Flexit L4 X User manual

User Manual
FLEXIT L4 X/TT
L7 X/TT
Air Handling Unit
Loft Models with Heat Recovery
94122E-05
2005-10

2
Contents
1 Important Safety Instructions .................................................. 3
2 Method of Operation - System .................................................3
3 Operation - Control....................................................................4
4 Troubleshooting.........................................................................5
5 Cleaning - Maintenance ............................................................5
6 Overview Drawings....................................................................7
6.1 Overview Drawing, L4 X/L4 X TT...................................7
6.2 Overview Drawing, L7 X/L7 X TT ..................................7
7 Technical Data ...........................................................................8
7.1 Technical Data, L4 X/L4 X TT.........................................8
7.2 Technical Data, L7 X/L7 X TT.........................................8
8 Physical Dimensions..................................................................9
8.1 Dimensioned Drawings, L4 X/L4 X TT...........................9
8.2 Dimensioned Drawings, L7 X/L7 X TT...........................9
9 Unit Adjustment Options ......................................................... 10
9.1 Adjustment ................................................................... 10
9.2 Control Card Adjustment Options ............................... 10
10 CE Declaration of Conformity...................................................11
Symbols Used
This product has a number of symbols that are used to label the product itself and in the installation and user
documentation. Here is an explanation of some of the commonest symbols.
Symbols for units/electric heating
Our products are subject to continuous development and we therefore reserve the right to make changes.
We also disclaim liability for any printing errors that may occur.
EXTRACT AIR
OUTDOOR AIR
SUPPLY AIR
EXHAUST AIR
EXCHANGER/SUMMER
CASSETTE
HEATING THERMOSTAT
DANGER! ELECTRICITY
DANGER! DO NOT TOUCH
TRANSFORMER
ADJUSTMENT
EXTRACT
AIR STAGE 2
TRANSFORMER
ADJUSTMENT
SUPPLY
AIR STAGE 2

3
1 Important Safety Instructions
To reduce the risk of fire, electric
shock or injury, read all the safety
instructions and warning texts
before using the unit.
• This unit is only designed to handle
ventilation air in buildings.
• It must not be used to extract combustible
or flammable gases.
• Remove the power plug before commencing
any service and maintenance work.
• Before you open the door, the unit must be dead and
the fans must be given time to stop (min. 2 minutes).
• The unit contains heating elements that must not be
touched when they are hot.
• The unit must not be operated without the filters being
in place.
• Follow the user manual precisely.
To maintain a good indoor climate, comply
with regulations and avoid condensation
damage, the unit must never be stopped
apart from during service/maintenance or in
connection with an accident.
2 Functional Description
In the cross exchanger HR-X, the cold outdoor air and
the warm extract air “cross” each other without coming
into direct contact with each other. With this principle,
60-70% of the heat in the extract air will be transferred
to the supply air. In addition, a thermostat-controlled
heating element EB1 will ensure that the supply air has
the desired temperature. This supply air is passed via
ducts and valves to living rooms and bedrooms. The
extract air is extracted either from the same room or via
door gaps/overflow gratings to toilets and wet rooms.
The used air is passed via a duct system back to the
unit, emits heat as stated above and is blown out of the
building via a roof hat or wall grating.
Heating Elements
The heating elements are protected against overheating
by overheating thermostats F20/F21, which switch off
at 65°C. As an additional safety measure, overheating
thermostats F10/F11 switch off at 80°C. The overheating
thermostats can be reset manually by pressing the
white button. They are located at the front on the top
of the unit. They are accessible by opening the doors
and removing the plastic cover that covers the access
opening. See the label - RESET. The reset button is
located on the innermost panel a little way inside the
opening.
B1 SUPPLY AIR TEMPERATURE SENSOR
B6 THERMOGUARD
EB1 HEATING ELEMENT
EB2 PREHEATING ELEMENT
F10/F11 OVERHEATING THERMOSTATS
F20/F21 OVERHEATING THERMOSTATS
FI1 SUPPLY AIR FILTER
FI2 EXTRACT AIR FILTER
HR-X CROSS EXCHANGER
M1 SUPPLY AIR FAN
M2 EXTRACT AIR FAN
This is purely a ventilation system and not a heating system. The home must be heated in the
normal manner. The heat gained from heat recovery must be seen in relation to a situation in
which the extract air is blown right out of the home without recovery.
Frost Protection
The unit is fitted with a special thermoguard for
maximum utilisation of the heat recovery function and
maintenance of balanced ventilation. The thermoguard
has a sensor rod B6 with a dual function. This is located
in the exchanger cassette’s extract air duct and has
an NTC element to check the temperature and an
indicator to register condensation water.
If the extract air is dry, the thermoguard will ensure
that the unit works normally down to an outdoor
temperature of approximately -15°C. At lower
temperatures, it will produce an impulse to activate
the frost protection function. This function will be
repeated periodically until the exchanger cassette’s
temperature is sufficient to prevent freezing. If the
extract air is damp, this function will start at an
outdoor temperature of approximately - 8°C. The frost
protection function operates as follows:
- The preheating element EB2 is activated.
- When this does not produce sufficient frost
protection, the speed of the supply air fan M1 is
reduced.
System Drawing
B1
FI1
F10 F20
HR-X
B6
M1 M2
EB1
EB2
FI2
F11 F21
P1
Extract air
Supply air
Outdoor air
Exhaust air
!
Troublesome thermostat

