Distribution Board
Helps Keep Divers’ Pressure
Stable
K Air condensation-free IP65
rated distribution boards
from Spelsberg have proven
themselves on one of the
world's most demanding
applications, decompression chambers for
deep sea divers.
A
The Bends, or decompression sickness, is
one of the greatest fears for all divers. If
they rise from great depths too quickly, the
decompressing of their bodies as the water
pressure reduces can cause gas bubbles to
form in their bodies, blocking blood flow
and causing cellular damage.
To prevent this, professional divers
often prefer to decompress slowly in
pressurised chambers. In fact, some divers
are so busy that they live in the pressure
chamber every day while they are on shift:
eating, sleeping and relaxing between
dives, rather than risk compressing and
decompressing every time.
In essences, there are two type of
decompression chambers: those
integrated into the design of a divers'
support ship as it is built and 'modular'
systems, which are designed to be deck-
deployed on existing work vessels and can
be quickly removed and re-installed on
other vessels. The latter are typically 9-12
man systems and fitted with a diving bell
which is used to lower the divers to their
working depths.
Naturally, the engineering systems that
support the decompression chambers
have to be completely reliable because
lives are at stake. So, when it comes to
the electrical systems, only the best
equipment will do.
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PECM Issue 28
However, there is a something of
a dilemma to overcome. Electrical
systems need to be kept dry, in a marine
environment this is naturally very difficult.
Items like distribution boards need to be
sealed to IP65, or another similar standard.
Of course, electrical equipment warms up
when it is in use and cools down when it is
not, so inside a sealed box the air pressure
will raise and lower, causing moisture to
precipitate out onto the colder surfaces.
Spelsberg overcame this problem with
the introduction of the AK Air distribution
boards range, which is fitted with special
air vents to maintain equal internal and
external pressures. The units have proven
themselves many times in demanding
applications in industry and agriculture,
indoors and outdoors, in hot climates and
cold. The sea is one of the most hostile
environments in which man works, yet the
AK Air distribution boards reliably protect
the lives of the brave men and women in
the saturation chambers.
Chris Lloyd MD of Spelsberg UK says: "You
have to admire the divers who put their
lives on the line every time they go to
work. Supplying electrical equipment for
their critically important decompression
chambers is a very responsible
undertaking, but it is also a privilege."
The AK distribution box design is certified
to EN 60670-24. EN 60670-24, which is also
known as VDE 0606-24, and establishes
special requirements for acceptance of
protective devices and similar energy-
consuming devices for fixed local electrical
installations. The AK Air is for installations
with a measured voltage up to 400V and
feed current of up to and including 125A.
It has a number of design features that
make it easy to install and operate. For
instance, there are a number of flange
options including smooth and knock-out
versions to enable variable cable entry
configurations, while the hinged front
window has ergonomically shaped grips
for simple opening and replacement of
door end stops.
The internal mounting rail is height-
adjustable, allowing easy accommodation
of different sized electrical components.
It can be used with M50 combination
connectors or Schuko sockets, and its
three-point- and exterior installation
options allow a number of different
mounting options.