BWC EXCEL 1 User manual

BWC EXCEL 1
48 VDC
Battery Charging System
Owner’s Manual
Bergey Windpower Co.
2200 Industrial Blvd.
Norman, OK 73069 USA
Telephone: [phone]
Fax: [phone]
E-mail: [email protected]
Web: www.bergey.com
EXCEL 1 Wind Turbine
Version 1.0
May
2012

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BWC EXCEL 1 Wind Turbine
48V System
OWNER’S MANUAL
TableofContents
1. Overview ..................................................................................................................................................2
2. Cautions and Warnings............................................................................................................................3
3. Identification.............................................................................................................................................4
4. System Description..................................................................................................................................5
5. SYSTEM OPERATION............................................................................................................................7
6. Turbine Installation.................................................................................................................................10
7. PowerCenter Installation........................................................................................................................17
8. Inspections and Maintenance................................................................................................................20
9. Trouble-Shooting Problems ...................................................................................................................23
Appendix .....................................................................................................................................................26
TableofFigures
Figure 1: EXCEL 1 with 60' Tilt Tower.........................................................................................................2
Figure 2: Major Components of the EXCEL 1 Wind Turbine.......................................................................5
Figure 3: AutoFurl ........................................................................................................................................7
Figure 4: EXCEL 1 Basic Electrical Schematic............................................Error! Bookmark not defined.
Figure 5: Tower Mounting for the EXCEL 1...............................................................................................10
Figure 6: Turbine Mounting........................................................................................................................12
Figure 7: Tail Fin Attachment.....................................................................................................................13
Figure 8: Blade and Spinner Fasteners.....................................................................................................14
Figure 9: Nut Tightening Order ..................................................................................................................14
Figure 10: Tail Boom Attachment ..............................................................................................................15
Figure 11: Typical EXCEL 1 System Configuration.....................................Error! Bookmark not defined.
Figure 12: PowerCenter Mounting Dimensions...........................................Error! Bookmark not defined.
Figure 13: PowerCenter with Cover Removed ............................................Error! Bookmark not defined.
Figure 14: Terminals for Electrical Connections..........................................Error! Bookmark not defined.
TableofTables
Table 1: Battery Bank Status Indications.....................................................Error! Bookmark not defined.
Table 2: Variation in wind speed and expected relative energy output with tower height.........................27
Table 3: Recommended Wire Sizes for the EXCEL 1...............................................................................30

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1. Overview
The BWC EXCEL 1-48 wind turbine system is a state-of-the-art small generator designed to charge bat-
teries and supply electrical loads in a 48 VDC power system. When used in conjunction with a suitable
sine wave DC-AC inverter and a 48 VDC battery bank the EXCEL 1-48 can also be connected to the
power grid.
The EXCEL 1-48 turbine consists of an 8.2’, 75 lb wind turbine rated at 1,000 watts, and the Midnite Solar
Classic controller.
The EXCEL 1-48 wind turbine features superior low-wind-speed performance, very high system efficien-
cy, and low noise.
The BWC EXCEL 1-48 is offered with the optional guyed tubular Tilt Tower, which comes in heights from
60’ to 100’. The Tilt Tower is shown in Figure 1. For installation procedures on this tower, please refer to
the “BWC EXCEL 1 Tilt Tower Installation Manual”. This manual is available on-line at
http://www.bergey.com, from BWC dealers, and from BWC directly.
Figure 1: EXCEL 1 with 60' Tilt Tower

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2. Cautions and Warnings
This manual contains important information on the installation of your BWC EXCEL 1 wind turbine and
charge controller. We strongly recommend that you read and follow the instructions contained in
this manual.
At several points in the manual items of special interest or significant impact are highlighted by one of the
following notices.
Warning
Hazards or unsafe practices that could
cause personal injury or death.
Caution
Hazards or unsafe practices that could
cause product damage.
Note
Significant points of interest

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3. Identification
Each BWC EXCEL 1-48 wind turbine has a serial number decal located on the tower mount. The Serial
Number is also written on the box that the turbine came in. We recommend writing it here as well:
BWC EXCEL 1-48 Serial Number :

