger and a straight pull of the conductors is to be made, the length of the box shall NOT be less than _____ times the trade diameter of the largest conduit entering the box.
8
Where an AC transformer arc welder has a 50 ampere-rated primary current and a 60 percent duty-cycle, what is the MINIMUM size 60°C rated copper conductors the NEC® requires to supply this welder?
8 AWG
Direct-buried conductors and cables emerging from grade shall be protected by raceways or enclosures up to a point of at LEAST _____ above finished grade.
8 feet
Given: You have determined a conductor has a computed allowable ampacity of 75 amperes. What is the MAXIMUM standard ampere rating of the overcurrent protection device the NEC® permits to protect this circuit? Assume this is not a motor circuit or part of a branch circuit supplying more than one receptacle.
80 amperes
Determine the ampacity of a size 3 AWG THHN copper conductor given the following related information: Three (3) conductors are in the conduit; two (2) conductors are current-carrying. The ambient temperature is 34°C. The equipment terminations are rated 60°C.
85.0 amperes
A surge-protective device (SPD) is a protective device for _____.
limiting transient voltage by diverting or limiting surge current