Installation And Wiring; Installation Preparations - Vaisala HMT370EX Serie Installations- Und Sicherheitshinweise

4 Installation and wiring
WARNING!
ensure that an IEC 60079-14 compliant safe work procedure has been
implemented in the hazardous area.
WARNING!
be opened in a hazardous area. The probe can be detached and changed
when HMT370EX is powered. Any other live maintenance, including changing
the probe head filter, is not allowed.
4.1 Installation preparations
Before starting the installation, check the following:
• Make sure that your installation site suits the Ex classification of the transmitter: see
1 (page 6).
• Review the hazardous area information in
(page 7) for further information on Ex safety requirements related to HMT370EX and
specific conditions of use.
• Review the wiring diagrams included in this document for information on wiring using
either a galvanic isolator or a Zener barrier.
• Wiring with galvanic isolators (page 17)
• Wiring with Zener barriers (page 18)
• When selecting the cable glands and plugs for your application, make sure they are Ex
compliant. The glands and plugs must be water and dust tight.
Wiring information
WARNING!
mandatory in a hazardous environment.
CAUTION!
(CH1) must always be wired. The transmitter receives power through the
Channel 1 screw terminals, and does not power on if only Channel 2 (CH2) is
wired.
12
The installation must be carried out in a safe area, or you must
When HMT370EX is powered, the transmitter enclosure must not
Protected installation using galvanic isolators or Zener barriers is
When planning the wiring of your application, note that Channel 1
Guidelines for safe use in hazardous conditions
M212306EN-A
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