
FHW12, FHW22, FHW32, FHW33
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FHW with the filter net FHWFN
FHW can be provided with a metal filter net to
protect the heating coil (not included on delivery).
The top/bottom lid is opened, and the filter is slid
down behind the coil in tracks for this purpose. The
filter can be reached for installation and cleaning/
maintenance from both top or bottom of the FHW.
FHW with the extra air director FHWAD
To direct the air current sideways. On delivery, FHW
is equipped with an air director for vertical direction
of the air current. The extra air director is mounted
to the FHW unit by hooking it onto the existing air
director. The louvres are individually adjustable and
are made of anoidized aluminium.
Ceiling mounting
The FHW unit, the mixing cabinet and the filter
section are mounted onto each other on the floor
and lifted up as one unit to be mounted on the
ceiling. The units should be mounted together with
screws or guides.
Water connection
The installation should be carried out by a certified
installer. Pipe connections can be made on either
side of the FHW unit. They must however, not be
connected pointing upwards or downwards.
Connection pipes are made of copper for
soldering or clamp ring pipe connection.
Note! Be careful while connecting the pipes to
prevent pipe damage and water leakage.
Prior to use, the pipe system should be
ventilated. An air valve should be connected on a
high point in the pipe system. Íf a draining valve is
used, it should be mounted on the outside of the
FHW unit. Air- and draining valves are not inlcuded
in the heating coil.
FHW units which can be exposed to air
temperatures below zero (for example when a
mixing cabinet is used for fresh air intake) should be
equipped with an external automatic frost protection
regulation, to ensure that the heating coil is not
damaged by frost.
Electrical installation
The electrical installation should be carried out by
a qualified electrician in conformity with prevailing
regulations. The appliance should be preceded by
an triple-pole switch with at least 3 mm breaking
gap.
The following applies to FHW12 och FHW22
only: The fan motor is connected via a cable gland in
the casing, to a terminal box inside the unit. Bottom
and top lids are equipped with hinges and are easily
opened after loosening a pair of screws underneath
the lid.
On the side of the unit there are knock-outs, 2
pcs ø 20 mm. See wiring diagrams on pages 6-8.
The following applies to FHW32 och FHW33
only: The fan motor is connected directly to the
terminal on the motor which is easily accessible
from the outside of the FHW unit. When a mixing
cabinet or a filter section is used, holes must be
made in the casing for connection cables.
All motors are equipped with a built in automatically
returning thermocontact, connected to the terminal
blocks for connection with an external thermocontact
relay (STET10B) with manual reset and an alarm
signal (auxillary contact).
Cable-glands used must guarantee the protection
class requirements.
After the electrical installation of the motor, check
the rotation of the fan. Seen from the inlet side, the
impellers should be rotating anti-clockwise.
Maintenance
To ensure performance and reliabilty of the FHW
unit, inspection and cleaning should be carried
out reguarly. Inspection should be carried out at
least twice a year. Clean the unit when needed.
During inspection the power supply must always be
disconnected.
Cleaning the fan
Cleaning intervals of the fan is due to filter (if any)
and air quality. When a filter section with a deep-
pleated bag filter is used and the indoor air is of
normal quality, the FHW unit is generally cleaned
once a year. If the impellers are not cleanded
properly, vibrations/noise can occur and severly
damage the bearings. If the vibrations/noise remain
after cleaning, please contact a certified technician.
The FHW unit, the mixing cabinet, the filter
section and the heating coil can be vaccumed from
dust.
When there are no accessories on the inlet side,
inspection of the fan can be made from the outside
of FHW. When the filter section is used, inspection
can be carried out by the inspection door on the
side of the filter section. To inspect the fan when the
mixing cabinet is used (with no other accesories on
the inlet side), the mixing box must be dismantled.
GB