Vaisala WAT12, Руководство пользователя

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3.4.4 Optional heating power
WAT12 also provides the sensors with a throughput for optional heating power. The heating
power connection requires an extra pair of wires. Since the heating elements in the shafts of
WAA151 and WAV151 typically consume some 500 mA, the heating power is most conveniently
supplied from a local power source. A thermostat switch is available for automatic connection
of the heating power in temperatures below +4 °C (39.2 °F).
The optional heating power requirement is 20 V AC or V DC, and 500 mA for both WAV151 and
WAA151. The sensors can be connected in series, when a 40 V power supply providing 500 mA
is required. Alternatively, the sensors can be connected in parallel, when a 20 V power supply
providing 1 A is required
Figure 13 Default heating power connection with both sensors
3.4.5 Wiring examples
• Basic wiring with WAA151 and WAV sensors
• Wiring with WHP151 mains power supply
• Wiring with WHP25 mains power supply and WA25 sensors
Chapter 3 – Installation
19