Vaisala WAC151 User manual

M210349EN-C
User Guide
Cross Arm
WAC151

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 2021
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 WAC151 Cross Arm...............................................................................5
2.2 Safety..................................................................................................................5
2.2.1 ESD protection...........................................................................................6
3. Installation..........................................................................................................7
3.1 Selecting location..............................................................................................7
3.2 Installing Cross Arm WAC151........................................................................... 9
3.3 Connecting wind sensors............................................................................... 12
3.3.1 Wiring wind sensors WAA151 and WAV151............................................13
3.3.2 Wiring wind sensors WAA252 and WAV252.........................................13
3.4 Mounting wind set on mast............................................................................14
3.5 Aligning wind set.............................................................................................16
4. Maintenance.....................................................................................................18
4.1 Visual checking................................................................................................ 18
5. Troubleshooting............................................................................................. 19
6. Technical data................................................................................................20
6.1 WAC151 specifications................................................................................... 20
Technical support............................................................................................. 21
Warranty and product returns...................................................................... 21
Recycling............................................................................................................ 21
Table of contents
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WAC151 User Guide M210349EN-C
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1. About this document
1.1 Version information
Table 1 Document versions
Document
code
Date Description
M210349EN-C January 2021 Updated WHP151 and WHP25 information.
M210349EN-B August 2018 Installation instructions updated.
M210349EN-A November 2002 The first version of the WAC151 Cross Arm User's
Guide. Supersedes the Technical Reference.
1.2 Related manuals
Table 2 Related manuals
Document code Name
M210293EN Vaisala Anemometer WAA151 User Guide
M210294EN Vaisala Wind Vane WAV151 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.
WAC151 User Guide M210349EN-C
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2. Product overview
2.1 Vaisala WAC151 Cross Arm
The WAC151 cross arm assembly supports the installation of:
• Vaisala Anemometer WAA151 and Vaisala Wind Vane WAV151
• Vaisala Heated Anemometer WAA252 and Vaisala Heated Wind Vane WAV252
The cross arm assembly consists of a junction box and an anodized aluminum tube with a
mounting clamp for installation on the top of a pole mast.
1Mounting flange for Vaisala anemometer
2Junction box
3Mounting flange for Vaisala wind vane
A watertight junction box includes a screw terminal block for power and signal cables. The
junction box houses a thermostat switch for controlling WAA151 and WAV151 shaft heating. The
thermostat switches on in temperatures below +4 °C (39.2 °F).
WAA252 and WAV252 do not use the cross arm thermostat switch. They have the temperature
control integrated in the sensor electronics.
The junction box has 4 cable glands. Typically, 3 cable glands are in use; 2 for sensor cables
and 1 for the signal cable. The fourth gland is reserved, for example, for the cable supplying
heating power to heated sensors.
2.2 Safety
This product has been tested for safety. 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.
WAC151 User Guide M210349EN-C
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3. Installation
To prevent equipment damage, install an air terminal so that the tip
is as high above the instruments and sensors as possible.
CAUTION!
To prevent corrosion and oxidation, use copper paste or equivalent on screws and
connector threads.
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.
WAC151 User Guide M210349EN-C
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