Version 2.3 January 2012 BWC EXCEL 1 24 VDC Battery Charging System Owner’s Manual EXCEL 1 Wind Turbine PowerCenter Controller Bergey Windpower Co. 2200 Industrial Blvd. Norman, OK 73069 USA Telephone: (405) 364-4212 Fax: (405) 364-2078 E-mail: sales@bergey.com Web: www.bergey.
BWC EXCEL 1 Wind Turbine 24V Battery Charging System OWNER’S MANUAL Table of Contents 1. Overview .................................................................................................................................................. 2 2. Cautions and Warnings ............................................................................................................................ 3 3. Identification ...............................................................................................
1. Overview The BWC EXCEL 1-24 wind turbine system is a state-of-the-art small generator designed to charge batteries and supply electrical loads in a 24 VDC DC-bus based remote power system. When used in conjunction with a suitable sine wave DC-AC inverter and a 24 VDC battery bank the EXCEL 1-24 can also be connected to the power grid. The EXCEL 1-24 turbine consists of an 8.2’, 75 lb wind turbine rated at 1,000 watts, and a multi-function turbine and system controller: the PowerCenter.
2. Cautions and Warnings This manual contains important information on the installation of your BWC EXCEL 1 wind turbine and PowerCenter 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.
3. Identification Each BWC EXCEL 1-24 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.
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.
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.
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 because 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 approximately 2.5 m/s (6 mph).
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.
If there is no load at all on the system, then the turbine will be brought to a very slow speed, approximately 20 RPM, and the solar panels will be disconnected completely. D. PowerCenter Controller The basic electrical schematic for the BWC EXCEL 1 is shown in Figure 5. The EXCEL 1’s alternator produces 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 nacelle.
Table 1: Battery Bank Status Indications LED No. (from left side) L1 (red) Indicated Battery Voltage Range Below 22 V Approximate Battery Reserve Below 5% L2 (yellow) 22 – 23.5 V 5% L3 (green) 23.5 – 24 V 15% L4 (green) 24 – 24.5 V 30% L5 (green) 24.5 – 25 V 60% L6 (green) 25 – 27 V 90% L7 (green) 27 – 28 V 100% L8 (green) 28 – 29.5 V 100% L9 (yellow) 29.5 – 30.5 V 100% L10 (red) Above 30.5 V 100% The LED’s provide an indication of the instantaneous battery voltage.
Using the PowerCenter Functions (Modes) Stopping the Turbine The rotor can be stopped under most wind conditions using the electrical braking function in the PowerCenter. You might use this function, for example, before lowering or climbing the tower. We do not recommend frequent use of the braking function because of the heat stress it puts on the alternator, particularly when the winds are strong.
Manual Slow Mode: Normal operation can be overridden and the turbine forced to operate very slowly, but still produce some power using the manual Slow-Mode function. To select this mode press and hold the mode selector button until the Slow-Mode LED begins blinking slowly and release. To exit Slow-Mode, press (click) the Mode Selector Button. To manually exit manual or automatic Slow Mode, click the Mode Selector Button.
If the battery voltage rises above regulation voltage the Extra Load (dump load) circuit is ramped up to control the battery voltage. The maximum allowable resistance load that can be placed on the dump load circuit is 0.5 ohms, producing a maximum current of 60 amps. When the EXCEL 1 and the solar are producing more output than the batteries and dump load will accept, then the PV will be turned off. If the battery voltage continues to rise then the turbine will be put into Slow-Mode operation.
Warning FIRE HAZARD DO NOT use a dump load that is not safely isolated from all potential sources of combustible materials or fuels, including wood mounting boards and hydrogen out-gassing from the batteries. Put another way a dump load rated 60 amps at 30 volts is the largest that can be used. Multiple loads can be connected in parallel as long as the sum of their individual currents does not exceed 60 amps. Due to the PWM feature some Extra Loads may be noisy.
6. Turbine Installation Appendix 1 is an Installation Planning Guide. It provides recommendations on tower heights and locations, 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 casting, shown in Figure 6, that is designed to fit inside a tube with an inner diameter of 108 mm (4.25 in).
Tilt-up Type Towers: If you have a tilting tower, such as the BWC Tilt Tower, the following procedure 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.
