WIKA TC12-M - Handbuch (Seite 28)

GB
8. Safety-related instructions for the different variants
14083458.01 09/2013 GB/D
WIKA operating instructions models TR12, TC12 (Ex i) 28
8. Safety-related instructions for the different variants
8.1 Variant 1:
ATEX/IECEx Ex d housings or connection heads (with connection terminals, without
transmitter). Evaluation of the resistance or the thermoelectric potential between electronics
outside of the hazardous area.
Use in zone 1, marking II 2G Ex ia IIC T1-T6 Gb
The housing or the connection head is in zone 1 (or zone 2). The sensor is located in
zone 1.
Use with a thermowell at the partition to zone 0, marking II 1/2G Ex ia IIC T1-T6 Ga/Gb
The housing or the connection head is in zone 1 (or zone 2). The sensor is within a
thermowell (min. wall thickness 1 mm) which extends into zone 0 via a process connection.
The thermometer should therefore be operated with a power-limiting circuit.
Powering with Ex ia electrical circuit fulfills these conditions. The responsibility rests with the
operator.
Temperature class classification, ambient temperatures
For all WIKA connection heads, the following ambient temperature range applies:
(-50) 1) -40 … +80 °C
1) The value in brackets applies only for specific low-temperature designs.
The permissible ambient temperatures for third-party products can be seen from the
relevant approvals and/or data sheets.
A heating in the connection head does not occur with varient 1. However, an impermissible
heat reflux from the process which can exceed the operating temperature of the housing or
the temperature class, must be prevented through suitable heat insulation or a suitably long
neck tube.
8.2 Variant 2:
ATEX/IECEX Ex ia housing or connection head with built-in head-mounted transmitter.
The evaluation is made via a current (4 … 20 mA), voltage (2 … 10 V) or field bus signal,
which is generated from a head-mounted transmitter.
Use in zone 1, marking II 2G Ex ia IIC T1-T6 Gb
The housing or the connection head is in zone 1 (or zone 2). The sensor is located in
zone 1.
Use with a thermowell at the partition to zone 0, marking II 1/2G Ex ia IIC T1-T6 Ga/Gb
The housing or the connection head is in zone 1 (or zone 2). The sensor is within a
thermowell (min. wall thickness 1 mm) which extends into zone 0 via a process connection.