Mounting Examples - WIKA TR12 Zusatzinformation

3. Commissioning, operation

3.6 Mounting examples

3.6.1 Possible installation methods with the marking II 1G Ex ia IIC T6 Ga or
II 1D Ex ia IIIC T65 °C Da
Zones 0, 1, 2 or zones 20, 21, 22
Thermowell
TWxx
The probe together with case or connection head is located in zone 0 (zone 20). An Ex ia
type current circuit must be used. Connection heads/cases made of aluminium are usually
not permitted in zone 0. At this position, WIKA recommends connection heads/cases made
of stainless steel.
Protective measures for applications that require EPL Ga or Da:
For the case where a light metal case is used in zone 0, the following protective measures
apply:
Operationally based friction or impacts between light metal instrument components or their
alloys (e.g. aluminium, magnesium, titanium or zirconium) and instrument components
from iron/steel, are not permitted. Operationally based friction or impacts between light
metals are permitted.
Observe the special conditions (see chapter 4 "Special conditions for use (X conditions)",
points 5 and 7).
WIKA additional information TR12/TC12, intrinsically safe designs (Ex i)
Hazardous area
Process
connection
Connection head/
Field case
Compression
fitting
Non-hazardous area
Tx12-B
Tx12-A
Option:
with built-in
transmitter
e.g. T32
Tx12-B
Tx12-A
Associated
electr. equipment
Intrinsically
safe supply or
suitable barrier
Intrinsically
safe supply or
suitable barrier
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EN