I bought at Castorama 50 meters cheaper cable UTP CAT5E, measured the resistance of its living, calculated voltage drop and tested in practice.
LAN cable with copper conductors are now quite expensive - from 4400 rubles for a bay 305 meters (14.42 rubles per square meter).
To reduce the cost of manufactured cables with conductors omednonnymi CCAW (Copper Clad Aluminium Wires).
This cable is worth 2200 rubles per bay 305 meters (7.21 rubles per square meter).
Note that I'm talking about a cable with eight wires 24AWG with 0.51 mm core diameter (reason for UTP cables are not always specified cross section, both in electrical engineering, and the diameter). To further reduce the cost of producing the wires with the wires 26AWG (0.4 mm) and two pairs (four wires).
In cable CCAW several drawbacks:
- brittle veins;
- deterioration of contacts in connectors with time;
- greater resistance.
However, for the construction of its cheap systems used.
SuperNet CAT5E 4x2x0.5 cable sold and Castorama (11 rubles per square meter) and Leroy Merlin (12 rubles per square meter).
On the cable itself is not specified anything except "CAT5E UTP" and label length.
Conductor diameter 0.5 mm really.
The resistance of a 50-meter core 7.1 ohms. He had to measure multimeter as Milliommetr has a measuring range of 2 ohms.
However, with the help of Milliommetr you can measure the resistance of all conductors, connected in parallel. This resistance was 0.888 ohm, respectively one core - 7.104 Ohm - meter was right.
Resistance 50 meters of copper wire diameter of the de amounted to 4.359 ohms, respectively, in the wire CCAW resistance is greater than 63%.
To check the tension on the wire decreases in real terms, I connected through the camera Azishn on SONY IMX323 Consumed from the 104 volt 12 mA in the normal mode and 397 mA in the night mode IR (ammo1.livejournal.com/1046347.html). To supply used 4 core cable, two vparallel. Accordingly, the overall resistance of the supply conductors was 7.1 ohms.
The voltage on the power supply - 12.26 V.
The voltage at the cell normally 11.51 B.
Tension on the camera in night mode, the backlight is - 9.99 V.
The camera operates at the same voltage (as I wrote, all cameras are not scary and the voltage drop to 7.5 volts), the backlight burns less brightly than at 12 V.
Typically the length of cable to the camera does not exceed 15 meters, so despite the high resistance conductors, the voltage drop even in the night mode would be less than 1 V. Given that most of the power supply voltage for the cameras offer "with a stock" (as many BBP and general 13.5), voltage drop across the cables is no fear and safely connect the unit via the local cable network.
Through segments of this cable is already connected to a surveillance camera on my mother's cottage. So far, everything works fine, we'll see how the cable CCAW survive the winter.
© 2019 Alex Nadozhin