Vaisala WAA151 User manual

M210293EN-C
User Guide
Vaisala Anemometer
WAA151

PUBLISHED BY
Vaisala Oyj
Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland
P.O. Box 26, FI-00421 Helsinki, Finland
[phone]
Visit our Internet pages at www.vaisala.com.
© Vaisala Oyj 2018
No part of this document may be
reproduced, published or publicly
displayed in any form or by any
means, electronic or mechanical
(including photocopying), nor
may its contents be modified,
translated, adapted, sold or
disclosed to a third party without
prior written permission of the
copyright holder. Translated
documents and translated
portions of multilingual
documents are based on the
original English versions. In
ambiguous cases, the English
versions are applicable, not the
translations.
The contents of this document are
subject to change without prior
notice.
Local rules and regulations may
vary and they shall take
precedence over the information
contained in this document.
Vaisala makes no representations
on this document’s compliance
with the local rules and
regulations applicable at any
given time, and hereby disclaims
any and all responsibilities related
thereto.
This document does not create
any legally binding obligations for
Vaisala towards customers or end
users. All legally binding
obligations and agreements are
included exclusively in the
applicable supply contract or the
General Conditions of Sale and
General Conditions of Service of
Vaisala.

Table of Contents
1. About This Document...................................................................................... 3
1.1 Version Information.............................................................................................3
1.2 Related Manuals...................................................................................................3
1.3 Documentation Conventions..............................................................................3
1.4 Trademarks...........................................................................................................4
2. Product Overview.............................................................................................. 5
2.1 Vaisala Anemometer WAA151............................................................................ 5
2.2 Safety.................................................................................................................... 5
2.2.1 ESD Protection..............................................................................................6
2.3 Regulatory Compliances.....................................................................................6
3. Installation............................................................................................................ 7
3.1 Selecting Location............................................................................................... 7
3.2 Mounting Wind Sensors on Cross Arm........................................................... 10
3.3 Connecting the Anemometer............................................................................ 11
3.4 Verifying Installation........................................................................................... 11
4. Maintenance........................................................................................................12
4.1 Cleaning the Anemometer................................................................................ 12
4.2 Testing Anemometer Operation.......................................................................12
4.3 Replacing Consumables.................................................................................... 12
4.4 Reassembling the Anemometer.......................................................................14
5. Troubleshooting................................................................................................16
6. Technical Data....................................................................................................17
6.1 WAA151 Specifications.......................................................................................17
6.2 Spare Parts and Accessories.............................................................................19
6.3 MTBF....................................................................................................................19
6.4 MTTR...................................................................................................................20
Technical Support............................................................................................ 21
Warranty and Product Returns..................................................................... 21
Recycling............................................................................................................ 21
Table of Contents
1

WAA151 User Guide M210293EN-C
2

1. About This Document
1.1 Version Information
Table 1 Document Versions
Document Code Date Description
M210293EN-C November 2018 Updated spare part descriptions of ZZ45037
and ZZ45037SPEC.
M210293EN-B August 2018 Installation instructions updated. Connector
type and item code changed.
M210293EN-A April 2002 First version
1.2 Related Manuals
Table 2 Related Manuals
Document Code Name
M210349EN Vaisala Cross Arm WAC151 User Guide
M210294EN Vaisala Wind Vane WAV151 User Guide
M210822EN Vaisala Serial Wind Transmitter WAC155 User Guide
1.3 Documentation Conventions
Warning alerts you to a serious hazard. If you do not read and
follow instructions carefully at this point, there is a risk of injury or even death.
WARNING!
Caution warns you of a potential hazard. If you do not read and
follow instructions carefully at this point, the product could be damaged or
important data could be lost.
CAUTION!
Note highlights important information on using the product.
Chapter 1 – About This Document
3

Tip gives information for using the product more eciently.
Lists tools needed to perform the task.
Indicates that you need to take some notes during the task.
1.4 Trademarks
Vaisalaâis a registered trademark of Vaisala Oyj.
All other product or company names that may be mentioned in this publication are trade
names, trademarks, or registered trademarks of their respective owners.
WAA151 User Guide M210293EN-C
4

