625 Highway Lighting

General (625.01)

The following information does not alter or supersede the Contract Documents.  It is provided as a guide for ODOT personnel assigned to a project to help them with their work.

Electrical construction work must adhere to the Contract Documents which commonly include proposal notes, project plans, Standard Drawings, and Construction and Material Specifications.  In addition, there may be building or electrical codes or change orders that must be followed.

Contractor Prequalification

Only Contractors prequalified by the ODOT Office of Contracts for Work Type 43 ‑ Highway Lighting shall be allowed to do the highway lighting items of work on the project.

Respect for Contractor

Contractors are prequalified for specialized work types.  They bring expertise to the project and an independent perspective from the project management team.  As the Contractor reviews plans and specifications, he wants to ensure that he can install material that will ultimately operate as the designer intended.  The Contractor relies on the Engineer to guide the project, to approve materials and work, and to ensure that he will be paid for work completed.  It is important to remember that even when the roles of the project team and the Contractor conflict, successful completion of the project relies on all those involved and the maintenance of good working relationships.

Protection of Utility Lines

The Contractor is to notify all utilities before construction work begins.  Names and addresses of these utilities are given in the project plans.  It is the Contractor’s responsibility to contact the Ohio Utility Protection Services (1‑800‑362‑2764) to have utility locations marked in all areas where digging is involved.

Plan Discrepancy, Design Ambiguity, Consultation with Designer

When there is a question regarding the intent of the plan, the Engineer should:

1.      Define the discrepancy or ambiguity.

2.      Determine if more than the highway lighting is affected.

3.      Identify the standard drawings and specification pertinent to the situation.

4.      Determine potential solutions.

5.      If the issue involves the location of the luminaires or light poles, the mounting height of the luminaries above the pavement, the luminaire to be used or the lamp to be used, the Engineer should consult ODOT’s design office and the Designer to ensure that the performance goals for the lighting system will still be met by the solution under consideration.

6.      Consider the maintenance of the installation if the solution is implemented.  Will parts not normally stocked by the maintaining agency be required, or will tools and equipment not normally at the disposal of the maintenance crews be required, or will special training of the workers be required?

7.      Evaluate potential solutions for safety.  Consider measures needed to keep errant vehicles from striking the item, the danger to those who must maintain the installation, and the danger to traffic from the maintenance activities.

8.      Determine if applicable codes and regulations will be met.  Commonly involved will be the National Electric Code, The National Electric Safety Code, and Utility Company requirements.  There may also be state and local building codes.


Materials (625.05)

Highway lighting items are found in 625 with detailed descriptions of materials in 725.

In general, all material furnished shall be new and of first quality, unless otherwise noted in the plans, and shall be identified either by a permanently attached name plate or by an indelible marking.

Before installation, all material shall be checked to determine that it is indeed the material that has been specified, the appropriate material process has been completed, and all paperwork is in hand. 

Four procedures are commonly used to ensure that the correct materials are installed.

1.      Qualified Products List (QPL).

2.      ODOT Plant Sampling and Testing Plan (TE‑24 Certification).

3.      Certified Drawings or Certified Catalog Cuts.

4.      Project Inspection of Material.

Qualified Products List

Lighting material which may be on a Qualified Products List:

1.      Pull box.

2.      Junction box.

3.      Conduit.

4.      Wire and cable.

5.      Ground rod.

6.      Photocell.

The Office of Materials Management maintains the Qualified Products Lists.  The Engineer can verify that the material is on a Qualified Products List (QPL) through ODOT’s SiteManager.  After verifying that the material being supplied is that specified by the Contract and on such a list, the project may accept the material. 

TE‑24 Material Certification

Lighting material for which TE‑24 Certification may be obtained:

1.      Pull box.         

2.      Junction box.

3.      Anchor bolt.

The ODOT Plant Sampling and Testing Plan (TE‑24 system) is administered by the Office of Materials Management.  This system was designed to allow certain material to be sampled, tested, approved, and stocked for future use on ODOT projects.  The material is inspected at the manufacturing or distribution site.  Each approved lot of material is assigned a certification number and documented on Form TE-24.  Material from the approved lot may then be transferred directly to an ODOT project or it can be transferred to other warehouses, such as a Contractor’s storage facility, and then transferred to a project at a later date.


Working Drawings (625.06)

Lighting material requiring Certified Drawings or Catalog Cuts:

1.      Luminaires.

2.      Luminaire supports (towers, lowering devices, poles, bracket arms).

3.      Power service equipment.

4.      Portable power units.

5.      Temporary lighting systems.

The Contractor shall submit two copies of shop drawings or catalog cuts prior to the installation of the material.  The submittal ensures that the state has a good record of the material installed should there be any question about the material meeting criteria or should additional or replacement units be required.

