English; Wire Connection - Vaisala HMT360 Manual Del Usuario

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HMT360 Installation in Hazardous Locations
WARNING!
In hazardous environments, always connect the transmitters via galvanic isolators or Zener
barriers. A galvanic isolator or Zener barrier must also be used when the transmitter body is in
a safe area, but the probe is installed in a hazardous environment. Examples of protected
installations are provided on the next page. Also read the HMT360 User's Guide before starting
the installation.
The transmitter does not include a galvanic isolator or a Zener barrier. They can be ordered as
optional accessories from Vaisala.

2-wire Connection

Connect the unpowered power supply wires to the connectors: Ch 1 (humidity) and Ch 2
(temperature). Both channels require an own power supply. As Ch 1 is a main output, the
transmitter does not operate if only Ch 2 is connected (Ch 2 is optoisolated from transmitter
electronics).
Special Conditions for Safe Use Under EU ATEX Directive
1. The equipment with display window and/or with associated cable of the sensor head can
be used in Zone 0 Group IIC areas only if the danger of ignition due to electrostatic charge
is avoided.
2. With the installation of the equipment in Zone 0 Group II area it has to be ensured that
sparks due to impact or friction do not occur.
3. The serial interface must only be used outside the explosion hazardous area. The
associated serial interface cable 25905ZZ is to be used.
4. Allowed ambient temperature range is -40 °C ... +60 °C for the transmitter.
5. For the probe types HMP362, HMP364, HMP365, HMP367, and HMP368 the allowed
ambient temperature range is -70 °C ... +120 °C for the temperature class T4 and the
allowed ambient temperature range is -70 °C ... +180 °C for the temperature class T3.
6. For the probe type HMP361 the allowed ambient temperature range is -40 °C ... +60 °C
and the temperature class is T4.
7. For the probe type HMP363 the allowed ambient temperature range is -40 °C ... +120 °C
and the temperature class is T4.
Protected installation is mandatory in a hazardous environment.
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