ELECTRICAL CONNECTIONS
4
25
TT 51 SERIES
www.krohne.com
08/2015 - 4000754203 - MA TT 51 R03 en
For multiple connections (Multidrop mode), the following formula shall be used:
L = [(65 x 10
6
) / (R x C)] x (Cn x 5000 + 10000) / C
with
L: cable length [m or ft]
R: load resistance (incl. the resistance of any Zener barrier) + cable resistsance [
Ω
]
C: cable capacitance [pF/m or pF/ft]
Cn: number of transmitters in the loop
Conductors
Resistance [
Ω
/km]
(both conductors in series)
Area [mm
2
]
Diameter [mm]
AWG
2.0
1.6
14
17
1.3
1.3
16
28
1.0
1.15
17
36
0.8
1.0
18
45
0.5
0.8
20
70
0.3
0.6
22
110
0.2
0.5
24
160
Table 4-2: Cable parameters
MA_OPTITEMP_TT_51_en_150828_4000754203_R03.book Page 25 Friday, August 28, 2015 10:54 AM