2. Product Overview
2.1 Vaisala Anemometer WAA151
1Cup wheel assembly
2Sensor shaft
3Lower body
WAA151 is a fast-response, low-threshold anemometer. Three lightweight, conical cups
mounted on the cup wheel provide a linear response rate over the entire operating range, up
to 75 m/s (168 mph).
A wind-rotated chopper disc attached to the shaft of the cup generates a pulse output from a
phototransistor in the base of the sensor. The output pulse rate is directly proportional to wind
speed.
The heating element in the shaft tunnel keeps the temperature of the bearings above the
freezing level in cold climates. The nominal heating power is 10 W. Vaisala recommends that
you use a thermostat switch in the cross arm for switching the heating power on below +4 °C
(+39 °F).
2.2 Safety
The WAA151 anemometer delivered to you has been tested for safety and approved as shipped
from the factory. Note the following precautions:
Ground the product and verify outdoor installation grounding
periodically. Failure to provide proper grounding can result in injury or death
from electrical shock and can severely damage the equipment.
WARNING!
Chapter 2 – Product Overview
5

Improper modification can damage the product or lead to
malfunction. Any modification voids your warranty.
CAUTION!
2.2.1 ESD Protection
Electrostatic Discharge (ESD) can damage electronic circuits. Vaisala products are adequately
protected against ESD for their intended use. However, it is possible to damage the product by
delivering electrostatic discharges when touching, removing, or inserting any objects in the
equipment housing.
To avoid delivering high static voltages to the product:
• Handle ESD-sensitive components on a properly grounded and protected ESD workbench
or by grounding yourself to the equipment chassis with a wrist strap and a resistive
connection cord.
• If you are unable to take either precaution, touch a conductive part of the equipment
chassis with your other hand before touching ESD-sensitive components.
• Hold component boards by the edges and avoid touching component contacts.
2.3 Regulatory Compliances
WAA151 complies with the following performance and environmental test standards:
WAA151 User Guide M210293EN-C
6

3. Installation
3.1 Selecting Location
Finding a suitable site for the product is important for getting representative ambient
measurements. Make sure that the site represents the general area of interest.
Allow sucient clearance for the wind sensors. Do not install wind sensors next to
a building or any other object that can aect the flow of air.
Installations on top of high buildings or masts and in sites on open
grounds are vulnerable to lightning strikes. A nearby lightning strike may induce
a high-voltage surge not tolerable by the internal surge suppressors of the
instrument. Additional protection is needed in regions with frequent, severe
thunderstorms, especially when long line cables (>30 m (98 ft)) are used.
Vaisala recommends using a surge protector, such as WSP150, in all sites with an
elevated risk of a lightning strike.
CAUTION!
Chapter 3 – Installation
7

Figure 1 Recommended Mast Location in Open Area
Any object of height (h) does not remarkably disturb wind measurement at a minimum
distance of 10 × h. There must be at least 150 m (500 ft) open area in all directions from the
mast. Minimum distance between the mast and obstacles is ten times the height of an
obstacle.
WAA151 User Guide M210293EN-C
8

Figure 2 Recommended Mast Length on Top of Building
The recommended minimum length (h) for the mast that is installed on the top of a building is
1.5 times the height of the building (H). When the diagonal (W) is less than the height (H) the
minimum length of the mast is 1.5 × W.
Chapter 3 – Installation
9

3.2 Mounting Wind Sensors on Cross Arm
• 2-mm Allen key
• Compass
1. Fit the cable plug through the mounting flange at the end of the cross arm, and connect
the cable to the sensor.
1Plastic washer
2Hex screw
2. Insert the plastic washers between the flange and the sensor.
3. Face the sensor product label South, if possible, and mount the sensor to the flange by
twisting.
4. Tighten the screws.
5. Mount the assembly and tighten the fixing screw.
WAA151 User Guide M210293EN-C
10

