System Operation - Bergey 24 VDC B Owner's Manual

C. Nacelle
The nacelle is the fiberglass housing around the
main body of the machine. It contains the main
structural "backbone" of the turbine (called the
mainframe), the rectifier, the slip-ring assembly,
the yaw bearings, and the tower mount. The yaw
bearings allow the wind turbine to freely pivot
around the top of the tower so that the rotor will
face into the wind.
The slip-ring assembly is the electrical connection
between the moving (as it orients with the wind
direction) wind turbine and the fixed tower wiring.
The slip-rings and yaw bearings are located just
above the tower mount. The tower mount at-
taches the XL.1 turbine to the top of the tower.
D. Tail Assembly and AutoFurl
The tail assembly, composed of a tail boom and
the tail fin, keeps the powerhead (and, therefore,
the rotor) aligned into the wind at wind speeds
below approximately 12.5 m/s (28 mph). At about

12.5 m/s the AutoFurl action turns the rotor away
from the wind to limit its speed. The tail appears
to fold, but in reality the tail stays stationary as the
powerhead turns sideways to the wind. The rotor
does not, however, furl completely sideways. This
allows the turbine to continue to produce power in
high winds. When the high winds subside the

AutoFurl system automatically restores the tur-
bine to the normal straight position.
E. PowerCenter
The PowerCenter, shown in Figure 3, serves as
the central connection point for the electrical com-
ponents in the system and it provides a number of
necessary and valuable control functions. Not all
of the available functions will be used in all instal-
lations. The PowerCenter also provides status
lights for the system and a handy light-bar "fuel
gage" for the battery bank.
Note
The XL.1 wind turbine will not perform
properly, particularly at low wind
speeds, without the PowerCenter con-
troller. The Power Boost circuitry in the
PowerCenter is needed to provide ac-
ceptable performance in wind speeds
below approximately 7.5 m/s (17 mph).
   
Operation

5. SYSTEM OPERATION

A. Normal Operation
The rotor of the BWC XL.1 should begin to rotate
when the wind speed reaches approximately 3
m/s (7 mph). Battery charging should commence
shortly after the rotor spins up to speed. Once
turning, the rotor will continue to turn in lower wind
speeds, down to approximately 2.5 m/s (6 mph).
The rotor speed will increase with increasing wind
speed and the system will provide a higher output.
This output increases rapidly because the energy
available in the wind varies as the third power
(cube) of the wind speed. For example, if the
wind speed doubles from 5 m/s (11.2 mph) to 10
m/s (22.4 m/s), the energy in the wind increases
Figure 3, PowerCenter for the BWC XL.1
Note
All operational wind speeds given as-
sume steady winds, sea-level altitude
and moderate temperatures. Hot
weather, high altitude, turbulence, and
gusting winds will reduce system per-
formance.
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