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4. System Description
EXCEL 1 Wind Turbine Components
The major components of the EXCEL 1 wind turbine are shown in Figure 2.
A. Blades / Rotor System
The rotor system consists of three fiberglass blades. Acting like aircraft wings, the blades convert the
energy of the wind into rotational forces that can drive a generator. The airfoil on the EXCEL 1 is the new
SH3045 developed specifically for the EXCEL 1 by Bergey Windpower. The fiberglass blades are excep-
tionally strong because they are densely packed with glass reinforcing fibers that run the full length of the
blade. The rotor has three blades because three blades will run much smoother than rotors with two
blades.
Blades
Tail Boom
Tail FinPowerhead Alternator
Tower
Mount
Spinner
Nacelle
Figure 2: Major Components of the EXCEL 1 Wind Turbine
B. Alternator
The alternator converts the rotational energy of the rotor into electricity. The alternator utilizes permanent
magnets and has an inverted configuration in that the outside housing (magnet can) rotates, while the
internal windings and central shaft are stationary. The alternator was specially designed for the EXCEL 1
and produces power at low speeds, eliminating the need for a speed-increasing gearbox.
The output from the alternator is three-phase alternating current (AC), but it is rectified to direct current to
charge the battery bank. Since it uses permanent magnets, the alternator is generating voltage whenever
the rotor is turning.
Warning
The output wiring of the BWC EXCEL 1-
48 presents a low voltage shock hazard
whenever the rotor is turning. Caution
must be exercised at all times to avoid
electrical shock.

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C. Nacelle
The nacelle is the fiberglass housing around the main body of the machine. It contains the main structur-
al “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 direc-
tion) wind turbine and the fixed tower wiring. The slip-rings and yaw bearings are located just above the
tower mount. The tower mount attaches the EXCEL 1 turbine to the top of the tower.
D. Tail Assembly and AutoFurlOperation
The tail assembly, composed of a tail boom and the tail fin, keeps the powerhead (and, therefore, the ro-
tor) aligned into the wind at wind speeds below approximately 12.5 m/s (28 mph). At about 12.5 m/s the
AutoFurlaction (see Figure 3) 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 turbine to the nor-
mal straight position.
E. MidNite Solar Classic
The MidNite Solar Classic charge controller is used to charge the batteries. The owner’s manual for the
Classic is included in the Appendix.

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5. SYSTEM OPERATION
A. Normal Operation
The rotor of the BWC EXCEL 1 should begin to rotate when the wind speed reaches approximately 3 m/s
(7 mph). (For the first several weeks of operation, however, the start-up wind speed will be higher be-
cause the bearing seals have not worn-in.) 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 approxi-
mately 2.5 m/s (6 mph).
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.
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 by a factor of eight (23= 2 x 2 x 2 = 8). One result of this relationship is that
there is very little energy available in light winds. For the average site, winds in the range of 5.5 – 9 m/s
(12 – 20 mph) will provide most of the system’s annual energy production.
B. High Winds - AutoFurl
During periods of high wind speeds the AutoFurl system will automatically protect the wind turbine. When
furled, the power output of the turbine will be significantly reduced. In winds between 13 m/s (29 mph)
and 18 m/s (40 mph) it is normal for the turbine to repeatedly furl, unfurl and then furl again. In winds
above 18 m/s (40 mph) the turbine should remain continuously furled.
AutoFurl is a simple and elegant method of providing high wind speed protection. The AutoFurl system is
based on aerodynamic forces on the rotor, gravity, and the carefully engineered geometry of the wind
turbine. As shown in Figure 3, the aerodynamic forces acting on the blades cause a thrust force pushing
back on the rotor. This force increases with increasing wind speeds.
Figure 3: AutoFurl

