User manual VAISALA WAA252 QUICK REFERENCE GUIDE PART 1

[. . . ] 60 m/s) with characteristic transfer function ± 0. 17 m/s 2) with transfer function Uf = 0. 1 × R ­0. 3/+1. 0 m/s 3) Input power 24 VDC ± 10 %, 3. 2 A max. Typical power consumption 72 W below +2 °C (heating on) (Uin = 24 VDC) 1 W above +6 °C (heating off) Optional xducer i/p power (Uxdr) 4. 8 - 15. 3VDC, 11mA typ. Transducer output high level > 11 V (or > Uxdr - 1. 5V) (with Iout < +5 mA) Transducer output low level < 1. 5 V (with Iout > ­5 mA) Output power for wind xmitters 13 ± 1 VDC, 75 mA max. Electrical connections MIL-C-26482 type 6-pin plug Operating temperature ­55 . . . [. . . ] The WAA252 can even deliver an isolated 12V excitation to a separate wind transmitter, if needed. Optionally it is possible to take the transducer power from an external device such as the WT521 or WAT12 wind transmitter. This guarantees an uninterrupted transducer supply, independent of the heating power. The WAA252 can be mounted on Vaisala's regular WAC151 crossarm and its output interface is compatible with that of the regular WAA151 anemometer. Therefore, updating to a heated-cup system is easy - just a wiring alteration is needed in the crossarm's junction box. Wind tunnel tests per ASTM method D5096-90 have been conducted on the WAA252 in order to define its aerodynamical behavior. The WAA252's power inputs and signal outputs are well protected against line transients and interference. The device itself emits no unacceptable electro-magnetic noise to the signal cables or the atmosphere. www. vaisala. com Mounting and Locating In mounting the WAA252 Heated Anemometer keep in mind the recommendations for locating the wind sensors. Following three cases are most typical: 1 Preferred location is on the top of a mast, at a site with open terrain. The recommendation is to have at least 150 m open area in all directions. Minimum distance to visible obstacles is 10 times the height of the obstacle. When the gauge is mounted beside the mast, the distance from the mast to the crossarm should be at least 3 times the diameter of the mast. If mounted on the top of the building, the gauge should be installed on top of a mast at least 1. 5 times as high as is the height or the largest width of the building, whichever is smaller. NOTE Following the recommendations for locating the wind sensors is essential for receiving reliable wind data. 2 3 Electrical The WAA252 operates from a single 25 VDC +10% power supply, at 3. 2-ampere maximum current (@ 25 V). Most of the current is consumed by the heating, typically enabled only at ambient temperature below +5 °C. WAA252 Connector A F+ Optional power input for transducer section, 5. . . 15VDC, 10mA typ. Signal Ground (also GND for optional power i/p and o/p at A and F) Signal Output, 0. . . 750Hz square wave (for 0. . . 75m/s), (HI>11V / LO<1V typ. ) Power Ground Power Input, 24VDC +10%, 3. 2 A max. Optional power output for external transmitter, 13VDC typ. , 75 mA max. The input power supply leads are connected to the terminals E(+) and D(-) of the I/O connector (presented in Table 1). The lead diameter should be such that no excessive power is wasted in the cable. Each 0. 3 ohms in the cable will cause a 1-Volt extra drop in the operational voltage, which in turn will decrease the applicable heating power. [. . . ] The power cable leads (ZZ45049 or equivalent) are applied to the terminals #2(+) and #3(-). In case the installation includes both the WAA252 and WAV252, the power line current exceeds 5 A. Hence a large wire dimension or several wires in parallel shall be used. Each 0. 2 ohms in the power cable will cause a 1-volt extra drop in the input voltage, which in turn will decrease the available heating power. [. . . ]