7.30830.32.00
10
8
Outer sheath
Bootstrap signal cable type BTS
The signal converter automatically controls the individual shields (3) to exactly the same voltage as that applied to the signal wires
(5). Since the voltage difference between signal wires (5) and individual shields (3) is virtually zero, there is no flow of current via
the line capacitance 3+5; thus, line capacitance is apparently zero. Much longer cable lengths are then permitted for fluids with
low electrical conductivity levels.
1
Dummy glider wire
2
Insulation
3
Special foil, 1
st
shield
4
Insulation
5
Stranded wire 0.5 mm
2
(20 AWG)
6
Stranded drain wire, 1
st
shield, 0.5 mm
2
(20 AWG)
7
Special foil, 2
nd
shield
8
Stranded drain wire, 2
nd
shield, 1.5 mm
2
(14 AWG)
9
Insulation
10
Mu-metal foil, 3
rd
shield
11
Stranded drain wire, 3
rd
shield, 0.5 mm
2
(20 AWG)
12
Outer sheath
1.5.4 Field current cable
The cross-section of the field current cable (standard not included) is dependent on the length that is required:
length
Cross-section
0 – 150 m (0 – 500 ft)
2 x 0.75 mm
2
Cu (2 x 18 AWG)
150-300 m (500 – 1000 ft)
2 x 1.5 mm
2
Cu (2 x 14 AWG)
300 – 600 m (1000 – 2000 ft)
4 x 1.5 mm
2
Cu (4 x 14 AWG)
1.5.5
Cable lengths: max. allowed distance between primary head and signal converter
•
Determining the maximum permissible distance between primary head and signal converter
1.
The
length of signal cable
is dependent on the electric conductivity
of the liquid product and of the type of cable used.
For BTS cable (optional) the maximum length is 600 m, independent of the conductivity.
For DS cable (standard) the maximum length is as followes:
electr. conductivity
γ
[
µ
S/cm]
max. length
[m]
50
120
100
200
200
400
400
600
2.
The
length of field current cable
is determined by the cable cross-section A
F
, see sect. 1.5.4.
3.
The length of the data interface cable
must not exceed 600 m.
4.
The shortest cable length obtained either according to Point 1, 2 or 3 is the
maximum permissible distance
between
primary head and signal converter!
1.5.6 Connection diagram IFC 110 PF with IFS 4000 PF
In the following diagram you can see how to connect the two devices with each other. In this diagram the
data interface cable
is called “
Q
”, the
field current cable
is “
C
” and the
electrode cable
is “
DS
”.
1
2
3
4
5
6
7
8
9
10
11
12
