• BSE

The Fireman Intercommunication System—The Two-way EVC System

As the previous post has shown, effective communication is key to saving lives during emergencies. The equipment that enables our firefighters to do their job better, therefore, needs to be reliable. This week, we shall focus on the second kind of Emergency Voice Communication (EVC) System: the Fireman Intercommunication System (Two-way type).

  • It provides two-way communication between the remote handsets and the master handsets during emergencies or fire-fighting operations

  • It works through a network of telephone handsets located at designated areas in the building


As such, the following regulations require premises to have an operationally-ready and well maintained Fireman Intercommunication System (Two-way type):

  • Code of Practice for Fire Precautions in Buildings 2018 (Fire Code 2018)

  • Code of Practice for Emergency Voice Communication System in Buildings (SS 546: 2009 - formerly CP 25: 1999)

Where is the EVC System - Two-way located?

  • The Fire Command Centre (control station for two-way EVC Systems)

  • Common areas such as outside protected corridors and lobbies

  • It can be placed in cabinets or exposed

Who is responsible for the EVC System - Two-way?

  • Building Owners and Council Members are responsible by regulation

  • Fire Protection Specialists, like BSE, MCST Managing agencies, and/ or technicians are engaged to assist Building Owners and Council Members

Basic features of the EVC System - Two-way

  • Control station - consisting of a microphone, selector switches to operate all loudspeakers, audio and visual fault indicators for the equipment, switch to silence the audio fault indicator, manual activation switch for pre-recorded messages, facility to isolate background music when required.

  • A recording system of not less than 120 minutes of continuous recording duration

  • Handsets - master and remote

  • Remote handset enclosure

  • Fault monitoring

  • Power amplifiers

  • Interface with the fire alarm system

  • Battery - charger, cabinet

What kind of maintenance will the EVC System - Two-way need and how often?


According to regulations, the recommended frequency of inspection, testing and maintenance of the EVC System - Two-way in buildings is once in NOT MORE THAN THREE (3) MONTHS. However, the regulatory testing and maintenance of the EVC System - Two-way are conducted ANNUALLY, in conjunction with the Fire Alarm System and its related Fire Protection equipment.


For industrial buildings with a higher risk of fire incidents, more frequent testing and maintenance may be conducted to ensure Total Fire Safety in the premises.


Inspection procedure


Inspection checklist for the EVC System - Two-way:

On a recommended NOT MORE THAN THREE (3) MONTHS basis:

  • Check that the access to the EVC equipment is not obstructed

  • Check that all remote handsets remain unobstructed and conspicuous

  • Check that the visible indications remain readily distinguishable in ambient light conditions

  • Check that there are no fire hazards near the location of the EVC equipment

  • Check that operating instructions are available

  • Check all visible and audible indicating devices at the FCC

  • Check the standby battery power source to ensure its capacity is adequate to meet the calculated requirements

On a recommended ANNUAL basis:

  • Same as the above NOT MORE THAN THREE (3) MONTHS basis

Testing procedure


The following steps are taken to ensure the EVC System - Two-way is operationally-ready for emergencies:

  • Test the operation of the remote handset to confirm that the call is correctly received at the master handset

  • Test a different remote handset at the time of test, so that all remote handsets in the building are tested in rotation (all remote handsets should be tested at least once a year)

  • Test the handsets by transmitting calls between the remote handsets throughout the building and the master handsets at the FCC on both a party-line and private-line basis

  • Check the standby battery power source to ensure its capacity is adequate to meet the calculated requirements

  • All fault indicators should be checked by simulation of fault conditions

  • Where provided, all auxiliary functions should be tested

Next, defects are identified for recommendation and rectified in a timely manner.


Tips on having an optimum EVC System - Two-way:

  • Ensure that the interface with the Fire Alarm System is connected and working in order, in the event of an emergency

  • Ensure that the connection between the master and remote handset enables communication to be carried out from the different locations of the building

  • Ensure that all indicating devices on the master panel are working to provide information to the personnel in the FCC room to identify and give instructions with

  • Ensure that the standby power source is sufficient to operate the equipment, in the event of power failure

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