45 Foot Air Guyed Tower Kit

PRIMUS WIND POWER Page 7 of 26
2/4/05
PRIMUS WIND POWER DOCUMENT #0070 REV C
The other concern with long wires is the voltage drop through the wire. Voltage drop through the
wires can be calculated using the formula:
Voltage = Current x Resistance
The effect of the voltage drop is most apparent when the turbine has good wind and is actively
charging the batteries. The regulator in the turbine, which senses battery voltage, will measure the
combined voltage drop from the batteries and from the current passing through the resistance of the
wires. This causes the turbine to sense a higher voltage than that of the batteries and regulate its
power accordingly to prevent overcharging. When this happens the turbine will not fully charge the
batteries. Adjusting the regulation set point of the turbine to compensate for this at higher wind
speeds can cause the turbine to overcharge the batteries in lighter wind conditions. If a long
distance between the tower and batteries is necessary, using a large wire size will help to address
this issue. The person laying out your power system should be aware of these considerations when
the system is in the planning stages.
Please refer to the section on “Tower, Base and Anchor Layout”. The amount of space available to
assemble and raise the tower may also affect where your tower can be placed
Step 2: Mast and Hardware Selection
Due to the high cost of shipping and the widespread availability of the tubing or pipe used for our
towers, these materials are not provided by Primus Wind Power. These materials are readily
available through most fence suppliers or plumbing companies and will cost much less when
purchased locally than if we were to try to ship them from our factory.
The “AIR” wind turbine is designed to be mounted on a 1.875 in. outside diameter pole. This is the
same outside diameter as 1 ½ in. steel water pipe where the “1 ½” is a nominal size indicating an
outside diameter that is actually 1.875 in. Whether the pipe is “schedule 20”, or “schedule 40”, the
outside diameter will be the same and the schedule number will determine the wall thickness of the
pipe. If you planning an “UL-certified” installation, only schedule 40 (thicker pipe wall) pipe is
suitable for the installation. If the pipe is lighter than “schedule 20”, it is referred to as “tubing”,
and the actual outside diameter and wall thickness are usually specified. Use only structural steel
tubing for this tower! Consider using only galvanized pipe for this application, since your tower is
likely to deteriorate in the outdoors if it is not protected from elements. If a galvanized pole is not
preferred, then a rust inhibitor (outdoor paint or grease) is highly recommended on the pipe and
other critical components.
The design of this tower kit allows steel pipe (or tubing) of various different wall thickness to be
used depending on its availability and on the severity of the wind at your site location.
Use the following table to determine the acceptable pipe size(s) for your tower and wind severity.
In most locations structural steel tubing with a wall thickness of .065 inches is sufficient for the
conditions and preferable in terms of cost and ease of assembly. Electrical conduit should be
avoided for use in your tower assembly, since it is generally not designed for strength.