Vaisala WAA151 - Manual (Page 9)

Chapter 2 ____________________________________________ Product Overview
VAISALA___________________________________________________________7
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces WAC151 Cross Arm features.
Introduction to WAC151 Cross Arm
The WAC151 Cross Arm assembly supports the installation
of the Vaisala WAA151 Anemometer and WAV151 Wind
Vane, or WAA252 Heated Anemometer and WAV252
Heated Wind Vane. The cross arm assembly consists of a
junction box and an anodized aluminum tube construction
with a mounting clamp for installation on the top of a pole
mast.
A water tight junction box includes a screw terminal block
for connection of the power and signal cables. Inside the
junction box, there is also a thermostat switch for
controlling sensor shaft heating for the 151 series sensors.
The thermostat switch connects the heating power in
temperatures below +4 °C. The 252 series sensors do not
use the cross arm's thermostat switch, as they have the
temperature control integrated in the sensor's electronics.
The junction box is equipped with four cable glands offering
easy connection to different cables. Typically, three cable
glands are in use; two for sensor cables and one for signal
cable. The fourth gland is reserved, for example, for the
cable supplying heating power to heated sensors.