4
3 Operation - Control
The speed of the fans in the unit is
controlled from a separately mounted SP30
control switch. Depending on the operating
situation, the fan speed is set to the desired
level.
MIN stage: Used when less ventilation than
normal is required.
NORMAL stage: Normal operating ventilation.
This is the position for daily
operation.
MAX stage: Used when increased ventilation
is required in wet rooms or
throughout the flat. Must be
used during and for a while after
showering and clothes drying, for
example, to avoid condensation
in the ducts.
SP30 Control Switch for Electronic Automatic
Control with a Thermoguard
This contains the following functions:
- Right pressure switch (fan symbol) to choose
between min, normal and max speeds with an
indicator lamp to show which speed stage is active.
- Left pressure switch (+ symbol) to choose heating
OFF/ON. This switch is used to switch heating off/on
(disconnected during the warm part of the year).
The heating thermostat (item 4/Chap. 6 - see
label on page 2) is factory-set to 20°C in the unit.
It is located outside the unit (on the top of the
unit) and should not be set to over 25°C. It can be
adjusted with a flat screwdriver. The sensor for the
thermostat is located in the supply air duct. Some
heat loss up to the valves must be expected where
ducts pass through a cold environment.
- Red lamp (!): Slow flash: Filter must be
replaced (provided that a
pressure guard is installed).
Fast flash: Overheating
thermostat triggered or
thermoguard not connected.
Permanently on: Both errors
- Green lamp (+): This lights when the heating
switch is in the ON position.
- Yellow lamp (°C): This lights when the heating is
active (the element is heating).
If the unit is in temporary automatic frost protection
mode in the winter, the unit will not react to a change in
speed before the frost protection function has ceased.
If there is a power cut, the until will auto-
matically be set to Normal position and with
active heating when it restarts. This means
that the heating element will heat if there is
a need for heating.
Red
Green
Yellow

