The table lists example possible lengths of cables based on minimum operating voltage
and corresponding cable cross-section. The table is based on cable resistances calcu‐
lated to VDE 0295 and a load (R
load
) of 500 Ω.
Table 12: Lengths of cable with min. supply voltage and different cable cross-sections
Minimum
supply volt‐
age in V
Cable resist‐
ance in Ω
Maximum length of cable in m with cable cross-section of:
0.14 mm²
0.25 mm²
0.34 mm²
0.50 mm²
0.75 mm²
17
10
35
60
84
124
187
18
50
176
304
423
623
936
20
150
528
914
1271
1870
2808
22
250
880
1524
2118
3117
4681
24
350
1232
2134
2966
4364
6554
26
450
1584
2743
3813
5610
8426
28
550
1936
3353
4661
6857
10299
30
650
2288
3963
5508
8104
12172
7.4
Load resistances
The set load resistance essentially determines the power loss in the sensor, based on
the supply voltage. To keep the power loss low and to avoid the sensor overheating,
a load resistor appropriate for the supply voltage should be used. The following tables
and diagrams illustrate the relationship between supply voltage and permissible load
resistance for various operating temperatures.
The minimum and maximum load resistances specified below should always be under‐
stood as the total resistance at the output. This total resistance comprises the load
resistance and the resistance of the cable.
7.4.1
Load resistance TMx88A
In the figure (
), the permissible load resistance based on the input voltage
for the operating range up to 80 °C is shown in blue. Within a restricted operating
range up to 65 °C, combinations of input voltage and load resistance from the area
shown in gray are also permitted.
Table 13: Minimum, typical, and maximum load resistances TMx88A
U
dd
[V]
R
L
min. [
Ω
] @ Ta
max
=
65 °C
R
L
min. [
Ω
] @ Ta
max
=
80 °C
R
L
max. [
Ω
]
17
0
230
500
24
130
660
850
28
390
900
1050
35
830
1330
1410
7
CONNECTION
24
O P E R A T I N G I N S T R U C T I O N S | TMS/TMM88, TMS/TMM55
8019053/1EF6/2021-12-13 | SICK
Subject to change without notice
