Electrical Interconnection In Explosion Hazardous Areas; Installation In Explosion Hazardous Areas - ABB TTH200 Commissioning Instruction

Electrical connection
4.6

Electrical interconnection in explosion hazardous areas

Depending on the safety requirements, special interconnections are required for use in
explosion hazardous areas.
Important
Observe the "Ex relevant specifications" chapter (see data sheet or operating instructions).
Intrinsic safety
The supply isolators/PLC inputs must feature intrinsically safe input protection circuits in order to
eliminate hazards (spark formation). The interconnection must be inspected. In order to provide
proof of intrinsic safety, the electrical limit values must be used as the basis for the EC type-
examination test certificates of 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:
Fig. 10
A Transmitter
4.6.1

Installation in explosion hazardous areas

Transmitters can be installed in all kinds of industrial sectors. Explosion hazardous areas are
divided into zones, meaning that a wide range of different instruments are also required. The Ex
relevant specifications are stipulated in the section titled " Ex relevant specifications ".
16 - EN
Transmitter
(intrinsically safe equipment)
U
i
I
i
P
i
L + L (cable)
i c
C + C (cable)
i c
Field (explosion hazardous area)
A
≥
≥
≥
≤
≤
+
-
B Supply isolator/PLC input with supply
TTH200
Supply isolator/PLC input
(related equipment)
U
o
I
o
P
o
L
o
C
o
Control room (secure area)
+
-
B
CI/TTH200-EN
A00096