Each submittal shall identify the project and the bid reference number under which the item is being provided.  Drawings or catalog cuts shall be clearly marked by circling or underlining to indicate the exact item and options being supplied.  If a given item is to be supplied under multiple bid item reference numbers, separate and complete documentation packages shall be submitted for each bid item reference number.  If multiple items are to be supplied under a single bid reference number, all the items to be supplied under said reference number shall be submitted as a package.  The Contractor’s cover letter for each package is to certify in writing that each manufactured item in the package conforms to all contract requirements for that item.

The submittal of certified drawings or catalog cuts does not relieve the Contractor from furnishing additional information concerning the material deemed necessary by the state.

Project Inspection of Material

The following materials are normally manufactured to standards that meet ODOT criteria and therefore do not have a QPL, do not normally have a TE-24, and shop drawings or catalog cuts are normally not required:

1.      Exothermic welds.

2.      Insulating varnish.

3.      Split bolt connector.

4.      Expansion fittings.

5.      Connector kits.

6.      Splice kits.

7.      Copper crimps and compression connectors.

8.      Light pole decals.

9.      Circuit identification tags.

10.  Cable grips.

11.  Wood service poles.

12.  Fuses for control center and connector kits.

13.  Photoelectric cell and bracket.

14.  Secondary lightning arrestor.

15.  Guy anchors and anchor rods.

16.  Weather heads.

17.  Watertight hubs.

18.  Remote ballast enclosures and mounting brackets.

Project inspection of material is used to verify that the material at hand is listed on a QPL or described on a TE-24 for which certified shop drawings or catalog cuts have been received and that the material complies with the requirements of the Contract Documents.  For material not on a QPL, which does not have a TE-24, and for which shop drawings or catalog cuts are not required, the project inspection of material is limited to comparing the material at hand with the requirements of the Contract Documents.


Luminaires (625.08)

A luminaire consists of a housing which contains a reflector, refractor, lamp socket, and lamp. Unless otherwise specified, the housing will also contain the ballast components (core and coil, capacitor, starter) required for the lamp being used. The housing may have optional components, such as fuses or a photocell when specified. The housing is fitted with the necessary clamps or other provisions for attaching the luminaire to its support and terminal block for the incoming power.

Verify that the luminaire installed at each location is one of the luminaires listed in the plan for that location.  Verify that the distribution, lamp type, and lamp wattage are as specified in the plans.  Instructions packed with the luminaire will explain the distributions that the luminaire is capable of producing and how to set any adjustments in the luminaire to provide each distribution.  Verify that ballast is compatible with the circuit voltage and lamp.

Conventional Luminaire

The conventional luminaire used by ODOT is also known in the trade as an “Ovate” or “Cobra Head” fixture.  It may be equipped with a flat or a dropped style refractor as specified.

Verify that the luminaire is properly leveled according to the instructions packed with the luminaire.

Side‑Mount Roadway Luminaire

This luminaire reminds one of a floodlight.

Verify that the “tilt” has been set as specified in the plan according to instructions packed with the luminaire.  Verify that the luminaire is oriented “normal” to the line of survey for the roadway being lighted unless the plans stipulate otherwise.

High Mast Luminaire

These luminaires are mounted on tall structures equipped with devices to bring the luminaires to ground level for servicing. 

Verify that the luminaire is not “twisted” with regard to its bracket arm.  There are three distributions commonly used.  If the luminaire has a rotatable refractor, verify that it has been aligned properly.

Low Mast Luminaire

Low mast luminaires are the same luminaire as a high mast luminaire, but installed as a fixed unit on a pole of more traditional height.

Verify that the luminaire is not “twisted” with regard to its bracket arm.  There are three distributions commonly used.  If the luminaire has a rotatable refractor, verify that it has been aligned properly.

Underpass Luminaire

Underpass luminaires are used to light roadways beneath bridge decks.  Commonly they are wall mounted on a pier cap or abutment.  Sometimes they may be ceiling mounted on the underside of the deck or to a panel attached to the deck supporting beams or pendant mounted on suspension pipes attached to the structure.  Occasionally they will be post top mounted on short poles.

Verify that the luminaire has been attached to the structure at the location and in the manner specified.


Verify that the lamp is one of the brands listed in the plan. Verify that the lamp type and wattage is compatible with the luminaire and its ballast.  Unless otherwise specified, for a particular installation, the lamps are to have clear envelopes.  Do not substitute lamps with “frosted” envelopes.  Verify that the installation date has been properly marked on the base of the lamp.  Instructions packaged with the lamp explain how to use the dating provision built into the base.


Luminaire Supports (625.09)

The inspection of the supports (poles, arms, towers, lowering devices, brackets, etc.) consists of two phases: (1) inspection of the components and (2) inspection of the completed assembly.  While these may be done together, it is better if the components are inspected upon arrival at the project since there is more time to obtain replacements or correct faults.

