Kamstrup MULTICAL 402 - Cable Influence; Installation

MULTICAL® 402
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Kamstrup A/S · Technical Description · 5512-742_M1_GB_01.2016
9.2 Cable influence
9.2.1 2-wire sensor set
Usually small and medium-size heat meters just need temperature sensors with relatively short cable lengths.
Thus, 2-wire sensor sets can be used with advantage.
Cable lengths and cross sections of the two sensors which are used as temperature sensor set for a heat meter
must always be identical, and must neither be shortened nor extended.
The limitations connected to the use of 2-wire sensor sets according to prEN 1434-2:2009 appear from the table
below.
Cable cross
section
[
mm
2
]
Pt100 sensors Pt500 sensors
Max. cable length
[m]
Temperature
increase [K/m]
Copper @ 20
° C
Max. cable length
[m]
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
Table 10
Kamstrup supply Pt500 sensor sets with up to 10 m cable (2 x 0.25 mm
2
)
9.3 Installation
9.3.1 Electrical connection
The two paired 2-wire sensors must be mounted in terminals 5 and 6 (T1), and 7 and 8 (T2). The polarity of
temperature sensors T1 and T2 is unimportant.
See the position of the terminals below:
Terminal no.
Standard heat and cooling
measurement
T1
5-6 Sensor in forward pipe (red)
T2
7-8 Sensor in return pipe (blue)