Electrical Connections; Commissioning; Operating Instructions; Protection Against Electrostatic Discharges - ABB TTH200 Operating Instruction

TTH200 HEAD-MOUNT TEMPERATURE TRANSMITTER | OI/TTH200-EN REV. B

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 installation check
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)
L + L (cable) ≤ L
i c
C + C (cable) ≤ C
i c
Field (Ex area)
A Transmitter
Figure 6: Intrinsic safety installation check
Supply isolator / DCS input
(related equipment)
U ≥ U
i o
I ≥ I
i o
P ≥ P
i o
o
o
Control room (safe area)
B Supply isolator / DCS input with
supply / segment coupler
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!
Note
Ex relevant specifications must be taken from the EC-type
examination certificates and other relevant certificates that
apply in each case.

Commissioning

The commissioning and parameterization of the device may also
be carried out in potentially explosive atmospheres using a
handheld terminal that has been approved accordingly under
consideration of an intrinsic safety installation check.
Alternatively, an Ex modem can be connected to the circuit
outside the potentially explosive atmosphere.

Operating instructions

Protection against electrostatic discharges

The plastic parts inside the device can store electrostatic
charges.
Make sure that no electrostatic charges can accumulate when
handling the device.
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