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The thrust force acts through the centerline of the rotor, which is offset from the centerline of the tower
pivot axis (yaw axis). Therefore, the thrust force on the rotor is always trying to push the rotor over to the
side, away from the wind.
But the rotor is kept facing into the wind at speeds up to ~ 12.5 m/s (28 mph) by the wind turbine’s tail
assembly. The tail, in turn, is kept straight by its own weight because its pivot at the back of the nacelle is
inclined. So the weight of the tail holds it against a rubber bumper and the tail holds the rotor into the
wind.
The geometries in the systems are carefully balanced so that at ~ 12.5 m/s (28 mph) the rotor force acting
on the yaw-offset is large enough to overcome the preset force holding the tail straight. At this point the
rotor will start turning away from the wind or furling. The tail stays aligned with the wind direction. The
speed of furling depends on the severity of the wind gusts and whether the wind turbine stays furled de-
pends on the wind speed.
As the wind turbine furls the geometry of the tail pivot causes the tail to lift slightly. When the high winds
subside the weight of the tail assembly returns the whole turbine to the straight position. The AutoFurl
system works whether the turbine is loaded or unloaded.
The AutoFurl system is completely passive, so it is very reliable and since there are no wear points, like in
a mechanical brake system, it is very robust. AutoFurl was used in the very first wind system produced
by Bergey Windpower in 1980 and in every unit produced since. AutoFurl is an important element of our
success.
There is one situation in the field, however, that we have found can disrupt the operation of AutoFurl. If
the wind turbine is installed on a sharp hill or next to a cliff so that the wind can come up through the rotor
on an incline (e.g., from below; as opposed to horizontally) we know that this will affect furling and can
produce higher peak outputs. We strongly recommend avoiding this situation.
Caution
Do not install the EXCEL 1 wind turbine
near cliffs or precipices or on sharp hills
such that the wind does not travel hori-
zontally through the rotor.
C. Slow-Mode Operation
As the battery bank voltage approaches the battery regulation voltage, the controller will first try to re-
strain this voltage by applying the 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 sufficient, or there is no dump
load in the system, the controller will slow the wind turbine and pulse the solar panels on and off to regu-
late the charge on the batteries.
Slow-Mode prevents the wind turbine from operating without load once the batteries are full. This reduc-
es noise and reduces the likelihood of blade flutter. Blade flutter is loud, short-term, blade vibration that
can occur at very high rotor speeds or in severely gusting winds. Flutter will not hurt the system or en-
danger it, but it can be annoying. Most customers are unlikely to experience blade flutter.
In Slow-Mode, the turbine will be slowed to approximately 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 lim-
ited range as the controller adjusts turbine output current to maintain the battery voltage within a narrow
range. If the load on the batteries increases, dropping battery voltage, the EXCEL 1 will speed up so that
it can deliver more charging current.

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If there is no load at all on the system, then the turbine will be brought to a very slow speed, approximate-
ly 20 RPM, and the solar panels will be disconnected completely.

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6. Turbine Installation
Appendix 1 is an Installation Planning Guide. It provides recommendations on tower heights and loca-
tions, electrical components, and wiring. Please read the Appendix page on “How to Avoid the 6
Most Common Mistakes when Installing an EXCEL 1”.
Tower Mounting: The EXCEL 1 wind turbine is attached to its tower by a three-sided, six fastener cast-
ing, shown in Figure 4, that is designed to fit inside a tube with an inner diameter of 108 mm (4.25 in).
(Note: EXCEL 1’s shipped prior to September 2003 were built to fit a tube with an 85 mm (3.35 in) inner
diameter.)
If you are using the BWC Tilt Tower then the EXCEL 1 will bolt directly in place. If you are mounting the
EXCEL 1 to a different type of tower then you will need to ensure that the tower meets the requirements
for EXCEL 1 towers (see Appendix) and that it has a proper adapter fitting for attaching the EXCEL 1
tower mount casting (also defined in the Appendix).
Once you have the proper mounting arrangement you can proceed with assembly of the wind turbine.
The fasteners on the EXCEL 1 are all metric.
Figure 4: Tower Mounting for the EXCEL 1

