GDOT Section 924: Miscellaneous Electrical Materials

SECTION 924 — Miscellaneous Electrical Materials

924.1General Description

This section includes the requirements for the following miscellaneous electrical materials: • Ground rods—924.2.01 • Pull and Junction Boxes—924.2.02 • Breakaway Bases—924.2.03 • Fuses and fuse holders—924.2.04 • Surge Protective Devices and Lightning Arrestors—924.2.05 • Circuit breakers—924.2.06 • Photoelectric controls—924.2.07 • Magnetic contactors—924.2.08 • Service Entrance Caps (Weatherheads)—924.2.09 • Transformers—924.2.10 • Enclosures—924.2.11 • Service Disconnect Switch—924.2.12 924.1.01 Related References

A.Standard Specifications

General Provisions 101 through 150.

B.Referenced Documents

ASTM F883-13, Standard Performance Specification for Padlocks ASTM C857-16, Standard Practice for Minimum Structural Design Loading for Underground Precast Concrete Utility Structures ANSI C136.10, Locking-Type Photocontrol Devices and Mating Receptacles—Physical and Electrical Interchangeability and Testing ANSI/IEEE C62.41.2, Characterization of Surges in Low-Voltage (1000 V and Less) AC Power Circuits ANSI/SCTE 77 2017, Specifications for Underground Enclosure Integrity IEC EN 62561-2, Lightning Protection System Components IEEE C62.1-1989, Standard for Gapped Silicon-Carbide Surge Arresters for AC Power Circuits NEC Article 110.28 NEC Article 314.28, Pull and Junction Boxes and Conduit Bodies 1790

SECTION 924 — Miscellaneous Electrical Materials

Underwriter’s Laboratories (UL) Standards: UL 50, Standard for Enclosures for Electrical Equipment UL 98, Enclosed and Dead-Front Switches UL 248-4, Standard for Safety Low-Voltage Fuses – Part 4: Class CC Fuses UL 489, Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures UL 467, Standard for Grounding and Bonding Equipment UL 508, Standard for Industrial Control Equipment UL 514B, Conduit, Tubing, and Cable Fittings UL 773, Standard for Plug-In Locking Type Photocontrols for Use with Area Lighting UL 1066, Standard for Low-Voltage AC and DC Power Circuit Breakers Used in Enclosures UL 1332, Standard for Organic Coatings for Steel Enclosures for Outdoor Use Electrical Equipment UL 1449, Standard for Surge Protective Devices UL 2416, Standard for Audio/Video, Information and Communication Technology Equipment Cabinet, Enclosure and Rack Systems UL 5085-1, Low Voltage Transformers - Part 1: General Requirements

924.2Materials

Ensure that all electrical materials are approved by the Underwriter’s Laboratory or other acceptable testing agency. 924.2.01 Ground Rods

A.Requirements

1.Use ground rods that are 3/4 in. ± 1/16 in. (19 mm, ± 2 mm) diameter and 10 ft. (3.05 m) long, unless

otherwise shown in the Contract.

2.Ensure that the rods are copper bonded (copper clad) steel with a minimum coating of 10 mils according to

UL 467. Complies with IEC EN 62561-2

3.Nationally Recognized Testing Laboratory (NRTL) listed to UL 467 and must contain NRTL markings on

exposed end.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150. 1791

SECTION 924 — Miscellaneous Electrical Materials

924.2.02 Pull and Junction Boxes

A.Requirements

1.General Requirements for all Pull and Junction Boxes

a.Pull and junction boxes shall be sized appropriately to accommodate the cables necessary, only to 40%

capacity of the box’s internal capacity in accordance to NEC 314.28(A).

b.Concrete and Polymer pull boxes are utilized in at grade installations and used as locations to pull, or roll

cable. Splicing of service or branch circuit cable within pull boxes is not allowed.

c.Junction boxes are above grade boxes and utilized where conduit makes a transition from installation

type, conduit type or other transition. Proper splicing within above grade junction boxes is permitted.

2.Concrete Pull Boxes

a.Construct concrete boxes from Class A concrete and according to Section 500.

b.Provide cast iron, steel, or reinforced concrete covers with each pull or junction box according to the

Contract.

c.Ground the cast iron or steel covers to electrical junction or pull boxes according to the NEC.

d.Concrete pull boxes installed within 12 feet of active lanes shall be traffic rated and compliant with

AASHTO H-15 loading requirements, including the lid. For installations where heavy truck traffic is expected, AASHTO H-20 load rating shall be used.