5
4 Troubleshooting
FAULT DO THE FOLLOWING
If the fans are not working or cannot be
adjusted
• Check that the power plug is correctly inserted in the power point.
• Check that the fuses in the electrical cabinet are switched on.
• The overheating thermostat(s) (item nos. 7, 8/ Chap. 6 General
Drawings) may have been triggered. Remove the white plastic
cover and press in the white reset button.
• Check that the thermoguard (item no. 3) is connected.
If the supply air feels too cold • Check that the heating switch is on and a summer cassette is not
loaded.
• The heating thermostat (item no. 4) can be set to a higher
temperature.
• Check that the thermoguard (item no. 3) is connected.
• The overheating thermostat(s) (item nos. 7, 8) may have been
triggered. Remove the white plastic cover and press in the white
reset button.
• Check that the heating switch is activated
If the air flow rate has been seriously reduced • The filters (item nos. 1, 2) may be clogged by dirt. Clean or re-
place them. See under “Cleaning - Maintenance” below.
• The grille in the outdoor air cap may be clogged. See under
“Cleaning - Maintenance”.
If none of this helps, please contact your supplier for service. Please state the serial number on the rating plate inside
the unit (open the door).
5 Cleaning - Maintenance
Before opening the door of the heat recovery system or carrying out maintenance on the kitchen hood: switch off the
heat, let the fans continue for three minutes to remove hot air, remove the power from the unit and wait 2 minutes
before opening the doors.
Doors: Opened by loosening both eccentric hooks and releasing the hooks. The doors can then be completely removed.
Fans: Item nos. 9 and 10/Chap. 6. General Drawings. The fans normally do not need to be inspected.
If necessary, they can be cleaned with a small brush and compressed air, if possible.
NB! Do not use water.
Disassemble the fans as follows:
L4: Pull out the quick-release contacts. The fan with the visible quick-release contact is loosened by unscrewing the 4
screws in the round motor plate and carefully pulling the motor out of the motor housing. For the fan with the visible
intake opening, the screw for the rail in the side wall must be removed and the rail pushed down as far as possible. The
entire fan housing can then be released and turned around. The fan can then be released with 4 screws, like the first
fan.
L7: The fan with the visible quick-release contact is loosened by unscrewing the 3 screws in the end of the fan housing
and carefully pulling the fan out. For the fan on which the screws are on the opposite side, the entire fan housing must
be loosened by unscrewing the mounting rails (2 screws) on each side of the fan, thus releasing it. The fan can then be
released with 3 screws, like the first fan. The fan can be disassembled most easily if the exchanger cassette is removed
first.

6
Filters: To preserve a healthy indoor environment, it is important to change filters when they are dirty. Dirty
filters lead to:
Increased air resistance in the filter – less air in the home – the risk of bacterial growth in the filter
– in the worst case scenario, the system can be damaged.
How often the filters need to be changed depends on the degree of contamination of the air where they
are installed. In general, the filters need to be changed once a year, preferably in the autumn (after the
pollen season). In areas with a lot of dust and contamination, the filters should be changed in the spring
and autumn. The supply air filter that cleans the outdoor air (2) consists of a prefilter (EU-3 coarse filter)
and a compact filter (EU-7 fine filter). Remember the sequence from outside: steel grille – prefilter
– compact filter. The supply air filter is a bag filter on the L7. The filters are pushed in place in the fixing
rails. The extract air filter that cleans the extract air (1) is an EU-3 filter (coarse filter) and is located on
a separate rail. It is recommended that you order a filter subscription to ensure full benefit from the
system and the cheapest prices.
Order no. for a complete set of filters: L4 X/TT- 12318, L7 X/TT - 12313
Exchanger
cassette: Should be checked roughly once a year for dust and dirt in the air ducts. First remove the
thermoguard (3) and carefully pull the cross exchanger (11) out. If cleaning is required, place it in a
bowl with warm soapy water (NB! not soda) and finally flush it through with warm water. Clean the
thermoguard separately with a dry cloth. When removing/installing the exchanger cassette, it is
important to ensure that both the cassette and the sensor rod are located correctly and that the
cable plug is inserted in the contact. The thermoguard must be located 6 cm from the top of the
exchanger cassette and in the centre of the exchanger cassette. Located on the side facing the
extract air filter.
Valves and
duct system: The valves should be cleaned at least once a year.
The duct system should be cleaned at least every 10 years.
Outdoor air
intake: Check once a year that the grille is not clogged with leaves, dust and dirt.
Roof hat: Check once a year that the drainage gap at the bottom is not clogged with leaves. This applies only if
the system has a roof hat.
Summer
operation: During the warm part of the year (outside the heating season), there is no need to recover heat. The
exchanger cassette can be replaced with a summer cassette that is available as an accessory. This is
pushed into place where the cross exchanger (11) is located. This allows the outdoor air to enter the
building directly without heat recovery taking place. The thermoguard (3) must then be transferred
to the summer cassette. Its location is shown on the label. NB! At the same time, the heating must be
switched off (press the left switch (+) on the control panel so that the green light goes out) to avoid the
heating element switching on unnecessarily.
Remember to reverse this again in the autumn.
Drainage: At the base of the unit there is a condensation water drain (14) that conducts condensation water to
the waste water drain. It is important that this drain is always open, in good condition and well insulated
where it is exposed to frost. It is also recommended that you keep an eye on the drainage system to
avoid any leaks occurring.
Lack of cleaning as prescribed will increase the risk of fire in the event of an accident.
Cross
exchanger
Thermoguard
Loft model filter location
Supply air ilter:
Prefilter and
compact filter
Extract air filter:
Flat filter with cardboard frame
!
Position of the troublesome thermostat

