KROHNE OPTITEMP TT 60 C-R EN - Manual (Page 14)

11/2010 – 4000754401 – MA OPTITEMP TT60CR R01 en www.krohne.com 14
CAUTION! CAUTION! CAUTION! CAUTION!
EN 61158-2 stipulates that all data bus interfaces must be isolated from the local ground.
The ProfiBus must not be grounded.
Figure 5: Circuit schematic, ProfiBus shielding and grounding
1 Power supply
2 Supply cable
3 Connection box
4 Connection cable to field device
5 Field device
6 Equipotential bonding
4.3.2 Cable parameters for areas with potentially explosive atmospheres
Resistance Values
Cable resistance 15...150 Ω/km
Cable inductance 0.4...1 mH/km
Cable capacitance 45...200 nF/km