3.Precast Pull Boxes

a.Precast boxes shall be certified and rated per ASTM C857-16, Standard Practice for Minimum Structural

Design Loading for Underground Precast Concrete Utility Structures, ASTM International, West Conshohocken, PA, 2016, www.astm.org. Boxes shall have the minimum rating specified in the Contract.

b.Precast boxes installed within 12 feet of active lanes shall be traffic rated and compliant with AASHTO H-

15 loading requirements. For installations where heavy truck traffic is expected, AASHTO H-20 load rating shall be used.

4.Fiberglass/Polymer Pull Boxes

a.Boxes shall meet or exceed Tier 22 requirements of ANSI/SCTE 77 2017, AMERICAN NATIONAL

STANDARD--Specifications for Underground Enclosure Integrity

b.Boxes installed within 12 feet of active lanes shall be traffic rated and compliant with AASHTO H-15

loading requirements. For installations where heavy truck traffic is expected, AASHTO H-20 load rating shall be used.

5.Metal Junction Boxes

a.Metal junction boxes shall be galvanized rigid steel, unless specifically approved by the Engineer, and

shall comply with NEC Article 314.28, Pull and Junction Boxes and Conduit Bodies.

b.Shall be listed to UL 50, Enclosures for Electrical Equipment, non-Environmental Consideration

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150. 1792

SECTION 924 — Miscellaneous Electrical Materials

924.2.03 Breakaway Bases

A.Requirements

1.Breakaway bases are only intended to be used on street light poles installed within clear zone and not

intended to be utilized on traffic signal, camera, ATMS or other poles that have electrical equipment.

2.In compliance with AASTHO, quick disconnect/breakaway fusing is required within all breakaway bases.

See Section 924.2.4.

3.Shall only be utilized as indicated in the Contract or as approved by the Engineer.

4.Shall have been evaluated using the AASHTO Loading Guide and MASH testing criteria requirements for the

application in which it is used, and the manufacturer must furnish a letter of eligibility for the device from the FHWA.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150 924.2.04 Fuses and Fuse Holders

A.Fuse Holders

1.Each fuse holder shall consist of a two-section unit designed to hold small-dimension cylindrical fuses of

the type UL Class CC or as required. Each section shall be permanently marked with line and load side designations and the unit shall have a water and vapor-tight seal rated IP67when the sections are joined. Two- pole fuse holders with setscrew terminals shall be used unless otherwise specified.

2.The terminals and the contacts in the fuse holder shall be made of tinned copper or other material

suitable for contacts as approved by the Engineer. The contacts shall be spring loaded or tulip style to exert contact pressure on mating parts. Fuse holders shall be rated for 30 A at 600 V at 167 °F (75 °C) operation.

3.Fuse holders shall have a molded neoprene rubber, or impact resistant polymer housing. Wires shall

attach to the fuse holder by a crimping operation, except that connection of No. 2 wires to breakaway fuse holder receptacles may be via a set screw connection. Each fuse holder shall be of a size proper for the wires to be attached. The assembly shall be provided with insulating boots as needed.

4.Phase to phase circuit applications shall be designed so that both phase conductors are disconnected at

the same time. Phase to neutral circuit applications shall be designed so that both phase and neutral conductors are disconnected at the same time. Blanks shall be used instead of fuses for the neutral conductor and they shall be clearly marked with white bands to designate a neutral plug.

5.The fuse holder shall be capable of disconnecting upon sufficient tension in the connected wires, as in a

pole knockdown. The fuse shall remain enclosed in the de-energized portion of the fuse holder upon disconnection. The fuse shall not be utilized as the disconnection means. Break-away style must readily disconnect from power in case of a pole knockdown and shall be compliant with AASHTO breakaway quick disconnect requirements. The breakaway feature shall consist of a receptacle permanently attached to the power line and a fuse holder with matching terminals. If a knockdown occurs, the parts shall separate, leaving the energized conductor recessed and unexposed. 1793

SECTION 924 — Miscellaneous Electrical Materials

B.Fuses

1.Fuses for installation within fuse holders for protection of luminaires shall be small-dimension, 1 1/2 in.

long x 13/32 in. dia. (38 mm x 10 mm), cylindrical fuses of the time-delay type. The fuses shall be rated for 600 V AC, Type FNQ time-delay fuses and meet the requirements of UL Standard 248-4. The fuses shall have a UL listed interrupting rating of not less than 10,000 rms symmetrical amperes at rated voltage. They shall be sized at 300 percent of the starting or operating current whichever is greater, but in no case greater than 50 percent of the branch circuit conductor ampacity.

2.Fuses shall be NRTL listed to UL 248-4 and be marked accordingly.

A.Acceptance

General Provisions 101 through 150.

B.Materials Warranty

General Provisions 101 through 150. 924.2.05 Surge Protective Devices and Lightning Arrestors Lightning Arrestors shall be located in the Controller Cabinet when the application calls for equipment to be powered from the secondary side of a step-down transformer. Each Luminaire shall have an internal primary lightning arrestor or surge protective device. See below for details.

