CCTV cable long distance

CCTV installation & trouble shooting in long cable run

When cable run exceeds 300m, it is advised to use active balun for better video signal. In long cable run, it is must to have group loop isolation for better video balance and performance. The below diagram explains basic CCTV installation with long cable run.

The Active balun transmitter provides good performance for CCTV video channel via Cat5 unshielded twisted pair (UTP) cable. The balun is installed at the CCTV camera known as transmitter and is powered by the camera power supply (Please check Amp requirements). This CCTV active transmitter balun should be equipped with ground loop isolation for enhance performance.


Common issues with  cctv cable long distance and trouble shooting

The below paragraph describes some of the common issues in long cable run. It describes some of the symptoms, probable causes and possible solutions.




Poor CCTV picture quality, distortion, interference and etc

  • This could be EMI interference, check that wires are not too close to power transformers or ballasts. This can also happen due to wires connected reversed on signal pair on one side – Make sure they are connected properly.

Continuity is broken –

  • Run a continuity check on cables (UTP) using multi-meter or Ground loop voltage is high and imbalance – Equalize the difference in group loop voltage

 No video image

No power connected –

  • Check power connection and make sure they are connected
  • Check power supplies for correct reading for voltage

Wires are connected in wrong way –

  • Check whether positive and negative wires are connected incorrectly. Red or brown is normally for positive and black or blue is used for negative and green & yellow used for earth.

Defective balun –

  • Check the continuity and resistors inside balun. 

CCTV picture over compensated

Too strong video signal –

  • Adjust the switch to correct distance setting. 

CCTV picture faded, weak or black and white

Too weak video signal –

  • Adjust the switch to correct distance setting.

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