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.
See “PowerCenter Connections” beginning on Page 14. Step 5: Bolt the tail fin to the tail boom using the eight M5 bolts and washers provided, as shown in Figure 8. We recommend applying Loctite to the bolt threads prior to assembly. Tail Fin Fasteners Figure 8: 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.
Spinner Fasteners Blade Nuts & Washers Longer bolt goes here Blade Bolts Figure 9: Blade and Spinner Fasteners Figure 10: Nut Tightening Order Step 8: Attach the spinner (nose cone) using the three M5 bolts and washers provided, as shown in Figure 9. We recommend applying Loctite to the bolt threads prior to assembly.
Note: Install M12 Flat Washers between cotter pins and tail boom. Tail Pivot Pin Cotter Pin Cotter Pin Figure 11: 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.
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.
7. PowerCenter Installation A. Electrical System The general electrical configuration for BWC EXCEL 1 and hybrid system installations is shown in Figure 12. In most cases the loads will be AC (alternating current) and they will be supplied through a DC-to-AC inverter.
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 PowerCenter enclosure as the template. Use a carpenters 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 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.
Figure 14: PowerCenter with Cover Removed We recommend the following procedure for making the electrical connections. Please ensure that the wires do not pull on, or flex, the circuit board. Step 1: Remove the cover to expose the circuit board and terminals. The terminals are on the circuit board, as shown in Figure 15. Figure 15: Terminals for Electrical Connections Step 2: Connect Dump Load leads. This is an optional resistance-heating load that will operate when the batteries are full.
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. The maximum current to the batteries will be ~ 60 amps with no PV and up to ~ 90 amps with the maximum allowed PV array size. Wiring to the batteries must be sized accordingly (minimum 25mm2, 4 AWG) Step 4: Connect Wind Turbine leads.
Step 7: Connect Loads. If the system includes 24 VDC loads, connect them to the battery terminals or DC source center. Do not connect them directly to the PowerCenter. Step 8: Click the mode selector button to release the turbine, and begin operating the turbine. The EXCEL 1 wind turbine system is now ready to operate. We recommend that you verify that the EXCEL 1 is producing power by putting the PowerCenter in Watt Display mode (see Page 7).
8. Inspections and Maintenance The BWC EXCEL 1 installation should be inspected after 30 days and then again 180 days after installation. Following these two inspections the installation should be inspected every two years and after any particularly severe weather. In corrosive marine environments more frequent inspections are recommended. Inspections should be done on days when the wind is below 7 m/s (16 mph). Check List for Inspections 1. Inspect each of the anchor points.
10. Check the connection on all ground rods and hardware. 11. Inspect the surge arrestor(s). Replace if there are signs of damage. 12. Restart the turbine. 13. Listen to the sound of the machine as it speeds up. No mechanical sounds, such as a "clunking" or "banging," should be heard. Also watch for any new or significant vibration. Some “growling” from the alternator is normal. The turbine operation should be smooth. 14. Inspect the wire run, particularly all electrical connections. 15.
The strength of the blades, particularly at the root (inner) end, may degrade over time due to flexure and UV degradation of the fiberglass material. The symptom of degradation is a reduction in blade stiffness fore-and-aft. The blades have to become very flexible in the fore-aft direction before there is any risk of tower strikes during severe weather. We recommend that you check blade stiffness about every 10 years and replace the blades if they become extremely flexible.
9. Trouble-Shooting Problems The following guide can be used to pinpoint the cause of operational problems with the BWC EXCEL 1 wind turbine and the PowerCenter controller. For problems or symptoms not found in the following listing, please contact the Service Department at Bergey Windpower Co. at: Tel: 405-364-4212 Fax: 405 364-2078 e-mail: service@bergey.com Problem Battery voltage gets too high.
Problem Rotor turns, but the system doesn’t charge the batteries. Cause(s) Blown Turbine fuse Blown output fuse Power transistor failure. Rotor is unbalanced, causing the turbine to move slightly back and forth as it spins. Wind is higher than 16 mph, but rotor will not turn, or turns slowly Turbine rectifier failure, possible damaged stator winding Blade tips not evenly spaced. Remedy Replace fuse Check tip-to-tip distances with a tape measure. They should be within 6.5 mm (¼”).
