Specifications

5
optional Extra Load (or “dump load”). The Extra
Load function diverts current from the battery to
an air or water heater. If this measure is not suffi-
cient, or there is no dump load in the system, the
PowerCenter will slow the wind turbine and pulse
the solar panels on and off to regulate the charge
on the batteries.
Slow-Mode prevents the wind turbine from operat-
ing without load once the batteries are full. This
reduces noise and reduces the likelihood of blade
flutter. Blade flutter is loud, short-term, blade vi-
bration that can occur at very high rotor speeds or
in severely gusting winds. Flutter will not hurt the
system or endanger it, but it can be annoying.
Most customers are unlikely to experience blade
flutter.
In Slow-Mode, the turbine will be slowed to ap-
proximately 130 RPM in low wind speeds, and as
the wind speed increases, the operating RPM will
be decreased. Maximum power in this mode is
120 watts and the power output will decrease as
the wind speed decreases. The speed of the rotor
will vary over a limited range as the PowerCenter
adjusts turbine output current to maintain the bat-
tery voltage within a narrow range. If the load on
the batteries increases, dropping battery voltage,
the XL.1 will speed up so that it can deliver more
charging current. .
If there is no load at all on the system, then the
turbine will be brought to a very slow speed, ap-
proximately 20 RPM, and the solar panels will be
disconnected completely.
D. PowerCenter Controller
The basic electrical schematic for the BWC XL.1
is shown in Figure 5. The XL.1’s alternator pro-
duces three-phase alternating current (AC) that
varies in voltage and frequency with the rotor
speed. The AC power is rectified to direct current
(DC) power by a rectifier module inside the na-
celle. Thus, the wire run from the wind turbine to
the PowerCenter is DC.
Alternator
Rectifier
(on turbine)
DC Wire Run
PowerCenter
Optional Dump Load
Battery Bank
Optional
Solar
Array
Figure 5, XL.1 Basic Electrical Schematic
The PowerCenter for the XL.1 has two sets of
color-coded light-emitting-diodes (LED’s) for Sys-
tem Status and Battery Bank Status.
System Status Lights:
Solar Power (green): Lights up when the op-
tional solar panel(s) are charging the batteries.
Extra Load (red): Lights up when the optional
auxiliary or dump load is activated as the batte-
ries approach full charge. When the red LED
is lit, the dump load will be heating.
Wind Power (green): Lights up when the XL.1
wind turbine is charging the batteries. A blink-
ing green LED indicates that the low wind
speed performance optimizing circuitry (low
end boost) is operating.
Slow Mode (yellow): Blinks slowly to indicate
that the turbine is being operated slowly to pre-
vent overcharge of the batteries, or because
Slow Mode has been manually selected. If
pressing the mode selector button has manual-
ly stopped the turbine, this LED will blink rapid-
ly, the turbine may still be spinning, but will be
stopped as soon as possible. In “Blown Fuse
Mode” this LED blinks every second, the same
frequency as the Wind Power LED.
Battery Bank Status Lights:
Battery bank charge status is shown with ten co-
lored LED’s, which act like a fuel gage for your
remote power system. This gage, however, is
inexact and it is intended to provide only a general
indication of the energy reserves available in the
system. The following table shows the voltage
indicated by the highest lit LED and its approx-
imate relationship to the battery capacity availa-
ble.