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Tilt-up Type Towers: If you have a tilting tower, such as the BWC Tilt Tower, the following proce-
dure is recommended:
Tools Required:
17 mm box end wrench
17 mm socket and ~ 300 mm (12”) ratchet drive
8 mm socket or wrench
pliers
crimpers for wiring terminals (U-shaped crimp preferred over straight crimp)
thread locking compound (like Loctite 242)
tape measure, 12 ft.
Procedure:
Step 1:
With the tower tilted down, place the powerhead of the wind turbine near the top end of the tower.
The tower wiring is connected to the EXCEL 1 wind turbine at the slip-ring using two small screws and
ring terminals crimped to the two conductors. BWC does not supply these ring terminals. Cut the outer
insulation on the wire back about 60 mm (2.5 in). Strip the insulation off the outer 12 mm (1/2 in) of each
conductor and crimp on the appropriate ring terminals. Attach the two power conductors to the slip-ring
assembly with the screws provided. The polarities of the connections are marked. If your conductors are
color-coded we recommend making note of the colors connected to positive and negative leads.
Caution
Do not use the box lugs supplied for the
charge controller connections instead of
ring terminals. The box lugs could short
circuit against the tower tube and dam-
age the alternator.
Caution
Be very careful with the washers on the
slip-ring terminals. DO NOT let them
fall into the alternator. If they do, you
must disassemble the alternator and
remove them before completing the in-
stallation.
The slip ring assembly is not designed to support the weight of the down-tower wire. A strain relieving
installation is required, as shown in Figure 5. If possible put a loop in each wire to wrap around the wire
ties. Use the two nylon cable ties provided to secure the tower wiring to the tower adapter casting. After
completing the connections, pull on the tower wire to make sure that it is secure before mounting the wind
turbine on the tower.
Step 2:
Raise the tower about 3’ off the ground to provide room to assemble the EXCEL 1 turbine. We recom-
mend fashioning a temporary support stand to hold the tower up during turbine assembly.

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Step 3:
Mount the wind turbine tower adapter to the top of the tower using six M10-1.5 x 20mm bolts and six
washers. We require applying Loctite 242 (Thread Locking Compound) to the threads prior to installation
to reduce the likelihood of loosening due to vibration. Use a torque wrench to achieve the proper fastener
torque on the tower mounting bolts. The required torque is 45 ft-lbs.
Power
Cables
Nylon
Cable
Ties
Turbine
Mounting
Bolts
Figure 5: Turbine Mounting
Step 4:
Complete the turbine wiring to the charge controller before adding the blades. This is recommended so
that you can test the DC polarity of the wiring by spinning the alternator by hand. It is very important that
the polarity [positive (+) and negative (-)] is correct when the turbine is connected to the charge controller.
The best way to ensure this is to complete the wiring and then test the polarity with a Volt-Ohm-Meter or
the polarity checker built into the charge controller. Do not use the polarity checker on the charge
controller circuit board with blades on and the turbine turning under wind power because the
voltage will be too high for the polarity check circuitry.
To connect the battery leads, first connect the battery negative (-) wire to the terminal marked “BAT –“.
With the battery positive wire touch the pad marked “POLARITY CHECK”, if red LED (D80) lights, the
connections are backward, double check everything to find the cause. The green LED (D70) should
come on, if it does leave the wire in contact with the “POLARITY CHECK” pad for 5 seconds to charge all
capacitors and avoid a spark when making the battery connection. Quickly connect the battery positive
wire to the terminal marked “BAT +”. The system will not operate correctly and could be damaged if the
polarity is reversed.
Step 5:
Bolt the tail fin to the tail boom using the eight M5 bolts and washers provided, as shown in Figure 6. We
recommend applying Loctite to the bolt threads prior to assembly.

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Tail Fin Fasteners
Figure 6: Tail Fin Attachment
Step 6:
Place the tail boom on the rear of the turbine powerhead and insert the 12 mm (1/2”) tail pivot pin from
the top. If the parts are aligned properly the pin should insert easily. Do not use a hammer to pound the
pin in place, as this may cause scoring of the bronze bushings. Secure the tail pivot pin with two flat
washers and cotter pins, as shown in Figure 9. Note: Failure to properly install and secure both cotter
pins will lead to loss of the tail boom. Let the tail hang down so the turbine head turns part way up for
easier blade assembly.
Step 7:
Turn the EXCEL1 powerhead so that the alternator is facing up. Attach the blades as shown in Figure 7
using the M10 hardware provided. Insert bolts and start all three blade nuts. Then, partially tighten the
nuts in the order shown in Figure 8. We recommend bolting one blade up solidly and leaving the other
two somewhat loose while you check the tip-to-tip blade distance. We recommend checking, and adjust-
ing as necessary, the blade tip spacing to ensure that the blade tips are equally spaced. This step will
help make the wind turbine as smooth running as possible, which will maximize the operating life of the
bearings and reduce vibration related noise. The blade tip-to-tip distances should not differ by more than
1/2” for smooth operation. Finally, torque the nuts (in order shown in Figure 8) to 45 ft-lbs each. Loctite
is not necessary on the blade fasteners because the nylon locking nuts provide adequate locking.
NOTE: For EXCEL 1’s shipped after September 2003, all of the blade bolts are the same length.