Inspection of Support Components

Three areas are examined in this phase: welding, galvanizing, and compliance with shop drawings.

Inspection of Welds

Examine each weld for the following:

1.      Each of the welds called for by the certified shop drawings is present and there is no weld present that is not shown on said drawings.

2.      There is no misalignment of the parent material being joined by the weld.

3.      There has been no warping of the parent material by the weld.

4.      Each weld is of the type, size, and continuity shown on the shop drawings.

5.      Each weld is of full cross-section without excessive concavity or convexity.

6.      There is no over filling or cratering at either the beginning or end of the weld.

7.      There is no undercutting (a shallow groove melted into the base metal adjacent to a weld and left unfilled by weld metal) along any weld.

8.      There is no porosity (pitting or pinholes) in any weld.

9.      There is no crack or discontinuity in either the base metal or weld material along any weld.

Inspection of Galvanizing

Examine the galvanizing for the following:

1.      There are to be no spots where the galvanizing is missing or loose and can be flaked off with a penknife.

2.      There should be no ash that has been picked up from the top of the bath which usually appears as coarse lumps.

3.      There should be no pimples from entrapped bath scum particles.

4.      There should be no blisters from hydrogen gas absorbed during pickling being released and rupturing the surface of the galvanizing.

5.      There should be no flux inclusions from flux picked up from the top of the bath during dipping and burned on during immersion.

6.      There should be no lumps or runs of excess zinc from delayed run‑off of molten metal trapped near surface discontinuities, such as joints, seams, or holes as the part was lifted from the bath.

7.      There should be no rust stains from impurities from the pickling process weeping at seams and folds.

8.      There should be no general overall roughness from over pickling or of excess zinc bath temperature and/or immersion time.

9.      There should be no patches of dull, gray coating from slow cooling of heavier cross-sections of the part after immersion.

10.  The galvanizing should have a uniform appearance.

Excessive galvanizing faults, gross imperfections, or overall poor workmanship may be cause for rejection of the support.  Minor scratches in galvanized surfaces can be accepted.

Compliance with Shop Drawings

Supports are frequently shipped to the job site and stored prior to assembly and erection as components which give opportunity for the components to get mixed up leading to improper assemblies since the basic design often does not prevent errors.  Therefore, prior to beginning the assembly of a given support, it is necessary to check the major dimensions of the various components against the shop drawing for the support to verify that this has not occurred.

On poles, verify the length, base diameter, top diameter, and wall thickness of each pole, or section of the pole, for poles shipped in multiple sections that are field assembled.  Verify the length, width, and thickness of the base plate along with the bolt circle diameter, bolt hole size, and number of anchor bolt holes provided.

On bracket arms for conventional supports, verify the arm length and arm rise.

On lowering devices, verify the diameter of the luminaire mounting ring and number of luminaire arms on the ring.  Also, verify the length of the power cord along with the wire size and number of conductors in the cord. Verify the diameter and length of each piece of hoisting cable.

Assembly of Supports

Support components stored in the field should be kept off the ground to prevent finish blemishes where the component lay in contact with a damp surface earth or water.  Support components and assembled supports should be loaded, transported, unloaded, stored, and erected in a manner avoiding damage to the factory applied surface finishes.

On multi-piece poles, verify that the sections to be assembled are the correct pieces for the pole at hand.  Before tightening each telescopic joint between the sections, verify that the sections are properly oriented and that the male section has been marked to indicate when full insertion has been achieved.  Verify that the process used for tightening the joint between sections is approved by the pole manufacturer and that the pole is not bent during the tightening process.

On each steel light pole used with an aluminum transformer base, verify that both the bottom of the pole base plate and the top of the transformer base were given a coat of zinc rich paint prior to assembly.

On each light pole, verify that the cable grip in the light pole is properly installed as shown in SCD HL‑10.12 to prevent damage to the pole and bracket cable.

On each light tower, verify that the luminaire ring has the correct number of mounting arms and that each arm is attached such that when the tower is erected, the arms will be in the positions relative to the roadway as shown on SCD HL-10.31.  If the lowering device is equipped with top laches, verify that when the luminaire mounting ring is fully raised and latched, the latch indicator on each latch will be in the “extended” or “visible” position.  Verify that all moving parts on the head frame assembly and hoist mechanism have been lubricated in accordance with the manufacturer’s instructions.

Verify that all parts are in place and all fasteners have been properly installed according to the manufacturer’s instructions.

Verify that each hand hole door or cover closes with no excessive gaps.

Verify that a light amount of anti‑seize or grease lubricant has been worked into the threads of each fastener which hold each removable cover in place.