7
6 Overview Drawings
6.1 Overview Drawing, L4 X/L4 X TT
6.2 Overview Drawing, L7 X/L7 X TT
Item Part
no.
1 G3 extract air filter
2 F7 supply air filter
3 Thermoguard
4 Heating adjustment
5 Preheating battery
6 Overheating thermostat, preheating
7 Overheating thermostat, heating
8 Supply air fan
9 Extract air fan
10 Cross exchanger, L7/TT
11 Control switch
12 Control unit
13 Drainage outlet
11
14
610 11 9
1
13 312
54
8
2
7
Supply air
Outdoor
air
Extract air
Exhaust
air
1
8
810 9
2
12 3
11
5
46
713
6
Supply air
Outdoor air
Extract air
Exhaust air
Item Part
no.
1 G3 extract air filter
2 G3 + F7 supply air filter
3 Thermoguard
4 Heating adjustment
5 Preheater
6 Heating battery
7 Overheating thermostat, preheating
8 Overheating thermostat, heating
9 Supply air fan
10 Extract air fan
11 Cross exchanger, L4/TT
12 Control switch
13 Control unit
14 Drainage outlet

8
7 Technical Data
7.1 Technical Data, L4 X/L4 X TT
L4 X L4 TT X TT
Rated voltage 230 V/50 Hz 230 V/50 Hz
Fuse 10 A 10 A
Rated current, total 8.7 A 8.7 A
Rated power, total 1980 W 1980 W
Rated preheating power 975 W 975 W
Rated power, fans 2 x 165 W 2 x 165 W
Rated power, electric batteries 1650 W 1650 W
Fan type F-wheel F-wheel
Fan motor control Transformer Transformer
Max. fan speed 2230 RPM 2230 RPM
Standard automatic control SP30 SP30
Filter type (SUP/EXTR) F7/G3 F7/G3
Filter dimensions, SUP (WxHxD) 255x220x50 mm 25x220x50 mm
Filter dimensions, EXTR (WxHxD) 255x220x20 mm 25x220x20 mm
Weight 36 kg 41 kg
Duct connection Dia. 160 mm Dia. 160 mm
Height 605 mm 605 mm
Width 1000 mm 1000 mm
Depth 350 mm 350 mm
7.2 Technical Data, L7 X/L7 X TT
L7 X L7 X TT
Rated voltage 230 V/50 Hz 230 V/50 Hz
Fuse 16 A 16 A
Rated current, total 10.7 A 10.7 A
Rated power, total 2460 W 2460 W
Rated power, electric battery 2000 W 1000 W
Rated power, fans 2 x 230 W 2 x 230 W
Rated preheating power 1000 W 2000 W
Fan type F-wheel F-wheel
Fan motor control Transformer Transformer
Max. fan speed 2120 RPM 2120 RPM
Standard automatic control SP30 SP30
Filter type (SUP/EXTR) F7/G3 F7/G3
Filter dimensions, SUP (WxHxD) 394x223x250 mm 394x223x250 mm
Filter dimensions, EXTR
(WxHxD) 394x223x20 mm 394x223x20 mm
Weight 66 kg 72 kg
Duct connection Dia. 250 mm Dia. 250 mm
Height 625 mm 625 mm
Width 1170 mm 1170 mm
Depth 465 mm 465 mm

