Endress+Hauser PROline promag 53 - Page 59

Proline Promag 53 FOUNDATION Fieldbus
Endress+Hauser 23
0
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Checking the conditions:
Final consideration:
From a purely functional point of view the bus segment shown in the example can be
operated based on the positive results. Further optimization of the network with a view
to connecting a greater number of field devices or realizing a longer line length can be
achieved by selecting the right fieldbus power supply and cable type.
Technical safety considerations
using variant Promag 53***-***********G
Step 1 – compilation of technical values relevant to safety:
Bus power supply MTL 5053 (associated electrical apparatus)
• Nominal values:
U
o
=22 V
I
o
=216 mA
P
o
= 1.2 W
Promag 53 (explosion protected electrical apparatus with intrinsically safe FF output):
• Nominal values:
U
i
=30 V
I
i
=500 mA
P
i
= 5.5 W
L
i
=10 µH
C
i
=5 nF
Cerabar S (explosion protected electrical apparatus with intrinsically safe FF output):
• Nominal values Entity:
U
i
=24 V
I
i
=250 mA
P
i
= 1.2 W
L
i
=10 µH
C
i
=5 nF
Consideration Condition met?
I
seff
≥ I
SEG
71.2 mA ≥ 54 mA
✓ Yes
U
FG eff.
≥ 9 V
11.2 V ≥ 9 V
✓ Yes
Explosion group
IIC IIB IIA
Capacitance C
o
0.165 µF1.14 µF 4.20 µF
Inductance L
o
0.32 mH 3.00 mH 7.00 mH
L/R
ratio
31 µH/Ω 126 µH/Ω 242 µH/Ω
Tab. 5: External connection values of bus power supply MTL 5053 depending on temperature class