3. Explosion Protection Instrumentation in Zone 2/Division 2
3-10
TI 33Q01J30-01E
Example
We discuss the case where AAI141 of CENTUM I/O module, a power input module and EJA, a
differential pressure transmitter of Yokogawa Electric Corporation are connected.
EJA is connected to the circuit of AAI141 via a 100m cable, and installed in a hazardous area of
Class I, Division 2.
Power
Supply
Lc
Cc
Li
Ci
Device that gives energy
(The source device)
Device that receives energy
(The load device)
F030103.ai
Hazardous area (Class I, Division 2)
<CS 3000 AAI141>
<Differential pressure transmitter EJA>
The defined parameters have the following values.
(Voc) = 27.6 V
(Isc) = 27 mA
(Ca) = 0.19 mF
(La) = 2.7 mH
(Cn) = 0.19 mF at
(Vn) = 27.6 V
(Ln) = 100 mH at
(In) = 24.0 mA
and,
(Cc) = 200 pF/m X 100 m = 0.0002 mF X 100 = 0.02 mF
(Lc) = 0.66 mH/m X 100 m = 0.00066 mH X 100 = 0.066 mH
therefore,
Voc = 27.6 V
<
Vmax = 30 V
Isc = 27.0 mA
<
Imax = 165 mA
Ca = 0.19 mF
>
Ci + Cc = 0.0425 mF
La = 2.7 mH
>
Li + Lc =0.796 mH
The results above meet the combinational conditions. It can be judged that a field wiring can be installed
in accordance with a general wiring construction.
(Vmax) = 30 V
(Imax) = 165 mA
(Ci) = 0.0225 mF
(Li) = 0.73 mH
+
-
+
-
Figure Connection of AAI141 and EJA
May 18, 2018-00
