Tech Tips: Intercoms… Doing It Right By Design

14 Oct, 2020, 4:13 PM

In general, domestic intercom installs are very easy; provided some basic rules are followed.


Before you start cabling you must know what you are going to install. This is because different systems use a different cable and are often not interchangeable. Also, different cabling styles are often used eg ‘daisy chain’ or ‘home run’.


The standard questions to ask are:-

  1. Audio/Video or both?
  2. How many door stations/entries?
  3. Are they to be flush or surface mounted?
  4. Are there any lock releases?
  5. How many internal stations?


From this, the exact equipment list may be determined and the correct cable installed.


Many modern intercom systems use unusual types of cable. The most obvious of these is Aiphone video which generally utilises ‘KB wire’. This is a parallel conductor 2core 0.9mm diameter cable with a polyethylene sheath. IT IS NOT CAT 5. The system has been designed to ensure optimal performance on the recommended cable. When a non recommended cable is used, the system performance may be degraded. This is NOT covered under warranty.


  • Door station
  • Internal station
  • Power supply
  • Cable


The cable is often overlooked and must be removed from the equation. The simplest way to do this is to connect the door station to the master internal station with a known good SHORT length of cable. This must be done as a diagnostic measure. Always ensure you have checked all of the above fault possibilities before ringing me for tech support.