R&M Data Center Handbook

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Fire and Lightning
Quite a few security measures that are not at all obvious can be taken
when it comes to fire protection. An obvious first step that makes sense is
to implement the required precautions in the rooms or buildings to be
protected. This includes smoke and heat detectors, flame sensors,
emergency buttons as well as surveillance cameras that sound alarms
when fire erupts, or ensure that security officers become aware of this
situation faster.
In addition, one must ensure that fire department reaction time is as short
as possible. Companies with a fire department on site have a clear
advantage here – but it can also be of advantage to carry out regular fire
drills that include the local fire department.
As lightning is one of the most common causes of fires, a lightning rod is mandatory in every data center building.
In addition, responsible employees should provide all IT components with surge protection, to avoid the damage
that can occur from distant lightning.
Structural measures can also be a help: When constructing a data center, some architects go so far as to use
concrete that contains metal, so a Faraday cage is produced. This ensures that the IT infrastructure is well
protected against lightning damage.
Other Causes of Fires
Lightning is not the only cause of fires. Other causes are also associated with electricity; furthermore, overheating
and explosions play an important role in connection with fire. Among other causes, fire that is started by electricity
can erupt when the current strength or voltage of a power connection is too high for the device that is running on it.
Defective cable insulations also represent a danger, namely they provide sparks that can accidentally ignite
inflammable materials that are located nearby. The parties responsible should therefore make sure that not only is
the cable insulation in order, but also that as few flammable materials as possible exist in the data center. This tip
may sound excessive, but in practice it is often true that piles of paper and packaging that are lying around,
overflowing wastepaper baskets and dust bunnies and similar garbage make fires possible. Regular data center
cleaning therefore fulfills not only a health need, but also a safety need. In connection with this, IT employees
should also make sure that smoking is prohibited in data center rooms, and that a sufficient number of fire
extinguishers are available.
Other prevention methods can also be implemented. These include fire doors, and cabling that is especially
secure. With fire doors, it is often enough to implement measures that stop the generation of smoke, since smoke
itself can have a devastating effect on IT environments. However, in environments that are at an especially higher
risk of fire, installing “proper” fire doors that are able to contain a fire for a certain amount of time will definitely
provide additional benefits.
With regard to cabling, flame-retardant cables can be laid, and so-called fire barriers can be installed that secure
the cable environment from fires. These ensure that cable fires do not get oxygen and also prevent the fire from
quickly spreading to other areas.
Fire Fighting
Once a fire occurs, the data center infrastructure should already have the means to actively fight it. Sprinkler
systems are especially important in this area. These are relatively inexpensive and are easily maintained, but are
a problem in that the water can cause tremendous damage to IT components. Apart from that, sprinkler systems
provide only a few advantages when it comes to fighting concealed fires, like those in server cabinets or cable
shafts.
CO2 fire extinguishing systems represent a sensible alternative to sprinkler systems in many environments. These
operate on the principle of smothering burning fires, and therefore do not require water. However, they also bring
along disadvantages: For one, they represent a great danger to any individuals who are still in the room, and for
another, they have no cooling effect, so they are unable to contain damage caused by the generation of heat.
A further fire-fighting method is the use of rare gases. Fire extinguishing systems based on rare gases (like argon)
also reduce the oxygen content in air and thus suffocate flames. However, they are less dangerous to humans
than CO2, so individuals who are in the burning room are not in mortal danger. In addition, argon does not cause
damage to IT products. Drawback: These systems are rather expensive.
Page 76 of 156 © 08/2011 Reichle & De-Massari AG R&M Data Center Handbook V2.0