Page 25 - Uninterruptible Power Supplies

Standby Power Generating Sets
Standby Power Generating Sets 23

to allow entry (strictly controlled) for occasional cleaning or inspection.
At the fill point there should be an audible warning which sounds when
the bulk tank is full.
When fuel is delivered to the bulk tank, care has to be taken to avoid
introducing foreign material into the tank and there should be arrange-
ments for earthing the delivery vehicle to avoid a discharge of static
electricity during delivery. A coarse filter should be installed in the
pipeline to the service tank, before the electric pump or any other item
in the pipeline.

Fire Precautions
A risk assessment should be undertaken which considers the results of
an engine room fire. Local regulations regarding the storage of fuel vary
and at an early planning stage the installation should be discussed with
the local planning and fire authorities so that the installation can be
planned for compliance. In the United Kingdom the planning authority
is the first point of contact, they will effect an introduction to the fire
authority. The fire authorities are mostly concerned with escape routes
from the building, but the occupier should consider wider implications
such as the potential loss of the building and its contents, the loss of busi-
ness records, and the loss of profit due to the inability to operate after
a fire.
Where the daily service tank is supplied by gravity from a bulk tank
there is usually a requirement to install a fire valve, closed on receipt
of an alarm indicating a fire within the engine room, between the bulk
fuel tank and the engine room. This prevents fuel entering the area and
feeding the fire.
If the generating set is installed within an occupied building there may
be a requirement to drain the daily service tank within say 1 min of
receipt of an alarm indicating a fire within the engine room. This
requires a jettison pipe connection to the daily service tank and a jetti-
son valve opened on receipt of a fire alarm. If the bulk tank is below the
service tank fuel can be returned to it by gravity, but if not, a jettison
tank (normally empty) outside of the engine room and below the level of
the daily service tank will be required. The jettison tank will require an
air vent which may be piped back to the service tank or may be termi-
nated in a safe area. There must be clear indication, in an appropriate
part of the building, of any liquid within the jettison tank and procedures
must ensure that it is emptied without delay. A method of emptying the
jettison tank should be available, if no drain cock is available this could
be by using a portable electric or semi-rotary hand pump.
Fire valves are usually of the free-fall gravity-operated type, electri-
cal power for operation may not be available when required. Within the

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