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Installation:
Transmission Range
:
The distance that the 4-20 mA signal can travel
is
dependent on several factors including the cable gauge. Maximum
cable resistance allowed is 600 ohm less the controller resistance.
Assume a constant 24 VDC power supply (at 20 Deg C), copper wire and
a controller resistance of 250 ohm. The signal range from the
controller to the transmitter takes into account the return loop.
Note: The Uniphos-500 Series Controllers have a resistance of 100
ohm maximum.
Maximum cable lengths between the controller & transmitter:
The table give below is for guidance only. Users should calculate
maximum distances using actual data for the cable being used.
Typical calculations assume minimum guaranteed controller supply of
24 VDC, minimum detector voltage of 18 VDC & maximum power supply
under full alarm.
Table: 01
Typical cable data
Maximum cable length
Cable size
(Cross section)
Cable
Resistance
Catalytic
EC
IR
Ω/km
meters
meters
meters
0.5 mm2 (20AWG)
36.8
356
478
420
1.0 mm
2
(17AWG)
19.5
671
902
793
1.5 mm
2
(16AWG)
12.7
1031
1384
1217
2.0 mm
2
(14AWG)
10.1
1296
1741
1531
2.5 mm
2
(13AWG)
8
1636
2197
1932