Erection of Supports

Prior to erection, verify that nuts can be easily turned by hand onto the threads of each anchor bolt.

When leveling nuts are to be used, verify that the leveling nuts are level before beginning the lift to set the support.

Each support should be lifted and set by crane with the hoist line attached at a point as far above the support’s center of gravity  as possible, with a tethering cable from the lifting point to the base of the pole.  The lifting point on poles made up of sections slip fitted together should be above the uppermost joint.  Hoisting should be smooth and continuous without abrupt jerks.  Light tension should be maintained in the hoist lines until an anchor nut has been threaded onto each anchor bolt far enough that the bolt is projecting though the nut by a full thread.

Verify that each support with a transformer base has been plumbed using leveling shims approved by the base manufacturer, installed between the base and the foundation according to the base manufacturer’s instructions and limitations and that the anchor nut on each anchor bolt has been properly tightened.

Verify that each support with an anchor base installed directly on a foundation, without leveling nuts, has been plumbed using leveling shims approved by the pole manufacturer. Each support is installed between the base and the foundation, according to the pole manufacturer’s instructions and limitations, and the anchor nut on each anchor bolt has been properly tightened.

Verify that each support with leveling nuts is plumbed by adjusting the leveling nuts. Verify that both the anchor nut and the leveling nut on each anchor bolt are properly tightened.

Verify that a light tower has been plumbed early in the morning when the heat effect from the sun is at a minimum.

Verify that each support has been plumbed when there is no appreciable wind.

Verify that the space between the top of the foundation and the base of the support has not been grouted.

When a high mast support (light tower) is equipped with a lowering device that has top latches, verify that the ring engages all latches simultaneously. This is often referred to as “leveling” the ring.  It should be done following the manufacturer’s directions.  Generally the procedure is to place a block on each hoisting cable which is attached to the ring a few inches above the ring in such a manner that the block will slide along the cable when the block contacts the portion of the mechanism at the top of the tower. The ring is then raised until all blocks have made contact, but not fully raised.   The ring is lowered and the distance between each block and ring is measured. Hoisting cables are adjusted to make the measurements equal. The process is repeated until no further adjustments are required.  The blocks are removed and the lowering device operated several times through its full cycle watching all latches for proper operation.

Verify that support identification decals have the proper legend and the decals are located approximately 7 feet (2.1 m) above the base of the pole facing oncoming traffic.


Foundations (625.10)

Foundation inspection normally consists of three parts: location, excavation and concrete placement.

Foundation Location

After the location of each foundation is staked, verify that the location is specified in the plan and that Ohio Utility Protection Service and all utilities in the area have been allowed at least 48 hours to mark their utility locations relative to the proposed foundation.  Verify that the location appears logical.  Be alert for the following:

1.      Installing the lighting item at the staked location will require removal of vegetation that shields adjacent property owners from the highway.

2.      Installing the lighting item at the staked location will locate the item at the top of the back slope, in a cut cross-section, or at the bottom of the fill in a filled cross-section where guardrail is to be used to keep errant vehicles from going down the slope.

3.      Installing the lighting item at the staked location will place the item under an overhead utility line or over an underground utility line.

4.      Installing the lighting item at the staked location will require a graded access drive for the construction that has not been addressed in the plan.

The designer should be consulted prior to relocating any support more than 10 feet (3.0 m) or if two or more adjacent supports need to be relocated.


Foundations are to be placed only in undisturbed soil or compacted embankment.

If a minor cave‑in should occur, the Contractor may, with the approval of the Engineer, continue to excavate using sleeving or casing.  When bedrock is encountered, the Engineer may reduce the specified foundation depth.

If construction crews must leave the job site with a hole unfilled, it shall be covered and marked with cones, barrels, or warning tape.

Placement of Concrete

Verify that the top of the foundation will be at the proper elevation.

Tops of foundations shall be finished smooth and level to enable proper plumbing of the light pole.

Verify that the anchor bolts are of the correct size and number and that each bolt is securely held in the correct position.  The use of an anchor bolt setting template is encouraged.  Verify that each anchor bolt will project the proper distance from the foundation.

Verify that conduit ells are present and that each ell is of the correct size and material and properly oriented.

Verify that all reinforcing bars are present and that each is of the correct size and shape.

Verify that all items to be cast into the foundation, along with any forming aids, are secured in such a manner that they will not move out of position during the placement of concrete.

Verify that water encountered in the foundation excavation is pumped out before concrete placement.  If this is not feasible, verify that the concrete is placed by the tremi‑tube method.

Verify that the concrete is of the proper design, has been properly mixed, has the correct slump, and is properly handled during placement.  Verify that the concrete is vibrated to eliminate voids.

Verify that the top of the foundation is properly finished and that the concrete is properly cured.