3.3 Connecting the Anemometer
Figure 3 WAA151 Connector Sensor Side
AF+, power input from 9.5 to 15.5 VDC
BGND, common ground
CFout, signal output
DHTNG, 20 VDC or VAC
EHTNG, 20 VDC or VAC
FNot connected
Vaisala recommends using the SOURIAU UTS6JC10E6P cable connector for the
cable side of this sensor.
Figure 4 WAA151 Connector Cable Side
1. Connect the heating element in the shaft tunnel between pins D and E.
2. Supply the heating element with 20 VDC or VAC.
3.4 Verifying Installation
1. Make sure that the sensor is powered up and connected to the data collection system.
2. Rotate the cup wheel manually and make sure the speed readings change.
Chapter 3 – Installation
11

4. Maintenance
4.1 Cleaning the Anemometer
Heavy contamination in the cups, such as bird droppings or ice, deteriorates the anemometer
accuracy. Clean the cups when contaminated.
4.2 Testing Anemometer Operation
The sensor holds its accuracy in all conditions for 1 year. If the rains are mostly casual and
moderate, and the atmospheric corrosion is typical, the sensor accuracy remains for 2 years.
Check the ball bearings and rotate the sensor shaft once a year.
1. Remove the cup wheel.
2. Make sure that the shaft spins smoothly and that there is no noise.
4.3 Replacing Consumables
Only a trained technician may replace the bearings.
WAA151 User Guide M210293EN-C
12

1O-ring (2 pcs)
2Chopper disc
3External retaining ring, body
4Spacer ring
5Internal retaining ring, shaft
6Shaft and upper body assembly
7Cup wheel assembly
8Ball bearings
9Ball bearings
10 Printed circuit board (PCB)
11 Spacer (3 pcs)
12 Lower body
13 M6x16 DIN7991 (3 pcs)
14 Hex nut of the connector
Chapter 4 – Maintenance
13

1. Open the cup wheel fixing screw with a 2-mm Allen key. Remove the cup wheel assembly.
Do not remove the fixing screw to ensure perfect sealing after
reassembling. The fixing screw has been treated with sealant.
CAUTION!
2. Loosen the hex nut of the connector with a 22-mm tool.
Be careful not to bend the connector pins.CAUTION!
3. Loosen the three pan head screws at the bottom of the sensor body with a 7-mm tool.
4. Remove the lower body assembly by pulling it straight outwards.
5. Loosen the spacer screws with a 7-mm tool and disconnect the heating element outlet.
6. Remove the printed circuit board including the opto-coupler.
Do not twist or bend the connector. This may break the pins.CAUTION!
7. Loosen the fixing screw of the chopper disc with a 2-mm Allen key and remove the
chopper disc.
8. Remove the external retaining ring with narrow-pointed pliers.
9. Remove the spacer ring.
10. Remove the internal retaining ring at the bottom of the shaft with narrow-pointed pliers.
11. Remove the lower bearing.
12. Push out the shaft downwards through the upper body.
13. Remove the top bearing after pulling out the shaft.
4.4 Reassembling the Anemometer
1. Attach the top bearing.
2. Push the shaft upwards through the upper body.
3. Attach the lower bearing.
4. Attach the internal retaining ring at the bottom of the shaft.
5. Attach the spacer ring.
WAA151 User Guide M210293EN-C
14

6. Attach the external retaining ring.
7. Attach the chopper disc onto the shaft. Make sure the disc is positioned so that the disc
teeth do not touch the opto-coupler on the circuit board. Tighten the screw.
Make sure that the chopper disc teeth do not touch the opto-
coupler. There must be 1 ... 2 mm space between the bottom of the opto-
coupler and the disc teeth.
CAUTION!
Be careful when handling the new ball bearings. Do not drop them or force
them onto the shaft.
8. Attach the heating element outlet to the circuit board. Put the circuit board in place and
fasten it with spacers.
9. Put the lower body assembly carefully into place.
Make sure that the bigger O-ring between the upper and lower sensor bodies is in place
and fasten the three screws at the bottom of the sensor.
Vaisala recommends replacing the O-ring with a new one when opening the
assembly for maintenance.
10. Tighten the hexagon nut of the connector.
11. Connect the cable plug to the sensor body connector. Fasten the sensor body on the
cross arm with three screws.
12. Mount the cup assembly onto the sensor body. Tighten the fixing screw.
Replacing the heating resistance element requires special
tools. To avoid any damages, Vaisala recommends that the manufacturer
replaces the heating element.
CAUTION!
Chapter 4 – Maintenance
15

