14
TTF300
FIELD-MOUNT TEMPERATURE TRANSMITTER | CI/TTF300-EN REV. H
… 2 Use in potentially explosive atmospheres in accordance with ATEX and IECEx
… Installation instructions
In addition, the following points must be observed for TTF300
HART (TTF300-E5H) from HW rev. 02.00.00:
The power supply circuit of the transmitter must be limited by
an upstream fuse with a fuse current rating of 32 mA and a fuse
rated voltage of ≥
30 V. The fuse can be located in the associated
supply isolator or must be separately installed upstream. The
breaking capacity of the fuse must be the same or greater than
the maximum assumed short-circuit current at the installation
site (usually 1,500 A).
The display / service interface must not be used in type of
protection ‘nA’ and ‘ec’.
Note
Use in explosive hybrid mixtures, where explosive dusts and
gases are present simultaneously, is not currently permitted in
accordance with EN 60079-0 and EN 60079-31.
Dust explosion protection – Zone 21
Marking:
II 2D Ex tb IIIC T135°C Db
II 3D Ex tc IIIC T135°C Dc
Ex area Zone 21
Safe area
A
Sensor
B
TTF300 transmitter
C
Supply isolator with voltage limit
(30 V)
D
Fuse, 32 mA
E
Interface for LCD indicator
Figure 8: Hookup in Zone 21 (dust explosion protection)
The power supply circuit of the transmitter must be limited by
an upstream fuse with a fuse current rating of 32 mA. This is not
required if the power supply unit is designed as intrinsically safe
with a ‘Ex ia / Ex ib’ type of protection.
Maximum input terminal voltage of the transmitter: 30 V DC.
The maximum permissible power dissipation in the measuring
inset (sensor) is P
i
= 0.5 W.
As the user, it is your responsibility to ensure that the sensor
instrumentation meets the requirements of applicable explosion
protection standards.
