Success story

Nexans is one of the suppliers alarming Södertälje hospital

The Rescue Service disallowed the fire protection at Södertälje Hospital. Now, category Data in Sundbyberg has installed a complete protection where a large part of the cables are from Nexans. Overall, it has been installed twelve thousand meters of cable to every room in the hospital to be covered by the alarm.

The Rescue Service couldn´t accept that it only was the escape routes that were alarmed at the hospital. They demanded alarms in every room, even halls, restrooms and storages.

This meant that most of the vital parts of the system had to be replaced. Old ionizing detectors were replaced by optical, most of the cabling was replaced and the numbers of signaling devices with red and white lightning and sirens were increased. In addition to that the alarm control panel was expanded with more exit circuit cards to be able to handle all the new devices.

Larmat på sjukhusThe red cables of the fire alarm system is hanging in sheats and tubes, joined in a central net with a ten conductor, which then branches into a two conductor and then to detectors and signaling devices.  A large part of the cables are Nexans fire resistant Alsecure that resist a fire for at least 30 minutes. All the alarm cables are halogen-free and flame resistant, which means that they do not spread toxic smoke or transports the fire through walls.

Twelve thousand meters of cable

The new fire alarm system has required twelve thousand meters of new cable, although modern technology has made it possible to link more signaling devices for each cable loop and thereby reducing the need for cable.

The Alarm system cables are placed separately, mostly tied below the cable ladder that is upholds the hospital power supply and other telecom cables. Alternatively, they are in a separate ducting gutter and not on the cable ladders. This to prevent damaging the cables for the fire alarm while installing new cables or while repairing existing cables.

It demands more exprience

To build a fire alarm system in a hospital is technically no more difficult than building it in at another property, but it demands more experience of those performing the work. They have to know what a technical specification means and have understanding for the administrative regulations. Installers must also understand the property manager rules, understand what is ordered and fast inform if something do not match the drawings. It is very important to be careful with the detail plan. Everything should be reviewed on site in advance to be sure of how the work will be carried out in practice.

For fire alarms cables are better than wireless systems. Wireless systems require a sender and a receiver that reaches through walls. If the building has two concrete walls it will not work. Every remodeling, for example build or demolish a partition wall, means that you have to enter new information. Additionally, wireless information can be disturbed.