Installation Instructions; Atex / Iecex; Ip Protection Rating Of Housing; Electrical Connections - ABB TTH300 Series Operating Instruction

8 TTH300 HEAD-MOUNT TEMPERATURE TRANSMITTER | OI/TTH300-EN REV. E
... 2 Use in potentially explosive atmospheres in accordance with
ATEX and IECEx

Installation instructions

ATEX / IECEx

The installation, commissioning, maintenance and repair of
devices in potentially explosive atmospheres must only be
carried out by appropriately trained personnel. Works may be
carried out only by persons, whose training has included
instructions on different types of protection and installation
techniques, concerned rules and regulations as well as general
principles of zoning. The person must possess the appropriate
competences for the type of work to be conducted.
When operating with combustible dusts, comply with
EN 60079-31.
The safety instructions for electrical apparatus in potentially
explosive areas must be in accordance with Directive
2014/34/EU (ATEX) and IEC 60079-14 (Installation of electrical
equipment in potentially explosive areas).
Comply with the applicable regulations for the protection of
employees to ensure safe operation.

IP protection rating of housing

The temperature transmitter and LCD indicator Type A and
Type AS must be installed such that an IP rating of at least IP 20
is achieved in accordance with IEC 60529.

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 1: 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