9
8 Physical Dimensions
8.1 Dimensioned Drawings, L4 X/L4 X TT
8.2 Dimensioned Drawings, L7 X/L7 X TT
All dimensions in mm
All dimensions in mm

10
9 Unit Adjustment Options
Before opening the door of the heat recovery system or carrying out maintenance on the kitchen hood:
switch off the heat, let the fans continue for three minutes to remove hot air, remove the power from
the unit and wait 2 minutes before opening the doors.
9.1 Adjustment
The speed of the unit at the normal stage must be set to the voltage specified in the “Documentation of Ventilation
Data” form that is enclosed with the ventilation drawings from the company responsible for project planning. Open the
door and unscrew and remove the cover of the automatic control compartment. The transformer is then visible and
the cables marked 1 23(as shown on page 2) can be switched over to the specified voltage level.
Extract air Supply air
L4 X / L7 X: The automatic control compartment is on the top of the unit. Factory setting 150 V 170 V
9.2 Control Card Adjustment Options
Bold type shows the standard factory setting. All settings can be combined.
With the standard settings, the unit functions in such a way that heating is available if required with normal operation,
while heating is switched off with frost protection operation, when the preheating element takes over.
If both elements are required for heating in cold areas during frost protection operation, switch 1 must be switched to
OFF. Please note that the unit’s rated power will then increase with the power of the preheating element. On the L4/S4,
13 A fuses must be used in such cases.
Cross unit control card
Dipswitch
no. OFF ON
1Heating is not affected with
frost protection
Heating is switched off
with frost protection
2 Heating and preheating
function normally
Heating and preheating
are switched off at the min
stage
3Not affected with night-time
temperature reduction
Temperature is reduced
by 3°C with night-time
temperature reduction
4Not affected with nighttime
temperature reduction
Fan speed is reduced
to low with nighttime
temperature reduction
5Preheating element is used
only for frost protection
Preheating element is also
used for heating
6 Must be in this position Not used
!
Dipswitch

11
10 CE Declaration of Conformity
This declaration confirms that the products meet the requirements in the following Council Directives and standards:
89/336/EEC Electromagnetic compatibility (EMC)
73/23/EEC Low-voltage Directive (LVD)
NEK EN 60335-1 :94 + A11:95 + A1:96 + A1:96 + A12:96
54014:93, EN 61000-3-2/-3:95, EN 55014-2:97
Manufacturer: FLEXIT AS, Televeien 15, N-1870 Ørje
Equipment group: Ventilation units for installation in ducts
Type: VG 400: 1997
VG 700: 1997
The product is CE-marked: Shown in the list above
FLEXIT AS 02/05/2001
Pål J. Martinsen
General Manager
The right to give notice of lack of conformity applies to this product in accordance with the existing terms of sale,
provided that the product is correctly used and maintained. Filters are consumables.
The symbol on the product or on its packaging indicates that this product may not be treated as household waste. Instead it shall be handed over
to the applicable collection point for the recycling of electrical and electronic equipment.
By ensuring this product is disposed of correctly, you will help prevent potential negative consequences for the environment and human healthe,
which could otherwisw be caused by inappropriate waste handeling of this product. For more detailed information, please contact your local city
office, your household waste disposal service or the shop where you purchased the product.
Notice of lack of conformity as a result of incorrect or defective installation must be submitted to the installation company responsible.
The right to give notice of lack of conformity may lapse if the system is used incorrectly or maintenance is grossly neglected.

Flexit AS, Televeien 15, N-1870 Ørje www.flexit.no