A.Primary Surge Protective Device (SPD) (Luminaire)

1.The surge protector shall be labeled Type 2 in accordance with UL 1449.

2.The surge protector shall include a thermally protected transient voltage suppression circuit.

3.The surge protector shall be totally weatherproof.

4.The surge protector shall be rated for operation at the system voltage.

5.The surge protector shall provide protection for Line-Ground or Line-Neutral/Ground and Line-Line in

accordance with ANSI/IEEE C62.41.2 guidelines.

6.The surge protector shall have a high temperature, flameproof enclosure with a minimum of 85°C

maximum case temperature rating.

7.The surge protector shall be rated to withstand a surge current of 20,000 amperes using industry standard

8/20 μSec waveform and repetitive surges of 200 amperes for a minimum of 10,000 occurrences.

8.The surge protective device shall have a clamping voltage that is less than that of the surge protection

provided in the LED driver used in the luminaire, and a maximum continuous over voltage (MCOV) rating of at least 550V.

9.The surge protector response time shall be less than 50 nanoseconds.

10.The surge protector current drain(leakage) shall not exceed 100 microamperes.

11.The surge protector shall not allow holdover current or conduction to ground after the surge ends.

12.The surge protector shall be provided with an integral LED indicating light which shall be illuminated to

indicate proper function and protection for each line.

13.The device shall disconnect power to the luminaire upon failure of the device. Device failure is defined as

the inability of the device to provide its rated surge protection to the luminaire. 1794

SECTION 924 — Miscellaneous Electrical Materials

B.Secondary Surge Protector (Control Cabinet)

1.Secondary Surge Arrestors shall be a type 1 SPD, two pole units of the valve-type, consisting of a spark

gap structure and silicon carbide valve blocks.

2.The arrestors shall be 650 Volt, maximum rated, designed for the protection of 480-volt, single phase,

ungrounded secondary services. The arrestors shall meet all applicable ANSI, NEMA, IEEE, and OSHA

standards, Such as IEEE C62.1-1989 Standard for Gapped Silicon-Carbide Surge Arresters for

AC Power Circuits.

C.Fabrication

General Provisions 101 through 150.

D.Acceptance

General Provisions 101 through 150.

E.Materials Warranty

General Provisions 101 through 150.

924.2.06 Circuit Breakers

A.Requirements

1.Circuit breakers employed either as individual devices or as components of a panelboard shall be of the

manually-operated molded-case type with frame size, number of poles, current trip ratings and enclosures

as shown in the Contract.

2.Circuit breakers shall have a UL listed interrupting rating of not less than 65,000 rms symmetrical amperes at

rated circuit voltage.

3.Circuit Breakers shall have inverse-time thermal, and instantaneous magnetic overload trip elements. Multi-

pole breakers shall have trip elements on each pole connected to a common trip bar. The circuit breakers

shall be trip-free from the handle on overloads and short circuits. Automatic tripping shall be clearly

indicated by the handle position. The breakers shall be treated to resist fungus Circuit breakers shall

conform to adjacent breakers, be NRTL listed per UL 1066, conform to NEMA Standard AB 1, and meet

Federal Specifications W-C-375b.

4.Breakers shall have proper sized lugs for the cable used. Do not cut cable strands to attach to

circuit breakers.

5.Be enclosed in a lockable, weatherproof enclosure.

6.The number of branch circuit breakers shall be as indicated on the Control Cabinet detail drawing or as

indicated in the lighting system wiring diagram whichever is greater plus two spare circuit breakers.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Material Warranty

General Provisions 101 through 150. 1795

SECTION 924 — Miscellaneous Electrical Materials

924.2.07 Photoelectric Controls

A.Requirements

1.Have a suitable differential between turn-on and turn-off levels to prevent cycling at critical levels and a time

delay response to preclude nuisance tripping due to stray light.

2.Photo Electric Control Switches shall have a hermetically sealed silicon sensor cell with an NIR filter and rated

for 1,000 watts minimum load.

3.A fail-safe operating feature such as normally closed contacts shall be included so that the lighting circuits will

remain energized in the event the photo control components become inoperative.

4.Operating Light Levels, Turn-on: 1.5 FC, 1.5:1 Off/On Ratio These illumination settings shall be set by the

Manufacturer and maximum tolerances of ± 20% for the specified values shall be acceptable.

5.Photo Electric Control Switches shall comply with ANSI C136.10 Standard twist lock type design with high-

impact resistant plastic weatherproof housing. A locking type receptacle mounted in an impact resistant

housing with ¾ in. pipe thread suitable for conduit mounting shall be provided for installation as indicated on

the Standard Drawings or the Contract. Receptacles shall be impact resistant and withstand the impact of the

luminaire being dropped from a 3-foot height and the receptacle striking a concrete surface. It shall operate

on a supply voltage of 105-130 volts, 60 Hz AC, with an inrush rating of 120 amperes at 120 volts and be

NRTL listed to UL 773.

