Endress+Hauser PROline promass 83 II2G Manual page 61

PROline Promass 83 FOUNDATION Fieldbus
Endress+Hauser
Intrinsically safe equipment
Promass 83
Total capacitance
C = 115.6 nF
eff.
Total inductance
= 423.1 P H
L
eff.
Tab. 12: Safety considerations (example)
If, in the example examined, the condition L
intrinsic safety with respect to the electrical parameters has a positive result. In this
example, however, the condition was not met since the bus line selected is too long.
Possible solutions:
1. Reduce the main line by 175 m to 405 m (this can be achieved by installing the barrier in the
immediate vicinity of Explosion Zone 1, for example).
2. Check under what conditions the manufacturer of the safety barrier or segment con-
nector allows the use of the L/R ratio for technical safety considerations.
Since all the users are permissible for explosion group IIC and the corresponding
parameters have been taken into consideration, the bus segment can be used for gases
in explosion group IIC.
The permissible ambient temperature may be considered either individually for each
device at the respective place of installation, or specified uniformly for the bus segment
as a whole. In the latter case the lowest value of the ambient temperature applies.
Required temperature class
T6
Condition Associated equipment
MTL 5053
< perm. capacitance for IIC
C = 165 nF
o
< perm. inductance for IIC
= 320 P H
L
o
< L is met, then the demonstration of
eff. o
Intrinsically safe equipment
Cerabar S
Promass 83
0
<
Condition met?
 Yes
No
Maximum ambient temperature
40 °C
50 °C
(at 80 °C medium temperature)
25