Light poles or lampposts are designed to support single or multiple luminaires. This guide covers the installation of light poles.
Anchor bolts are the most commonly used method to secure poles to concrete foundations. Anchor bolts are specifically manufactured for pole foundations, and each pole requires anchor bolts of an exact diameter and length. New or existing anchor bolts should not be used without consulting the manufacturer's catalog or performing a thorough engineering analysis.
Before pouring a concrete foundation, it is important to ensure that the anchor bolt circle template conforms to the bolt circle of the pole base. The same is true for "precast" foundations. Also, radial orientation of the anchor bolts relative to the hand hole and mounting orientation of the luminaires is critical.
Anchor bolt projection (BP)
The height of the anchor bolt protrudes above the concrete surface.
The anchor bolt projection should be checked thoroughly. Too little projection may result in the pole not being properly secured; too much project may make the bolts subject to unwanted bending stresses. In addition, the base cover may not fit properly. Consult the manufacturer's catalog for the correct anchor bolt projection.
The concrete foundation's purpose is to support the pole under wind loads. It will have a number of steel reinforcing bars sized to prevent cracking and/or failure of the concrete. The dimensions of the foundation should be large enough for the soil to resist the OTM and other loads. Small, undersized foundations may cause the foundation to rotate or lean. The foundation will also have electrical conduit(s) to provide power to the luminaire. If more than one conduit is used, it is important to keep the conduits clustered in the center of the bolt circle with minimum protrusion above the surface of the foundation.
Concrete foundations must be designed by a qualified engineer with knowledge of local soil conditions. Some manufacturers, like Eaton's Lighting Division, can provide the loading conditions (OTM, weights, torsion and shear leads) to the foundation engineers. However, Eaton does not provide foundation design services.
Foundation location considerations
To protect the pole, foundations should have adequate setbacks from curbs to prevent bumper damage. Within parking lots, large elevated foundations may be used. Snow plowing should also be considered. When poles are laid out in a grid pattern or in a straight line, it is recommended that they be accurately set, which will result in an aesthetically pleasing appearance.
Assembly of the pole, brackets, luminaires and wiring is completed on the ground before erection. It is not advisable to erect poles without luminaires.
Leveling and plumbing poles
When erecting the pole, it should be "plumb," or perfectly vertical. This can be accomplished easily withe leveling nuts and washers. An accurate level is recommended for this operation.
Tightening anchor bolt nuts
Anchor bolt nuts must be tightened to torque values provided in the manufacturer's pole instruction sheets. A torque wrench is required for this operation.
A qualified electrician is required to perform the electrical installation in compliance with the National Electrical Code (NEC) and any other local codes that are required. Proper grounding is a must; an anchor bolt may not be used as a ground. Wire-ways and entrances should be protected so as not to chaff or abrade the conductors. There should be no strain on conductor connections.
Grout is not recommended for steel poles or poles using a base cover.
The space below the pole base allows for ventilation and keeps moisture from collecting inside the pole. This helps prevent corrosion. Also, visual inspections can easily be completed by lifting the base cover. Although rare, rodent issues can be addressed by inserting a wire screen in this space.
If a non-shrink grout is used, air channels must be provided to allow for adequate ventilation and moisture drainage to the interior of the pole.