Lift Communication Systems

Terminology

Some communication products can be somewhat confusing, so we have detailed and explained the more commonly used definitions.

Autodialler

An autodialler is designed to provide trapped passengers with easy hands-free connection to emergency help. The trapped passenger simply presses the emergency button inside the lift car and the autodialler automatically connects to one of a number of pre-programmed emergency telephone numbers.

The autodialler provides reassurance and instructions by means of a speech synthesised voice whilst it is calling the first pre-programmed number. The call receiver is guided by built-in voice messages. The trapped passenger and call receiver can then speak with each other. If the call is not answered, the autodialler will continue to dial each of the pre-programmed numbers in round robin sequence until it reaches a human operator who presses the key correctly (i.e. not an answering machine)

Inductive Loop

One of the many requirements of EN81-70 Lifts for Disabled Use is that passengers with limited hearing can hear emergency messages and operator instructions when trapped in a lift. This is achieved via the installation of an inductive loop, which enables sounds to be heard more clearly by reducing or cutting out background noise. It consists of a cable that encircles the listening area, which is fed by a current from the loop amplifier.

The amplifier gets its signal from a microphone placed in front of a person speaking or by means of a direct connection from another sound source, such as a sound system. The resulting electric current in the loop produces a magnetic field, which corresponds to the sound. Passengers with hearing aids simply switch the aid to setting 'T', which enables them to pick up this magnetic field. They are then able to hear the emergency message instructions clearly, without the usual interference or distracting background noise. Different size inductive loops are available depending on the range of detection required.

Pictogram

EN81-70 Lifts for Disabled Use requires that trapped passengers must receive a visual validation of an alarm call. This is achieved via the use of a pictogram, which consists of two legends which are illuminated by an LED light source. A yellow legend illuminates when the alarm call has been activated, followed by a green legend when the call has been received.

GSM Unit

A GSM unit enables an autodialler to operate via the mobile phone network without the need for a BT land line. Not only is this cost effective (as it eliminates the BT line and equipment rental charge), but GSM units can prove invaluable when the lift service is required prior to the installation of the phone line. A mobile phone SIM card is placed in the GSM unit, which is connected to the autodialler.

When the emergency button in the lift car is pressed, a signal is sent to the GSM unit, which calls the outside emergency helpline via the mobile phone network.

Fire Fighting Intercom System

The fire fighting lift intercom system has been developed in accordance with BS EN81-72 and BS5588 Part 5. In its simplest form, it comprises of a fire service access landing station (FSAL), a lift car station and a motor room station. It is powered by a main control unit (containing a power supply and back-up battery), which is normally situated in the motor room.

In everyday situations the system will remain in idle mode, however, once activated by the fireman's key switch on the FSAL, a three way communication link between the FSAL, the lift car station and the motor room station is automatically established.

The lift car station always operates hands-free, however the FSAL and motor room station each have a talk button which is used in a 'press to talk', 'release to listen' manner. The three way communication link detailed above can be expanded to include additional stations enabling others to participate in the conversation. This could include a fire command centre or a security control room.

Once the fireman's switch has been activated, the lift car automatically moves to the FSAL level, and remains under the control of the fire officer until normal service has resumed.

Voice Evacuation Intercom System

The voice evacuation intercom system has been developed in accordance with BS5588 Part 8. In its simplest form, it is a system that is used for the evacuation of people with impaired mobility in the event of a fire or emergency, under the direction of management, authorised persons or fire fighters.

It comprises a final exit storey control panel (FES control panel), evacuation control stations situated on each landing and a lift car station. It is powered by a mains control unit (containing a power supply), which is normally situated in the motor room.

Once activated by the Euro key switch on the FES control panel, the lift controller automatically switches to evacuation mode, sending the lift car directly to the FES level. An interactive two way communication link is established between the FES control panel and the lift car and also the FES control panel and the evacuation landing stations.

At all levels, the evacuation landing stations start to flash, as does the lift car station. The lift can now answer normally to car calls for the assisted evacuation of people with impaired mobility.

The evacuation mode is normally stopped upon the fire fighter's arrival when the lift is switched to fire fighter's mode.