Junction Boxes (Handholes) & Pull Boxes (Manholes) (625.11)

Junction Boxes (Handholes)

Verify that each junction box is of the correct size and material and securely fastened in the correct location.  Verify that a light amount of anti‑seize or grease lubricant has been worked into the threads of each fastener holding the cover in place.

Pull Boxes (Manholes)

Verify that each pull box is of the size and material specified.

Verify that each pull box is at the planned location unless the planned location puts the box in a low spot with respect to the surrounding surface.  In such cases, notify the Engineer so that the Engineer, in consultation with the designer, may attempt to move the box to a location where it will be less likely to hold water. 

Verify that a light amount of anti‑seize or grease lubricant has been worked into the threads of each fastener holding the cover in place.


Raceways and Conduits (625.12)

Verify that each conduit run is of the correct size and material.

Verify that each cut end on each piece of conduit is reamed to remove rough edges.

Verify that all field cut threads on galvanized conduit have been coated with zinc rich paint.

Verify that each expansion or deflection fitting has a bonding strap for ground continuity when used with metal conduit.

Verify that each conduit run has been properly fastened in place.

Verify that the Contractor shall check each run of conduit by rodding (pushing a mandrel through the empty conduit) or pulling a cleaning puck through the conduit.

Verify that each run of conduit being left empty for future use contains a No. 10 AWG pull wire or equivalent.

Verify that each end of each conduit run is terminated either in a box connector that contains an integral bushing or with a separate bushing to protect cable pulled into the conduit.


Trenching (625.13)

Verify that the trench did not deviate more than 6 inches (150 mm) from the designated line, unless such deviation has been approved by the Engineer.  Verify that the sidewalls and bottom of the trench do not have any protruding sharp rocks.

When duct-cable is installed in the trench, verify that the backfill material within 2 inches (50 mm) of the duct-cable does not contain pieces larger than 1/2 inch (13 mm).

Verify that the backfill is placed in compacted layers exceeding no more than 4 inches (100 mm) in thickness.

When caution tape is specified, verify that the tape is installed 6 inches to 8 inches (150 to 200 mm) below grade.


Power Service (625.15)

Power service includes all equipment from the connection point to the utility company to the beginning point of the individual lighting circuits.

Verify that the power service location will be readily accessible to both maintenance personnel and utility company personnel.  There should be a safe parking area for service vehicles since the site will be visited regularly.  The location should not be prone to standing or flowing water during rain events or to drifting snow.  If the location appears unreasonable, involve the designer and utility company as soon as possible, since moving a power service often means redesigning the lighting circuits.

Verify that the Contractor has been in touch with the utility company and is aware of any utility company requirements which may differ from the requirements of the Contract Documents.

Verify that the photocell is facing the north sky, unless otherwise stipulated by the plan, and that no artificial lighting source is disrupting its proper operation.

Verify that the conduits are neatly routed and fastened securely in place.

Verify that enclosures are securely mounted.

Verify that enclosure covers are in place and fasteners for the covers have had anti-seize or grease worked into the threads.

Verify that moving parts of the switch gear have been lubricated and operate smoothly.

Verify that no debris has been left in enclosures and that the wiring in each enclosure is neat, orderly, and tied into place where appropriate.


Grounding (625.16)

The conducting portions of those items which contain electrical conductors are to be connected to each other and to earth electrodes to lessen the chance of injury and damage from unwanted electrical currents.  Connecting the various conducting portions together to form a continuous path for the flow of stray electrical currents, often referred to as bonding in ODOT’s projects, is generally incidental to the construction.  Installation of the earth electrodes and the connection of the conducting portions to those electrodes is often referred to as grounding, and in ODOT’s project’s payment is somewhat related to the electrodes installed.

Ground Rods

Verify that the specified ground rods have been installed.  When additional rods have been added to lower the resistance, verify that the installation of each rod was approved prior to its installation. 

Verify that the connection between the ground rod and the grounding cable is an exothermic weld.  When additional rods have been added to reduce the resistance, verify that the additional connections are exothermic welds.

The normal ground rod item is for one rod, driven into earth, and the lead between the rod and the first connection and associated connections.  The earth resistance is then checked.  When said resistance exceeds the specified limit, an additional rod is to be driven and connected to the first. The earth resistance of the pair is then checked. The process is repeated until the resistance of the group is lower than the specified limit.  Payment is then made for each rod installed at the “per rod price.” 

ODOT has reserved the right to approve the use of each additional rod before it is installed and may decline to install additional rods, thereby stopping the process at any point.  When ODOT stops the installation of additional rods, it may decide to take another course of action to lower the earth resistance.  If no additional action is taken, then by default, the earth resistance becomes acceptable as it stands.

