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ABB i-bus
EIB / KNX
4.3
Planning example:
"PT100 2-conductor
technology – 30...+ 70 °C"
Planning and application
A container located outdoors, for storing liquids with a circulation pump,
needs to be protected against minus temperatures (lower than 0 °C).
The heating for the container should be automatically switched on below
+ 4 °C and switched off above + 15 °C. The temperature below 4 °C should
be recorded for longer than 1 minute. The temperature above 15 °C should
be recorded for longer than 30 seconds. The circulation pump should be
switched on below + 6 °C and switched off above + 17 °C. The temperature
below 6 °C should be recorded for longer than 5 minute. The temperature
above 17 °C should be recorded for longer than 10 minutes. In addition,
a line fault compensation via the cable length should be taken into account.
The distance between Analogue Input and PT100 is 150 metres.
The cross-section of the copper cable is 2.5 mm
able to change the threshold values via the bus.
PT100 2-conductor technology – 30...+ 70 °C:
Signal output:
Measuring range:
Measurement curve:
Connection to channel A.
The standard characteristic curve for PT100 2-conductor techno-
logy – 30...+ 70 °C is stored in Analogue Input. The measuring
range of the stored measurement curve is – 30...+ 70 °C.
130,00
125,00
120,00
115,00
110,00
105,00
100,00
95,00
90,00
85,00
-30,00
-20,00
-10,00
Fig. 32: Measurement curve for the standard PT100 with threshold values. Values are rounded.
2
. The user wishes to be
PT100 2-conductor technology in ohms
– 20...+ 60 °C
Linear
Standard characteristic measurement curve of PT100
0,00
10,00
20,00
30,00
Measuring range in -30...+70°C
40,00
50,00
60,00
70,00
45
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