Prosense PQ Series Installation And User Manual page 16

Minimum power consumption of the detector without any optional module is 1W. The
current required to drive the detector at the minimum voltage is
(I = P / V) : 1.0 / 12 = 85mA (I detector).
Maximum power consumption of the detector when optional relay modules installed and all
relays are active is 4.0W. The current required to drive the detector at the minimum voltage
is (I = P / V) : 4.0 / 12 = 335 mA (I detector).
So, the maximum field cable loop resistance (R loop) = 12 / 0.335 = 36 Ohms, or 18 Ohms per
core, (allowing for component variations, losses, etc.).
The following tables show the maximum cable distances between the controller and
transmitter assuming a voltage drop of 6V in each core and for different cable parameters.
The tables are examples only and actual cable parameters and source power supply voltage
for the application should be used to calculate the maximum cable distance allowed at the
installation site.
Typical cable data for detector with relay module given in Table-4:
Cable size
(cross sectional area)
0.5mm2
1.0mm2
1.5mm2
2.0mm2
2.5mm2
PRS-UM-PQ-EN-Rev.05-18.06.2020
Cable type
nearest equivalent
20AWG
17AWG
16AWG
14AWG
13AWG
Table 4: Typical cable details and maximum distance for cabling
Cable resistance
Maximum Cable length (L)
Ω/km
36.8 Ω/km
19.5 Ω/km
12.7 Ω/km
10.1 Ω/km
8.0 Ω/km
Meters
~400
~700
~1100
~1400
~1800
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