Exothermic Welds

An exothermic weld often has a rougher surface texture on the weld metal than one may be used to seeing, but the weld is not to have other signs of a poor quality weld, such as porosity, cratering, cracking, or undercutting.

Structure Grounding

Verify that each grounding electrode is acceptable before structure construction makes modification of the electrode, or the installation of additional electrodes, impractical.  Remember, if some of the electrodes are driven rods that such rods are incidental to the structure grounding system, not separate items.  However, if due to high resistance, additional rods are driven, those rods are not incidental to the structure grounding system.

Verify that the necessary bonding jumpers are in place and functioning correctly before structure construction makes the installation of additional jumpers impractical.

Structures present special needs.  Not only is it impractical to have a separate ground rod for each light pole or similar item mounted upon the structure, but there are also elements of the structure itself that need grounding.  The normal practice is to use bonding jumpers to connect all exposed metal items together and therefore to the several electrodes which frequently utilize the main conducting portions of the structure as the main grounding buss.  This means that electrodes are often under footers and bonding jumpers are frequently embedded in the structure.  If something is left out or does not function as intended, and it is not discovered until the final stages of construction, the grounding can become expensive, unsightly, and less than desired.  Unfortunately, structure designers all too often include little in the way of specific details for the structure grounding.  Therefore, it is imperative to constantly think ahead to fully understand where each electrode and jumper is to be located and to verify that it is in place and functions correctly at each stage.

Bonding along Circuits

Verify that all of the conducting items which contain the conductors of each circuit are bonded to form a continuous path back to the source of the circuit.

At light poles, verify that metal conduits entering the base of the pole are bonded to the pole.

At pull boxes, verify that the metal conduits entering the pull box are bonded together and the metal lid and lid frame are bonded to the metal conduits.

At junction boxes, verify that the metal conduits entering the junction box are bonded to the box.

At the expansion and deflection joints in conduits of conducting materials, verify that a bonding strap has been install across the joint.

When non-conducting conduit or duct is used, verify that a grounding conductor has been installed to provide for the continuous grounding path.


Wiring and Cabling (625.17)

Field wiring of highway lighting circuits is broken into three types.

Pole and Bracket Cable

Pole and bracket cable is the insulated, single conductor used in a light pole (but not in a light tower) to connect from the distribution cable, up the pole, and out the bracket arm to the light fixture. In a tower, the electrical wiring from the base of the tower to the luminaires is a component of the lowering device.

Verify that each run of cable is of the size and type specified. The wire size and insulation are to be indelibly marked on the insulating jacket at frequent intervals along the length of the cable.

Verify that each run of cable is installed in a continuous piece without inline splices between the terminations shown on the plan.

Verify that the insulating jacket wasn’t nicked, nor portions shaved away, as the cable was pulled into place.

Verify that the cable was not stretched as it was pulled into place.  If the cable can be pulled back and forth by hand enough to move both ends, stretching probably did not occur.

Verify that a cable support was installed at the upper end of the vertical run of cable up the pole.

Verify that there is enough length on each end of the run for the cable to be routed properly to its termination and still remain slack.

Distribution Cable

Distribution cable is the insulated, single conductor used to construct lighting circuits from the control equipment of the power service to the disconnect kits of a light pole, the terminal block of a light tower, or the disconnect switch for underpass or sign lighting.

Verify that each run of distribution cable is of the size and type specified. The wire size and insulation are to be indelibly marked on the insulating jacket at frequent intervals along the length of the cable.

Verify that each run of cable is installed in a continuous piece without inline splices between the terminations shown on the plan.

Verify that the insulating jacket wasn’t nicked, nor portions shaved away, as the cable was pulled into place.

Verify that the cable was not stretched as it was pulled into place.  If the cable can be pulled back and forth by hand enough to move both ends, stretching probably did not occur.  Unfortunately, for the larger wire sizes and the longer runs commonly encountered in highway lighting circuits, the cable cannot be pulled by hand.  The most common indication of stretching is when the length of pulling lead exiting the raceway is greater than the length of cable entering the raceway, or the pulling forces are greater than normally encountered, both of which are not easily detected by anyone other than experienced installers.

Verify that there is enough length on each end of the run for the cable to be routed properly to its termination and still remain slack.

All cables shall be labeled in accessible enclosures (pull boxes, hand holes, transformer base, device housing, etc.).  A minimum of 5 feet (1.5 m) of extra cable shall be provided for each conductor at all terminal points.


Duct-cable consists of insulated conductors, of the type used for distribution cable, installed into a duct and shipped as an assembly to the project. It is used in place of conduit and distribution cable to speed the installation of underground circuits.

Verify that the temperature of the duct‑cable was above 32 °F (0 °C) throughout the installation process.

