Dräger Polytron 8000 Series

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