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Longer bolt
goes here
Blade Nuts &
Washers
Blade Bolts
Spinner
Fasteners
Figure 7: Blade and Spinner Fasteners
Figure 8: Nut Tightening Order
Step 8:
Attach the spinner (nose cone) using the three M5 bolts and washers provided, as shown in Figure 7. We
recommend applying Loctite to the bolt threads prior to assembly.

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Cotter
Pin
Cotter
Pin
Tail Pivot
Pin
Note: Install M12 Flat Washers
between cotter pins and tail boom.
Figure 9: Tail Boom Attachment
Step 9:
Check the EXCEL 1 wind turbine carefully to make sure that the installation is complete. We recommend
the following checklist:
Blade fasteners are secure and properly torqued
Blade tips are evenly spaced
Spinner is secure
Tail fin is secure
Tail pivot pin is locked in place with both cotter pins.
Tower adapter bolts are secure
Wiring polarity is tested and marked
Step 10:
Dynamically brake the EXCEL 1’s alternator by either of two methods: 1) using the Stop Mode function of
the charge controller, if you already have the turbine and battery bank connected to the charge controller,
or 2) connecting the positive (+) and negative (-) output leads together. The resulting short-circuit will
keep the rotor from spinning during tower raising. DO NOT raise the wind turbine without first stopping
the rotor from turning.
Step 11:
Raise the tower following the procedures outlined by the tower supplier. Please make safety your top
priority.
Non-tilting Towers: On a non-tilting tower, such as a fixed guyed tower or a self-supporting pole
type tower, there are two general approaches that can be used: 1) assemble the tower and turbine to-
gether on the ground and then use a light-duty crane to set the tower in place, or 2) erect the tower and
then lift the wind turbine to the top with either a light-duty crane or a gin-pole.
A gin-pole, in this case, is a tower assembly tool that attaches to the tower and provides an arm with a
pulley so that parts can be hoisted above the top of the tower. Gin-poles are used by professional tower
erectors and we do not recommend their use by non-professionals. We know of at least one homeowner

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who died approximately fifteen years ago while improperly using a gin-pole to install a small wind turbine
(though not a Bergey turbine).
Wherever possible we strongly recommend assembling the tower and turbine on the ground. In this case
please follow the general procedure for turbine assembly provided in the preceding section. When raising
the tower you must lift the tower, not the EXCEL 1 wind turbine. The EXCEL 1 cannot support the weight
of the tower.
For customers installing a BWC EXCEL 1 on an existing fixed tower we recommend that you use a crane
to lower the tower so that you can attach the turbine on the ground. Alternatively, we recommend you
use a bucket-truck, like the type used by utility linemen. Check with local sign companies because they
often offer bucket-truck services at reasonable hourly rates. If neither of these approaches is possible
then we recommend that you engage the services of professional wind turbine or tower erectors to install
your wind turbine.

