How to select Street Light Poles ?

How to select Poles ? 

Poles should initially be selected, according to lighting application needs and second, but equally important, according to the structural requirements imposed on the pole by the required lighting fixtures and bracketry. Before attempting to make this selection, it would be helpful to have an understanding of the terminology, such as steady wind velocity, gust velocity, EPA, special wind region and maximum weight. Then a step-by-step procedure can be followed to select the proper pole for your particular requirements.

Steady Wind Velocity

This is the maximum steady wind velocity expressed in MPH likely to occur in a specific location. Refer to Iso-Tach wind map on the next page for the wind velocity in your location.

Gust Velocity

Gust velocity is a momentary increase in wind causing a whipping action. In all cases, Hubbell pole calculations include a 1.3 gust factor over steady wind velocity. This means that poles designed to withstand winds of 80 MPH will withstand gusts to 104 MPH.

Effective Projected Area

Effective Projected Area (EPA) is the exposed surface area of a fixture or bracket multiplied by a shape factor which varies depending on the shape of the fixture or bracket. For example, a large rectangular fixture will present more resistance to the wind than will a round or cylindrical shape.

Special Wind Regions

Some locations such as mountainous areas and areassurrounding the Great Lakes exhibit wind velocitiesconsiderably higher than the surrounding areas. Consult local authorities to determine maximum wind velocities and select equipment accordingly.

Maximum Weight

This is the maximum allowable total weight the pole is capable of supporting. Its value is determined by the total weight of the lighting fixtures and bracketry for your application requirements.

Pole Selection Procedure

With an understanding of the parameters for poleselection, you can follow this simple step-by-stepprocedure and, with confidence, select a pole to meet your particular requirements.

1. Determine the site location and steady wind velocity by referring to the Iso-Tach map. If the location falls between Iso-Tach bars or on the 70 or 90 MPH bar, use the next highest wind velocity; i.e., 80 or 100 MPH. If the steady wind exceeds 100 MPH, consult factory.

2. Total the EPA for the required luminaires andbracketry.

3. Total the weight of the luminaires and bracketry.

4. Compare steps 2 and 3 with the maximum allowable EPA and weight as shown for the style, material and height pole required. The maximum allowable must be equal to or exceed the totals from steps 2 and 3.

Pole Selection Concerns

Reference the Pole Selection Guide and Installation & Maintenance Concerns on every pole catalog page.

Caution: These selection methods are guidelines only. Hubbell Lighting assumes no responsibility forselection and recommends you consult qualifiedprofessionals for verification of overall system design, site suitability, foundation considerations and applicable code and regulatory conformances.

Maintenance: The facility owner’s/manager’s regular scheduled maintenance program must include initial and regular follow-up inspections for structural damage, broken welds, tampering, nut loosening, missing wire covers, dangling electrical wiring, internal or external corrosion, foundation settlement, excessive shaft deflection and vibration for all lighting poles. Immediate repair or replacement may be necessary.

Overloading: Do not overload poles by attaching flags, banners or any items that can add excessive wind or mechanical load to designed pole assemblies.

Observation: Installation and local area conditions can dramatically affect lighting pole performance. Excessive vibration may result from some wind and mounting conditions. Only individuals with local knowledge, who have observed or inspected the site can effectively evaluate site specific issues. Consult the factory for information on vibration dampers, special corrosion, foundation settlement, excessive shaft deflection and vibration for all lighting poles. Immediate repair or replacement may be necessary.