S 1.26 Emergency circuit-breakers

Initiation responsibility: Head of IT, Building Services Manager

Implementation responsibility: Building Services

Consideration should be given to installing emergency circuit-breakers in rooms where electrical devices are operated in such a way that there is a higher risk of fire due to the heat dissipated by the devices, the high density of devices, or the presence of additional fire loads. Since someone will be needed to operate the emergency circuit-breakers, they can only be used in areas that are constantly or usually manned. Using an early fire detection system to trigger emergency shutdowns is much more effective for areas that are only occupied sporadically.

Operating an emergency circuit-breaker will eliminate a major source of energy of the fire which may lead to minor or smouldering fires being extinguished. At the very least, this will eliminate the risk of electrical shock while fighting the fire.

It must be taken into account that uninterruptible power supplies (UPSs) will automatically start supplying power after switching off the external power supply and that the devices connected to it will still be live. Therefore, it must be ensured when installing an emergency circuit-breaker that the UPS is also switched off and not just disconnected from its external power supply.

The emergency circuit-breaker should be installed in the room next to the entrance door (possibly together with a sign pointing out its location) or outside of the room next to the door. It must be noted, though, that an emergency circuit-breaker can also be activated accidentally or intentionally even though there is no danger present. Therefore, the emergency circuit-breaker must be protected against accidental activation by a cover.

If the fire department requires the installation of an emergency circuit-breaker, a fire department key switch can also be used to this end. This virtually eliminates the possibility of accidental or unauthorised deliberate operation of the switch.

A negative example:

A server room in a medium-sized government agency was equipped with about 10 servers, 5 laser printers, and other devices and equipment. The room was designed to provide intrusion protection using corresponding walls, doors, and windows. However, no emergency circuit-breaker was installed. There were only two locations for de-energising this room in a targeted manner: the main distribution panel of the building in the basement or the room's distribution panel. However, the room's distribution panel was installed on the wall opposite the entrance door, which makes it almost unreachable in case of fire.

Review questions:

• Has the usefulness of installing an emergency circuit-breaker been examined for all technology and IT rooms?
• When an emergency circuit-breaker is installed, was it considered that not only the external power supply, but also the UPS is switched off when the switch is operated?
• Are all emergency circuit-breakers protected against accidental activation?