AERMEC TRA 50 Technische Bedienungs- Und Installationsanleitung Seite 16

if it is outside the water.
Formation of ice
in the circuit's pipes
The water in the pipes freezes and
begins from the levels in contact
with the walls of the pipe and the
phenomena slows down as the freeze
continues towards the centre.
The water having become ice inside the
pipes almost always cause the pipes to
burst..
To remedy this possibility the circuit can
be made in such a way that when the
system is not working the water drains
into an auxiliary tank or a self heating
cable wound around the pipes and
further protection with pipe insulators
can be installed.
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Formation of ice
in the fans
When the system is closed down in
low temperatures or snowfall, a thin
layer of ice might form between the
parts inside the fan support ring and
the end of the fan blades. If the ice
forms a single block between the fan
and the support ring, the fan will be
blocked when it is restarted and the
motor might burn out or sometimes
of one or more blades might brake. To
prevent this from happening a heating
cable might be installed outside the fan
ferrule , protected by suitable insulating
material in order to keep the steel
ring at a certain temperature and thus
prevent ice from forming.
N.B.
never cover the fan motor with covers,
roofs or protections of any other
description because in addition to being
useless (all the motors are water tight)
if operating with the air discharge
obstructed the electrical motor might
burn out..
Formation of ice
around the tower
When the ambient temperature is very
low, ice might form on the ground
immediately around the tower: this
situation may create a hazard for any
work that has to be carried out in that
area.