5. Troubleshooting
Table 3 Troubleshooting the Anemometer
Problem Probable Cause Remedy
The data is not received from
the sensor.
The sensor is mechanically
damaged.
Check the cables and
connectors.
After removing the connector's
hexagon nut, the connector is
bent, which breaks the
connection wires.
Check the connector.
The sensor is not powered
properly.
Make sure that the supply
voltage is 9.5 ... 15.5 VDC.
Some Vaisala products such as
WAT12 switch power on to the
sensor only for a very short
period (200 s to 500 s).
Make sure that the sensor
output rises above Uin - 1.5 V at
the end of the power pulse.
The sensor shaft is covered
with ice and snow.
The heating element does not
function.
Send the sensor to Vaisala for
repair. Contact Vaisala
Technical Support.
The heating element is not
properly connected.
Open the sensor and make sure
that the heating element outlet
is connected to the connector
on the printed circuit board.
See Replacing Consumables
(page 12).
The output from connector pin
C tracked with an oscilloscope
is not square wave.
The printed circuit board is
damaged.
Replace the printed circuit
board. See Replacing
Consumables (page 12) and
Spare Parts and Accessories
(page 19) for spare part order
code.
The frequency is not equal to 14
times revolution rate.
Current consumption is more
than 28 mA when the shaft is
rotated mechanically.
WAA151 User Guide M210293EN-C
16

6. Technical Data
6.1 WAA151 Specifications
Table 4 Measurement Performance
Property Description/Value
Sensor/Transducer type Cup anemometer/opto-chopper
Observation range 0.4 … 75 m/s (0.9 … 168 mph)
Starting threshold 1) < 0.5 m/s (1.1 mph)
Distance constant 2.0 m (6 ft 7 in)
Transducer Output
0 … 75 m/s (0 … 168 mph) 0 … 750 Hz square wave
Characteristic transfer function Uf (wind speed) = 0.328 + 0.101 × R (output
pulse rate)
Transducer Output Level
(Iout < +5 mA) High state > Uin –1.5 V
(Iout > -5 mA) Low state < 2.0 V
Accuracy Within 0.4 … 60 m/s (0.9 … 134 mph)
With characteristic transfer function (standard
deviation)
±0.17 m/s (0.38 mph)
With simple transfer function Uf= 0.1 × R ±0.5 m/s (1.12 mph)
1) Measured with the cup wheel in position least favored by flow direction. The optimum
position yields a < 0.35 m/s (0.8 mph) starting threshold.
Table 5 Inputs and Outputs
Property Description/Value
Electrical connections MIL-C-26482 type, 6-wire cable
Cabling 6-wire cable through cross arm
Recommended connector at cable end SOURIAU UTS6JC10E6P
Operating power supply Uin = 9.5 … 15.5 VDC, 20 mA typical
Chapter 6 – Technical Data
17

Property Description/Value
Heating power supply AC or DC 20 V, 500 mA nominal
Settling time after power-up < 30 µs
Table 6 Operating Environment
Property Description/Value
Operating temperature 1) −50 … +55 °C (−58 … +131 °F)
Storage temperature −60 … +70 °C (−76 … +158 °F)
Operating humidity 0 … 100 %RH
1) With shaft heating.
Table 7 Mechanical Specifications
Property Description/Value
IP rating IP65
Dimensions (H × Ø) 240 × 90 mm (9.45 × 3.54 in)
Swept radius of cup wheel 91 mm (3.58 in)
Weight 570 g (1.26 lb)
Materials
Housing AlMgSi, gray anodized
Cup PA, reinforced with carbon fiber
Table 8 Compliance
Property Description
Wind tunnel tests ASTM standard method D5366-96 (for starting
threshold, damping ratio, overshoot ratio, and
delay distance)
Exploratory vibration test MIL-STD-167-1
Humidity test MIL-STD-810E, Method 507.3
Salt fog test MIL-STD-810E, Method 509.3
EMC compliance EN/IEC 61326-1:1997 + Am1:1998, Am2:2001,
Generic Environment
WAA151 User Guide M210293EN-C
18