Isotherm BI 41, Installation And Operation Manual

Page: 8 / 23

Installation Isotherm Magnum
compressor unit
Compressor unit
The compressor unit should be fi tted in a horizontal
position in a suitable place. The unit will operate
continuously at angles of up to 30° and should
therefore be fi tted horizontally so as nor to exceed this
at full angle of heel. The unit should be screwed down
well to withstand all possible sea conditions.
Installation can often be simplifi ed if the quick-coupling
connections on the piping and the compressor unit
are screwed up tight before the compressor unit is
fi nally tightened down in its position. Do not remove
the protective caps until immediately before this is
about to be done and save them for future use if the
compressor unit for some reason must be moved. The
quick coupling connections can be turned by hand into
open position and fi rmly tightened after that with fi xed
spanners 21 and 24 mm. During the tightening, hold
the male coupling with the 21 mm spanner in position
and turn the other part, not to damage the thin capillary
tube. Tighten the couplings up hard.
Water pump
The water pump is self priming up to 2 m (6 ft.) suction
height. The power supply for the pump is reduced
down to 5 volt for low noise and long lifetime operation.
The voltage reducer set the speed of the pump
depending on water condenser temperature. after
the refrigeration system has been installed, the water
pump will at the fi rst start up run on a higher speed for
90 seconds to pick up water faster. This will happen
also when the unit has been powerless.
Sea water connection
The cooling water inlet to the pump must be connected
to a hull fi tting which allow cooling water to be fed to
the pump also when sailing in heavy weather. Suitable
hose dimension is 13 mm / ½”. A water fi lter is mounted
on the suction side. The strainer has an easy
replaceable cartridge. Clean this cartridge with short
intervals. The water outlet from the heat exchanger can
be connected to an existing hull fi tting, but must always
be open to allow a free fl ow through the system when
the pump is working.
Separate fi ttings for both in- and outlet for the
refrigeration system is always the best.
As an alternative to the sea water connection, the
fresh water tank on board can be used for cooling
the condenser/heat exchanger. If there is a fresh
water capacity of about 400 litres or more , the water
pump/condenser unit can be connected to the tank.
The heat exchange will not infl uence the fresh water
temperature, as long as the tank has 170-180 litres
or more. With less water a temperature rise of a few
degree C can be recognized.
Minimum water volume can be recommended to 140-
150 litres.
Water out
Water in
Zinc Anode
Water out
Water in
Maintenance
Maintenance of the compressor assembly is limited to
regular check-up and replacvement of the zinc anode,
cleaning water strainer and watwer pump. Change the
zinc anode at least once a year.
Drain the water system, including pump and fi lter, if
temperatures below freezing point are expected, or fi ll
up properly with anti-freeze.
001102
001103