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7. Charge Controller Installation
A. Electrical System
The general electrical configuration for BWC EXCEL 1 installations will typically involve AC (alternating
current) converting to DC (direct current) power, and they will be used through a connection to the Mid-
night Classic charge controller to charge 48 volt batteries.
The charge controller has a limited current carrying capacity so we recommend that you use a DC Source
Center whenever you have multiple EXCEL 1 wind turbines. DC Source Centers are available from Ber-
gey Windpower and from other sources.
Additional Design Guidance:
1. If you have multiple EXCEL 1 turbines and charge controllers, do not connect more than one wind
turbine to one charge controller.
2. Connect multiple charge controllers to a DC Source Center via the charge controllers’ battery
terminals.
3. Do not connect the charge controller to another controller that could disconnect the charge con-
troller from the batteries. The charge controller should not be disconnected from the battery
when there is input from the wind turbine.
4. Do not connect the charge controller to the batteries through diodes
B. Location
The charge controller must be installed indoors and should be located relatively close to the battery bank.
Do not install the charge controller outdoors; it is not waterproof.
C. Mounting
The charge controller needs to be mounted vertically to a wall, or other support structure, so that air can
pass unobstructed through the passive cooling channel behind the enclosure. We recommend setting the
height of the readout at eye level if possible so that the system status will be easiest to read.
The enclosure dimensions and mounting layout for the charge controller are shown in Error! Reference
source not found.. The charge controller should be mounted with four M4 (0.157” dia.) screws. We rec-
ommend the following procedure:
Tools Required:
Pencil
Carpenters level
Drill with ~ 2 mm or 0.09” dia. drill bit
(4) M4, 1/8”, or 5/32” screws
Screwdriver
Procedure:
Step 1:
Mark the mounting hole locations using the charge controller enclosure as the template. Use a carpen-
ters level to check the levelness of the enclosure before marking the holes.
Step 2:
Drill small (~ 2.5 mm or 0.1 in diameter) pilot holes for the mounting screws.
Step 3:

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Screw the top two mounting fasteners into the wall until ~ 6 mm (1/4”) of the shank extends out from the
wall.
Step 4:
Remove the charge controller cover and place the charge controller enclosure on the two upper mounting
fasteners. Slide the enclosure down such that the fasteners are placed at the top of the inverted “T-slots”.
Step 5:
Install the bottom two mounting fasteners, and then tighten the top two fasteners.
D. Wiring
All wiring should conform to the National Electric Code or other governing local electrical code. The use
of electrical conduit for wiring between components is highly recommended. If you have any connections
with dissimilar metals (aluminum to copper) they should be coated with an anti-oxidation compound to
prevent galvanic corrosion. All loads should be protected by fuses or circuit breakers to avoid hazards
from accidental short circuits.
The wind turbine tower must be well grounded and a good quality lightning surge arrestor, connected to a
good quality earth ground, should be installed on the wiring from the wind turbine. We recommend a Del-
ta LA302DC arrestor installed into the third (from the left) rear entrance hole of the enclosure. This tucks
the arrestor neatly behind the enclosure. The arrestor leads are connected to the wind turbine terminals.
The charge controller does not have a built in ground, all circuits are floating, such that either the positive
or the negative can be grounded. Some inverter manufacturers recommend grounding and some electri-
cal codes require it. If you do ground the charge controller, please conform to local practices for ground-
ing either the positive or negative bus.
All negative leads are connected together on the charge controller circuit board, so grounding the battery
negative lead, will ground the turbine negative, the PV negative, and the dump load negative as well.
This is the preferred grounding method; the enclosure should also be grounded, by bolting a box lug to it
in a convenient location.
E. Charge Controller Connections
Cable Entrances: As shown in Error! Reference source not found., wiring can be connected to the
charge controller from below or behind or in a combination of both. A total of eighteen 7/8” (20 mm) en-
trance holes are provided.
Box Lugs: The charge controller is supplied with box lugs (not shown in Error! Reference source not
found. and Error! Reference source not found.) that are used to connect electrical leads to the terminals
on the charge controller circuit board. These lugs can accommodate wire sizes from 35 mm2to 10 mm2
(8 AWG to 2 AWG). DO NOT use these lugs for the wiring connections to the wind turbine at the
top of the tower.
Plastic Grommets and Plugs: The charge controller is supplied with a number of plastic grommets and
plugs for the wire entrance holes at the bottom of the enclosure. Grommets should be used to protect
incoming wires from the hard edge of the aluminum case. They are not necessary if you are using con-
duit or special cable entrance fittings. Holes not used for wiring should be sealed using the plastic plugs.
Even though 48 VDC is generally not considered a lethal voltage, most electrical codes will require that
the unused entrance holes be sealed and we believe that this is the prudent and safest course of action.

19
We recommend the electrical connections be made in accordance with the charge controller owner’s
manual, which is attached in the Appendix. Please ensure that the wires do not pull on, or flex, the cir-
cuit board.
The EXCEL 1 wind turbine system is now ready to operate. We recommend that you verify that the EX-
CEL 1 is producing power by putting the charge controller in Watt Display mode. In all but the lightest of
winds, you should see indication of varying wattage coming from the wind turbine.