Owner`s manual

10. Basic Tower Requirements

Customer supplied towers for the BWC EXCEL 1 Wind Turbine should meet the following mini-

mum requirements:

Tower Height: 9 m (30 ft) minimum, though we recommend 18 m (60 ft) or higher

Design Wind Speed: 54 m/s (120 mph)

Turbine Weight: 34 kgs (75 lbs)

Maximum Turbine Thrust Load: 890 N (200 lbs) @ 54 m/s (120 mph)

Blade Clearance: Top 1.1 m (44 in) of the tower must not exceed 12.7 cm (5 in) radius from the tower

center line

Dynamics: Not considered due to variable rotor speed

Stiffness: Tower top should not deflect more than 15 cm (6 in) @ 54 m/s (120 mph)

Turbine Mounting: Cylindrical, 108 mm (4.25 in) Outside Dia. See attached drawing

Tower Climbing: On non-tilting towers, provisions must be made to allow the tower to be climbed for

inspections and possible maintenance. Climbing pegs should be removable if they do not meet the blade

clearance requirement. On lattice-type towers, we recommend the use of horizontal laterals to facilitate

climbing. We recommend the use of anti-fall devices for towers requiring climbing.

Materials: We recommend low-carbon steel towers, with careful attention given to weld quality. Stress

risers and brittle materials must be avoided because of the possibility of fatigue and cracking. We do not

recommend aluminum be used due to the risk of cracking. Fasteners should be SAE Grade 5 or equiva-

lent.

Finish: We recommend hot-dip galvanizing after fabrication

Pipe / Tubing Sizes: The following standard steel tubing sections have ID and OD dimensions that are

compatible with the BWC EXCEL 1:

4.5 in. OD, 0.095 in. wall thickness

4 in. pipe, 0.120 in. wall thickness

120 mm OD, 5.0 mm wall thickness

120 mm OD, 2.5 mm wall thickness