Sensor Line Resistance - Honeywell 5704 Operating Instructions Manual

MAN0448_Issue 13_01-2010
005704-M-5001 A03249
CHAPTER 4 - INSTAllATION INSTRUCTIONS
11.2

Sensor line Resistance

Sensors should be located such that the line resistance of cable does
not exceed the maximum permitted. The table below gives a quick guide
to the maximum cable lengths permitted for specific sensors, when
connected by stranded copper conductor cables of various sizes to a
System 57 running at the minimum dc input voltage.
Device or Sensor Type
704/705
780 (at 200mA bridge current)
811
910 (Single pair at 200mA)
910 (2 pair at 200mA)
911
SensePoint Flam. LEL/ppm
SensePoint Toxic
SignalPoint Flamable
SignalPoint Toxic
Digi-Cat
Digi-Chem
Digi-Ana
Digi-Optima
Life Line
Searchline
(minimum dc supply 21V)
Searchpoint 500
Searchpoint OPTIMA
(minimum dc supply 19V)
Series 2000 Flammable
Series 2000 Toxic
Searchline Excel Receiver
(Minimum dc supply 21V)
Searchline Excel Transmitter
(S/R) (Minimum dc supply 21V)
Searchline Excel Transmitter
(L/R) (Minimum dc supply 21V)
Searchline Excel Cross Duct
Transceiver assembly
(Minimum dc supply 21V)
Searchpoint Optima Plus
Apex - Toxic
Apex - Combustible/Thick Film
Opus/LLII - Toxic
Opus/LLII - Combustible
The figures in the table above provide a useful reference guide to
maximum cable lengths, however, in many circumstances longer cable
runs can be used. eg. Where the dc input voltage is higher than the
minimum. In these circumstances a more detailed analysis is required
to determine maximum line resistance.
WARNING
It is required that verification by testing that cable faults (open circuit and
short circuit) at the transmitter's side are correctly detected by the control
card. The control card shall indicate ER81, ER87 or ER88 in this case.
Maximum Cable Length (m)
Conductor Cross Sectional Area
AWG 21 19
mm˝ 0.50 0.75
500 750
500 750
5600 8400
480 720
230 340
5600 8400
500 750
3200 4800
500 750
2000 3000
400 570
1000 1500
1000 1500
180 260
3200 4600
60
32
180 270
450 670
1600 2400
90 135
141 211
94 141
55
159 237
180 270
130 195
300 450
250 375
4-16
5704 Control System
18 16
1.00 1.50
1000 1500
1000 1500
11200 16800
960 1400
460 690
11200 16800
1000 1500
6400 9600
1000 1500
4000 6000
800 1150
2000 3100
2000 3100
360 540
6500 9750
90 120 180
48 64 96
360 540
900 1300
3200 4800
179 271
282 425
188 283
82 109 165
315 476
360 540
260 390
600 900
500 750
14
2.50
2500
2500
28000
2400
1100
28000
2500
16000
2500
10000
1850
4800
4800
860
15000
300
160
900
2200
8000
449
704
998
274
787
900
650
1500
1250