Mounting Examples - WIKA TR12 Serie Manual De Instrucciones

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
15
EN