It is permissible to install duct-cable when the outdoor air temperature is actually below those temperatures, but the Contractor must obtain authorization from the Engineer.  The Contractor shall submit, in writing, his method of heating the duct-cable and maintaining the duct-cable at a uniform temperature throughout the installation process.  To ensure that the duct-cable is heated uniformly, the heating process shall keep the temperature of the duct-cable above 32 °F (0 °C) for a minimum of 24 hours prior to installation.  Under conditions, such as the preceding, where the temperature of the duct-cable can be expected to vary widely during the installation process, the expansion and contraction of the duct-cable must be taken into consideration.  Typically, the duct-cable length will decrease or increase 1 foot per 1,000 feet (0.3 m per 300 m) for each 10 °F (5.6 °C) decrease or increase in temperature.

Verify that the duct of the installed duct-cable extends out of any conduit sleeve through which it passes enough to allow for the expansion and contraction in the duct due to seasonal changes in temperature.  Typically a projection of 2 to 3 inches (50 to 75 mm) is appropriate at the usual installation temperatures for the lengths of run typical in ODOTs installations.

As received on the reel from the manufacturer, it will appear that the cables inside the duct and the duct are equal in length, but in reality the cables are shorter than the duct.  In order to reel the assembly onto the shipping spool, both the cables and the duct were anchored to the spool. As the duct cable assembly is unrolled from the shipping spool, the cables will be drawn into the duct resulting in empty duct at the start of the run.  For the assemblies typically used in ODOTs projects, leaving 25 feet (7.6 m) of duct for each 1,000 feet (300 m) of run to be installed, in addition to that required as slack for connections at the start of the run, will compensate for this.  At the end of the run, only the slack amount for connections is required.

Verify that the insulating jacket of each cable within the duct has not been damaged when the duct was stripped to allow the connections to be made.  Often the length of duct to be stripped is such that no protection can be slid over the cables and into the end of the duct, which means that the cables within are saved from damage only by the skill of the person stripping the duct.

When a duct cable assembly has been passed through a conduit sleeve, verify that the duct has been sealed to each end of the sleeve by means of a molded boot or wrapped sealing pad.

Verify that the seal installed between the cables and the duct is installed in the same location and in the same manner as outlined under the installation of distribution cable into conduits.

Verify that there is enough length on each end of the run for each cable to be routed properly to its termination and still remain slack.

Conductor Identification

At each access point (pole base, pull box, junction box, switch gear enclosure, etc.) each conductor of each run of the field wiring (pole and bracket cable, distribution cable, duct-cable) of each circuit is to be identified by applying a tag to the conductor indelibly marked to indicate the circuit and the use of that conductor within the circuit.


Connections (625.18)

This covers the connection of the field installed wire and cable to other such wire and cable and to the various items of equipment.

Sizing Conductor to Device Terminal

When the circuit conductor is of a larger size than the device terminals can accommodate, verify that the connection has been made by splicing a short piece of smaller wire onto the end of the large wire and then connecting the smaller wire to the device terminal.  The smaller wire is normally identical to the larger wire in all aspects except for size.  The smaller wire must be large enough to carry the current that the circuit protection will allow.  It is not acceptable to cut back some of the strands of a conductor, so that the remaining stranded will fit into the terminal.

Crimped Compression Connections

Verify that the die in the compression tool was for the connector applied. The connector is sized to match the wire to which it was applied and the tool used was of a type that did not release the connector from the die once compression started until full compression was achieved.

Pull-Apart and Bolted Connections

Verify that the internal connector is properly applied to the conductors.

Verify that the insulating cover was cut to proper step for a snug fit over the insulation on each entry to the housing.

Verify that the internal parts are all present in good condition and are fully seated into the housing.

Verify that the male half of the housing is a snug fit and fully inserted into the female half of the housing.

Verify that a thin coating of the kit manufacturer’s approved, non-conducting grease has been used at the joint between the two halves of the housing, between the housing and each cable entering the housing, and on other internal parts, as show in the manufacturer’s instruction, which allow the parts to slide smoothly into place and help seal out water.

Verify that there are no sharp bends in each cable where the cable enters the housing sufficient to cause the housing to pull away from the insulating jacket on the cable.

When the kit is to contain a fuse, verify that the fuse is of the proper ampacity.

Where the kit contains bolted connections, verify that the connections have been properly tightened before the housing was closed.

Verify that there is sufficient slack in the cables being connected to permit bringing connector kits outside of the pole, transformer base or junction box in which it is housed for servicing.

Unfused Permanent Connections

Verify that the internal connection is via a proper crimp compression connector.

Verify that the mold surrounding the connection is completely filled with resin.

Verify that the connection is positioned within the mold such that the resin properly surrounds the connection.

Verify that there are no voids in the resin.

Verify that no fillers have been used.

