WIKA TC12-M Benutzerhandbuch

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8. Safety-related instructions for the different variants

14083458.01 09/2013 GB/D

WIKA operating instructions models TR12, TC12 (Ex i)

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)

-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.