Problem PV is not on, even though sun is shining. Dump load does not work. Cause(s) Dump load at 97% capacity or higher PV hooked up backwards. PV fuse blown. Fuse blown. Voltage below regulation. Dump load comes on during automatic generator charge, preventing the batteries from taking a bulk charge 33 Dump load set to come on at 28.1 Volts, Inverter set to bulk charge batteries at a higher voltage Diagnosis Turn on additional loads to pull down battery voltage. See if PV turns on. Check polarity.
Appendix Installation Planning The location and height of the tower for the BWC EXCEL 1 wind system will be important factors in determining the overall performance of the system. Average wind speed is influenced by many things and may vary considerably within a relatively small region, particularly in complex terrain. Site and tower choice, however, are often limited by such factors as zoning restrictions, property size, proximity to neighbors, customer preferences, and wiring costs.
way you would like to be treated and showing respect for their views. An example of what not to do is to put the turbine on your property line so that it is closer to a neighbor’s house than to your own and not give those neighbors any advance notice of your intentions. In general, we do not recommend that a BWC EXCEL 1 be installed on property of less than one-half acre in size.
tem are substantial and homes are not designed structurally for them, 2) the air flow around and over a home or building is complex and can cause considerable turbulence, and 3) the wind turbine will cause vibrations that will be amplified through the home’s structure. BWC offers a guyed-tubular tilt-up tower, the Tilt Tower, for the EXCEL 1 in heights form 9 m (30 ft) to 32 m (104 ft). The Tilt Tower is cost-effective and is designed to be installable by non-experts.
5. Safety The BWC EXCEL 1 should never be installed close to a power line. We recommend that the tower be at least 1 ½ times the height of the tower from any power line including any overhead service line bringing power to your home. Warning The wind turbine towers are typically made of metal, which readily conducts electricity. If any part of the wind turbine or tower makes contact with power lines there is a risk of electrocution.
Table 3: Recommended Wire Sizes for the EXCEL 1 WIRE SIZE MM^2 AWG 10 8 AWG 16 6 AWG 25 4 AWG 30 3 AWG 35 2 AWG 50 1 AWG 55 1/0 AWG 70 2/0 AWG 95 3/0 AWG 120 4/0 AWG DISTANCE FROM TURBINE TO POWERCENTER METERS 0 - 35 36 - 56 57 - 89 90 - 112 113 - 141 142 - 178 179 - 225 226 - 287 288 - 361 362 - 455 FEET 0 - 116 117 - 183 184 - 292 293 - 368 369 - 464 465 - 585 586 - 739 740 - 940 941 - 1185 1186 - 1494 Note: These wire sizes have been engineered to provide optimum rotor loading for the BWC EXCEL 1/24 w
39 Setting the low voltage disconnect (typically part of the inverter) too high so that the battery bank capacity is underutilized
How to Avoid the 6 Most Common Mistakes When Installing an EXCEL 1 1. DO NOT use the PowerCenter box lugs to connect wiring to the turbine. There is not enough space for them, so they will rub the tower and eventually develop a short circuit. Use crimp-type ring lugs. Use These Not These 2. DO use the built-in polarity checker when connecting the battery leads to the PowerCenter. Connect either battery lead to the Neg.
EXCEL 1 SPECIFICATIONS TURBINE: ROTOR DIAMETER OVERALL LENGTH TURBINE WEIGHT TURBINE THRUST RATED POWER RATED WINDSPEED RATED ROTOR SPEED START-UP WINDSPEED CUT-IN WINDSPEED FURLING WINDSPEED MAX DESIGN WINDSPEED MAX RUNNING CURRENT MAX SHORT CIRCUIT CURRENT 8.2 FT 6.9 FT 75 LB 200 LB 1,000 W 11 M/S 24.6 MPH 490 RPM 3 M/S 6.7 MPH 2.5 M/S 5.
BASIC TOWER REQUIREMENTS For the BWC EXCEL 1 Wind Turbine Customer supplied towers for the BWC EXCEL 1 Wind Turbine should meet the following minimum 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.
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