Verify that the resin has properly set.


Testing of Installation (625.19)

There are a number of tests normally utilized to ascertain that the lighting installation has been well constructed and is in good operational order. For a particular test to have meaning it must be properly conducted and the results properly interpreted.

Verify that the equipment used to conduct the test is in working order and calibration.

Grounding Electrodes and Grounding Systems (625.19.B)

Verify that each specific grounding electrode meets the requirements of the earth resistance test. 

The first key to conducting a successful test of a grounding electrode is to understand what constitutes the electrode.  A single driven rod is an electrode.  When that rod fails the earth resistance test and another rod is added, the electrode then becomes both rods together.  However, in the case of a light tower where two rods are typically specified, the initial electrode is the two rods together rather than each rod separately.  In structure grounding, the cluster of driven piles at the end of a pier footer should be considered as a single electrode, with the cluster at the other end of that same footer considered as a separate electrode.  A continuous grid of mesh, bars, or cables laid beneath a footer is one electrode, but separate grids under different portions of the same footer are separate electrodes.  Wires buried in a radial pattern from a single pole constitute an electrode.

The second key to successful ground resistance is to understand the limitations of the various test instruments and procedures.  The chosen procedure must be appropriate for both the electrode under test and the conditions in which the electrode is installed and the instrument must be capable of producing valid results for the situation at hand.

Circuit Continuity (625.19.C)

The key to the proper checking of circuit continuity is to remember the objective and to test one conductor at a time.  The objective is to see that the conductor is connected to the desired device point and the conductor has not been connected to any other devices.  The difficulty is that the devices are scattered over a large area, thus, requiring the other conductors of the same circuit to be used as returns for the test signal.  For the test to be of use, the testing must start at one node in the circuit and test all connections along an isolated link from that node. Additional nodes and links are then added one at a time and the continuity of the conductors rechecked until the entire circuit has been verified.

Cable Insulation (625.19.D)

This test is designed to verify that the insulation of each conductor in the circuit, and permanent and bolted connections in that conductor, are in good conditions to impress a much higher than normal voltage on the conductor using the change in leakage current over time. Care must be used not to impress the test voltage on devices normally connected by the circuit since the devices would probably be damaged.  Since the other conductors in the circuit must often be used as the return path, it is necessary to use care to ensure that other conductors are not damaged while serving as signal returns and careful interpretation of the results to determine whether the leakage is from a conductor failing the test or from a failure in the return path.

Lowering Device Operation (625.19.E)

This test is simply repeated operation of the lowering device on a light tower to verify that is operates smoothly and correctly throughout its full range cycle of motions.

System Performance (625.19.F)

The test uses the concept, “infant mortality,” to determine if the equipment is likely to operate satisfactorily throughout the projected life of the installation.  The concept is that the equipment is most likely to fail from manufacturing defects and installation in the first few hours of use, and once these hours are past, it is likely to run the rest of its life with only normal maintenance.  In conducting the test, it is important to recognize the significance of each component malfunction encountered and to properly interpret whether the malfunction indicates a need to extend the test period. 


Information to Maintaining Agency

Ensure that each maintaining agency receives the documents pertinent to the maintenance and operation of the lighting units for which it is responsible.  Typically included are:

1.      A copy of the plan marked to show any changes made during the construction.

2.      A copy of each certified shop drawing or catalog cut.

3.      A copy of each instruction or parts manual supplied by each manufacturer.


Documentation Requirements

1.      Luminaires.

a.       Luminaire has the distribution, lamp, and aiming stipulated in the Contract Documents.

b.      Luminaire has been “leveled.”

2.      Supports.        

a.       Support is the one stipulated for that location by the Contract Documents.

b.      Support is comprised of the correct components according to the certified shop drawings.

3.      Pull boxes.

a.       Pull box is the size and type stipulated for that location by the Contract Documents.

b.      If supplied under plant sampling and testing program, it has a TE‑24.

c.       Drain is documented on form CA‑P‑1.

4.      Conduit.

a.       Conduit is the size stipulated for that location by the Contract Documents.

b.      Conduit is of the material stipulated for that location by the Contract Documents.

c.       Measure length installed.

5.      Trench.

a.       Location and depth is as stipulated by the Contract Documents.

b.      There are no sharp rocks in backfill adjacent to duct.

c.       Backfill is placed in 4 inch (100 mm) lifts and mechanically tamped.

d.      Measure length installed.

6.      Grounding electrodes.

a.       Electrode is installed as stipulated for that location by the Contract Documents.

b.      Grounding conductor connected to ground rod with exothermic weld.

c.       Document ground resistance.

7.      Wire and Cable.

a.       Wire size and insulation is as stipulated for that location by the Contract Documents.

b.      Measure length installed.