Electrical Connections - ABB TTF200 Operating Instruction

10 TTF200 FIELD-MOUNT TEMPERATURE TRANSMITTER | OI/TTF200-EN REV. A
2.4.3

Electrical connections

Grounding
If, for functional reasons, the intrinsically safe circuit needs
to be grounded by means of a connection to the potential
equalization, it may only be grounded at one point.
Intrinsic safety proof
If transmitters are operated in an intrinsically safe circuit,
proof that the interconnection is intrinsically safe must be
provided in accordance with IEC/EN 60079-14 as well as
IEC/EN 60079-25.
The supply isolators / DCS inputs must feature intrinsically
safe input protection circuits in order to eliminate hazards
(spark formation).
In order to provide proof of intrinsic safety, the electrical
limit value must be used as the basis for the EC-type
examination certificates for the equipment (devices); this
includes the capacitance and inductance values of the
cables.
Proof of intrinsic safety is said to have been provided if the
following conditions are fulfilled when a comparison is
carried out in relation to the limit values of the equipment:
Transmitter
(intrinsically safe equipment)
U
i
I
i
P
i
L + L (cable)
i c
C + C (cable)
i c
Field (Ex area)
+
-
A
Fig. 3
A Transmitter B Supply isolator / DCS input with supply /
segment coupler
Supply isolator / DCS input
(related equipment)
≥ U
o
≥ I
o
≥ P
o
≤ L
o
≤ C
o
Control room (safe area)
+
-
B
Installation in a potentially explosive atmosphere
Transmitters can be installed in all kinds of industrial
sectors. Potentially explosive systems are divided into
zones,
meaning that a wide range of different instruments are also
required. For this, pay attention to the country-specific
guidelines and certificates!
NOTICE
Ex relevant specifications must be taken from the
respective valid declaration of conformity and the type
examination certificate.
ATEX - Zone 0
Marking: II 1 G Ex ia IIC T6 Ga
Ex area Zone 0
ia
J
A
Fig. 4
A Sensor B Transmitter TTF200 C Supply isolator [Ex ia]
D Interface for LCD display
The input for the supply isolator must have an "Ex ia"
design. When using the transmitter in Zone 0, make sure
that impermissible electrostatic charging of the transmitter
is avoided (observe the warnings on the device).
As the user, it is your responsibility to ensure that the
sensor instrumentation meets the requirements of
applicable explosion protection standards.
WARNING
A10096
Risk of explosion!
When using the device in areas that require the device
safety level EPL "Ga" (Zone 0), the TTF200 types must be
installed with aluminum housings, protected against
strong mechanical impacts or friction.
Safe area
D
ia
ia
B C
A11227