22
Technical Manual
|
Dräger Polytron
®
8000 Series
Installation
5.2.1 Cable
lengths
Polytron
®
8200 CAT
5.2.1.1
Cable lengths of the 4 to 20 mA signal connection
The maximum cable length between instrument and control unit depends on
different factors. The following factors are key factors to determine the cable length
for a certain application.
– The specifications of the sensor used
– The cable cross-section
– The ambient temperature
– The type of cable
– The operating voltage
The given cable lengths include a 10% safety margin and are valid for 20 °C (68 °F)
and 50 °C (122 °F). Further values are available upon request.
Type of cable
The cable lengths are calculated for 2 standardized cables of different quality.
– Tinned copper wire, class 5/6 according to IEC 60228 / VDE 0295
Characteristic cable resistance: 41 Ohms/km at 20 °C (134514 Ohms/feet at
68 °F)
– Bare copper wire, class 2 according to IEC 60228 / VDE 0295
Characteristic cable resistance: 36 Ohms/km at 20 °C (118110 Ohms/feet at
68 °F).
5.2.1.2
Cable lengths for 4 to 20 mA signal connection of Polytron
®
8200 CAT DQ
Tinned copper wire, class 5/6 according to IEC 60228 / VDE 0295
Values include a safety margin of 10%.
Operating voltage: 24 V
Bare copper wire, class 2 according to IEC 60228 / VDE 0295
Values include a safety margin of 10%.
Operating voltage: 24 V
AWG
21
20
18
16
13
mm
2
0.5
0.75
1
1.5
2.5
122°F
50°C
feet
925
1391
1857
2710
4521
m
282
424
566
826
1378
68°F
20°C
feet
1033
1555
2077
3028
5056
m
315
474
633
923
1541
AWG
21
20
18
16
13
mm
2
0.5
0.75
1
1.5
2.5
122°F
50°C
feet
1030
1516
2050
3068
5010
m
314
462
625
935
1527
68°F
20°C
feet
1683
1693
2293
3429
5600
m
513
516
699
1045
1707
Содержание Polytron 8000 Series
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