Loudspeaker line isolator

  Fault Isolator Module




Automatically opens circuit when the DC-voltage carrier drops below threshold on loop. Fault Isolator Modules (FIM) should be spaced between groups of loudspeakers (maximum 25, please refer to your national standards organisation for detailed information) in a loop to protect the rest of the loop. If an open or a short occurs between any two isolators, then both isolators immediately switch to an open circuit state and isolate the faulty group of loudspeakers between them. The remaining isolators, the T-branch loudspeakers of the affected FIM’s and the loudspeakers on the loop remain fully operational.


During fault status, the Loopdrive Booster, LDB, is feeding both loop-branches simultaneously and the fault is indicated by the status LED’s on both FIM’s and LDB’s.


(Optional: Detailed information is provided via dedicated PC application over RS485 from the LDB).

The LED indicator(s) on the FIM and LDB are flashing with intervals to indicate the error. The FIM restores the faulty partition of the Loop-branch-lines to normal condition when the short or open circuit condition is removed and a general reset command is given by pressing the RESET button on the corresponding LDB.

The FIM is equipped with a power capacitor that is charged by the LDB and has enough capacity to run at least two measurement cycles without the need for re-charging.

4evac-louspeaker line isolator During fault status, the Loopdrive Booster, LDB, is feeding both loop-branches simultaneously and the fault is indicated by the status LED’s on both FIM’s and LDB’s.
Features and Benefits
  • EN54-17 certified;

  • At least two measurement cycles without the need for re-charging ;

  • Patent Redundant loop Technology using sophisticated Field Isolator Modules – FIM - and central Loop-Drive-Boosters – LDB; 

  • Considerable cost savings in cabling and installation because in most cases fire-retardant cabling and installation (E-XX) is not needed and/or speaker loops can be extended with preservation of the systems integrity;

  • Isolates and reinstalls the loop maximum functionality within 4 seconds after detection of a fault;

  • Using ordinary 2-wire loudspeaker cabling. (Ground wire connection is available – depending on national standards requirements);

  • Higher level of system availability for VACIE applications;

  • Works with all commercial 100 Volt loudspeaker with DC-blocking capacitor and VACIE systems;


  • Service mode for live FIM installation and testing; 

  • FIM-Tracking mode for exact fault locating;

  • GUI PC-interface with enhanced monitoring fields


  • Protection against cable short, wire-to-wire, and cable open;

  • Protection against EARTH leakage to ground and EARTH loop fault;

  • Maximum of up to 200 FIM’s on a single LDB;

  • Maximum of 255 LDB’s in one system;

  • Maximum of 32 LDB’s sharing a single DIN-rail power distribution element;

  • Maximum audio ring-load: 100 V(RMS)/800 Watt (Audio).

  • Cost saving WAGO push-terminal installation connectors on FIM; 

  • Maximum cable core diameter of installation cable: 2 x 2,5 mm2;

  • Maximum loop length: 1000 m.


Alternative style loops:

The FIM -loudspeaker line isolar- is used at it’s T-Branch to feed a single loudspeaker or a group of loudspeakers to limit the on-going effect to the devices on the main loop. 


The maximum number of loudspeakers between

FIM’s is not limited within the maximum LOOP-load of 800 W, however, National standards may limit the amount of loudspeakers between Isolators.


Industrieweg 87
2651 BC Berkel en Rodenrijs
The Netherlands
P.O.Box 2650 AA Berkel en Rodenrijs
+31 88 1428600
+31 (0)6 - 835 71 669



General: info@4evac.com

Sales: herman.benning@4evac.com

Technical: daniel.damps@4evac.com

Order handling: sigrid.dejong@4evac.com

Operational: albert.vanderhout@4evac.com


4EVAC is a trade name of Hacousto Holland B.V.

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