6.Contain built-in surge and lightning protection and an MOV rated at 320 joules minimum.

7.Have a rated life at full load of at least 5,000 on-off operations

8.Have relay contacts that are single-pole, single-throw (SPST), normally closed (NC)

9.Have dielectric strength of at least 5,000 volts between any current carrying part and metal mounting surface

Withstand an ambient temperature range of–65° to 158° F (–54° to 70° C)

10.Have a moisture proof housing about 2-1/4 in. (60 mm) high with a base diameter of less than

3-1/4 in. (85 mm)

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150. 1796

SECTION 924 — Miscellaneous Electrical Materials

924.2.08 Magnetic Contactors

A.Requirements

1.Lighting contactors, unless otherwise noted, shall be two-pole, line voltage and current rated contactors in

a lockable NEMA type 4x enclosure (per NEMA 250) as shown in the Contract or in the Standard Drawings.

The contactors shall meet the requirements of Underwriters’ Laboratories Standard UL 508.

2.Lighting contactors shall be of a single-coil, electrically operated, mechanically held type. Positive locking

shall be obtained without the use of hooks, latches or semi-permanent magnets.

3.Main contacts shall be double-break silver alloy or silver alloy-type, protected by arcing contacts. Contacts

shall be self-aligning and renewable from the front of the panel. Terminals shall be pressure wire connectors.

4.Each contactor shall be furnished complete with a 2-wire control relay for reversing the switch and breaking

the control circuit. The control solenoid and circuit shall be fused and wired for operation from a separate

120V, AC supply source unless otherwise specified. One set of spare contacts and 2 sets of spare fuses shall

be provided with each contactor.

5.Have proper lugs that are sized for the cable used. Do not cut cable strands to attach to contactor terminals.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150.

924.2.09 Service Entrance Caps (Weatherheads)

A.Requirements

1.Devices shall be listed to UL 514B, Conduit, Tubing, and Cable Fittings

2.The device shall be mechanically and environmentally compatible with the conduit that it is attached to.

3.Shall be as specified in the Contract or as approved by the engineer.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150 1797

SECTION 924 — Miscellaneous Electrical Materials

924.2.10 Transformers

A.Requirements

1.Transformers located within control cabinets shall be single phase dry type.

2.They shall be rated for 1.5 times the maximum load of the application.

3.All control transformers shall be listed to UL 5085-1 and certified to NEMA ST-20.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150.

924.2.11 Enclosures

A.Requirements

1.Enclosures shall be listed by an NRTL to UL 50

2.Shall comply with NEC Article 110.28

3.Shall be rated NEMA 4X

4.Shall be fabricated from Stainless Steel Type 316

5.Shall be free standing and capable of being pad mounted.

6.Shall have continuous door hinges with lockable door handles

7.Unless otherwise specified material to be type 316 SS with a brushed finish, depending on application,

with all hardware of the same or higher grade

8.Shall be sized to accommodate all of the equipment to mounted within it plus a minimum of 25 percent

to accommodate future requirements.

9.General construction shall be of sheet steel with all welds to be continuously finished smooth, free of all burrs,

scale and imperfections

10.Shall be stiffened to prevent any deformation or bowing during installation and after components are mounted

11.All doors are to be formed flush fitting with all welds ground smooth, latching as specified with permanent

gasket installed

12.Supply print pocket for documentation

13.Shall be provided with an Internal mounting panel

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 15

924.2.12 Service Disconnect Switch

A.Requirements

1.Use disconnect switches that are NRTL listed to UL 98 or 489 as appropriate with the voltage and ampere

rating specified in the Contract.

2.Use switches that are 2-pole, 3-wire, solid neutral with heavy duty rating, unless otherwise

specified. Switch may be installed separately or with a magnetic contactor. 1798

SECTION 924 — Miscellaneous Electrical Materials

3.Enclose the switch in a lockable, stainless steel, weatherproof enclosure that is rated 4X per NEMA 250. The

switch shall have an external lockable handle and shall provide for locking in either the “On” or “Off” positions.

Padlocks shall be included and shall be certified to ASTM F883-13 Grade 6 and comply with relevant safety

and security standards.

4.Use the proper sized lug for the cable used. Do not cut cable strands to attach to disconnect switches.

B.Fabrication

General Provisions 101 through 150.

C.Acceptance

General Provisions 101 through 150.

D.Materials Warranty

General Provisions 101 through 150.. 1799

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Source: Standard Specifications for Construction of Transportation Systems, 2021 Edition. Pages 1800–1809 of 2,050. View official source ↗

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