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MULTICAL®
602
76
Kamstrup
A/S
∙
Technical
Description
∙
5512
‐
931_N1_GB_11.2016
8.2
Cable influence and compensation
8.2.1
2 wire sensor set
Small and medium-sized heat meters only need a relatively short temperature sensor length, and the 2 wire sensor
set can be used with the advantage of easy installation.
The cable length and the cross sectional area must always be identical for the 2 sensors used as a temperature
sensor pair for a heat meter. The length of the cable sensors must neither be shortened nor extended.
The limitations attached to using the 2 wire sensor set according to EN 1434-2:2007 are stated in below table.
Kamstrup supply Pt500 sensor sets with up to 10 m cable (2 x 0.25 mm
2
)
Cable cross
section
mm
2
Pt100 sensors
Pt500 sensors
Max. cable length
m
according to
EN 1434-2:2007
Temperature
increase
K/m
Copper @ 20
C
Max. cable length
m
according to
EN 1434-2:2007
Temperature
increase
K/m
Copper @ 20
C
0.25
2.5
0.450
12.5
0.090
0.50
5.0
0.200
25.0
0.040
0.75
7.5
0.133
37.5
0.027
1.50
15.0
0.067
75.0
0.013
Table 6
8.2.2
4 wire sensor set
For installations requiring longer cable lengths than stated in above table, we recommend a 4 wire sensor set and
a MULTICAL
®
602 type 602-B with 4 wire connection.
The 4 wire construction uses two conductors for testing current and the two other conductors for measuring signal.
In this way, the construction will in theory not be affected by long sensor cables. However, in practice cables longer
than 100 m should not be used. We recommend to use 4 x 0.25 mm
2
.
The connection cable should have an outside diameter of 5-6 mm to obtain optimal tightening in both