Siemens Desigo TRA Engineering, Mounting And Installation Manual page 35

Hum injection
Signal type
TXM1.8U AI NTC100K
AI NTC10K
All other
signal types
DXR2...
AI NTC100K
AI NTC10K
AI NTC3K
AI R100K
All other
signal types
Line resistance
compensation
("Sensor calibration")
Measured value error
LG-Ni 1000
Key
Siemens
Building Technologies
Another limiting factor for cable length is hum injection for certain sensitive signal
types:
Normal hum
mA Can be maintained
eff
with cable length
-- --
-- --
0.5 300 m / 1000 ft
-- --
-- --
-- --
-- --
0.13 80 m / 260 ft
*) Connect the shield to system neutral
The measured value functions are already adjusted with a line resistance of 1 ohm
and the graphs below take account of this.
Exception: NTC3K, NTC10K and NTC100K.
The graphs below are for copper cable.
Measured value error due to line resistance
F [K]
0,6 mm Ø
2
1
0
-0,21
100
2 L
57 A
Formula: F =
4.7
A Cable cross-section in mm
F Measured temperature error in K
L Cable length in m
Desigo TRA Engineering, mounting and installation
Wiring of field devices (without bus)
Reduced hum
mA
eff
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
on one end.
200
1
2
Can be maintained with
cable length / shield
30 m / 100 ft (80 m with shield *)
30 m / 100 ft (80 m with shield *)
300 m / 10000 ft
30 m / 100 ft
(80 m / 260 ft with shield *)
30 m / 100 ft
(80 m / 260 ft with shield *)
30 m / 100 ft
(80 m / 260 ft with shield *)
30 m / 100 ft
(80 m / 260 ft with shield *)
80 m / 260 ft
²
1 mm
²
1,5 mm
²
2,5 mm
300
L [m]
CM111043en_09
35 / 84
2016-02-22