NuAire MRXBOX95B-450 WC Instruction Manual

The EMC Directive
2014/30/EU
The Low Voltage
Directive
2014/35/EU
The unit must remain switched on at all times to maintain ventilation
within the dwelling. Turning the unit off will cause long term damage to
the unit and building fabric.
This appliance is not intended for use by persons (including children)
with reduced physical, sensory or mental capabilities, or lack of
experience and knowledge, unless they have been given supervision or
instruction concerning the use of the appliance by a person for their
safety. Children should be supervised so that they do not play with
the appliance.
MRXBOX95B-450 WC and 450
Mechanical Ventilation Unit with Heat Recovery and
Summer Bypass for Wall Mounting
Installation and Maintenance
27. 11. 17. Leaflet number 671617
Ducting in
ceiling void.
Side view of unit
mounted on the
wall in a cupboard in
upright position as
shown to comply
with safety regulations.
Condensate drain,
uninsulated drain
pipe with min 5ofall
running to a soil
vent pipe.
Valve in ceiling.
Extract air
from house
Intake air
from outside
Exhaust air
from house
to outside Supply air
to house
Unit weight is 30kg.
1.0 Introduction
The MRXBOX95B-450 WC and MRXBOX95B-450 wall mounted
units are designed to provide mechanical supply and extract
ventilation with heat recovery and summer bypass.
It also incorporates an integral humidistat and frost protection
(-5 degrees C as standard).
The unit is supplied with independent control for both supply and
extract for 3 speeds.
To recover heat from the extract air the heat exchanger block is
utilised. The heat exchanger can recover up to 95% of the normally
wasted heat.
Figure 1. Airflow through unit in standard configuration.
2.0 Installation
Installation must be carried out by competent personnel in
accordance with the appropriate authority and conforming
to all statutory governing regulations. All mains wiring must be in
accordance with the current I.E.E. Regulations, or the appropriate
standards. Ensure that the mains supply (Voltage, Frequency and
Phase) complies with the rating label.
Please note a clear working space is required around the installed unit
to allow the cover to be removed and provide sufficient access for
maintenance such as filter change.
Please allow a minimum of 600mm in front of the unit and 200mm
on the humidistat adjustment side. The (450 WC unit only) will also
require a minimum of 400mm above the unit for access to the
receiver in its standard position. Alternatively, the receiver may be
fitted away from the unit as it is wired with a flying lead.
The fan must be installed indoors, on a suitable wall away from direct
sources of frost, heat, water spray or moisture generation.
For a vibration-free result the unit must be mounted to a solid wall.
The unit is designed for wall mounting only on a solid wall, a gypsum
block or a stud wall will not suffice. Additional measures such as
extra studs or double panelling using 20mm MDF is required.
1. One part of the mounting bracket should be offered up to the
wall, ensuring it’s located horizontally. Mark the fixing points
through the pre drilled holes in the bracket and install with screws
(by others), ensuring the interlock side is at the top, (fig. 2).
2. Install the unit on the wall by ensuring the bracket on the unit
interlocks over the wall mounted bracket (fig. 3).
Note: Care must be taken to ensure the unit is installed true in
all 3 dimensions. Failure to do so may result in overflow from the
internal condensation drip tray.
Figure 2. Fixing the mounting bracket to the wall.
Figure 3. Mounting the unit on the wall mounted bracket.
Figure 4. Typical example of a cupboard mounted unit on a wall using
the bracket.
Nuaire: A Trading Division of Polypipe Limited Western Industrial Estate Caerphilly United Kingdom CF83 1NA
T: 029 2088 5911 F: 029 2088 7033 E: [email protected] W: www.nuaire.co.uk
1

Any air intake terminal MUST be installed in accordance
with the appropriate regulation. Installers are advised to be
aware of the requirements of this standard when installing
‘through the wall’ supply air ducting.
2.1 Condensate Drain
1. If using a U-trap please ensure the U-trap has been filled to a
suitable level of water to avoid any air locks.
2. If the condensation pipe is fitted in an unheated space the pipe
should be in insulated to prevent freezing.
Figure 5a. Wet option.
Condensate pipe connection
to unit and a typical example
of a “U” trap drainpipe.
2.2 Extract/input areas
The unit is designed to extract air from all wet rooms e.g. bathroom,
kitchen, en-suite, utility room (with sink) and WC’s.
Supply air should be to all habitable rooms e.g. bedrooms and lounge.
Extract / input grilles should be adjustable valve types (not supplied).
2.3 Ducting
It is recommended that rigid ducting be used it all times.
Flexible ducting has a very high resistance and it is impossible to
calculate how much resistance will be on a system if used.
If used, the flexible ducting must be kept to a minimum and should
always be pulled taut. A maximum of 300mm should be used on
each leg.
To prevent condensation on the exterior of the outside air inlet duct
and the air outlet duct from the unit, these ducts should be insulated
with material having a thermal resistance of >0.625m2/w.
Ducting must be installed in such a way that resistance to airflow is
minimised. Bends should be kept to a minimum.
A minimum distance of 200mm between the appliance and any bends
in ductwork is recommended. Ideally 200mm diameter or 204 x 60mm
rectangular ducting should be used.
Ducting joints must be sealed with silicone type sealant and shall be
adequately and reliably fixed to the appliance.
2.4 Ventilation flow rates
Flow rates applicable to local market. Meets EPBD
requirements / EN308 tested.
2.5 Handing
The unit may be handed to switch the supply and extract spigot
positions, this can be done by following the steps below and are
shown in fig. 6.
Note: This process should only be carried out by a competent and
qualified person.
Step 1. Remove the front cover and inner panel followed by the rear
panel to gain access to the inside of the unit
Step 2. Partially pull out the metal tray to access the circuit board
and cable connections. All connections are required to be
disconnected and although assistance has been given to allow correct
reconnection please familiarise yourself with the layout before doing
so. Once all connections are disconnected the PCB tray can then be
fully removed, at this point the cables should be pulled through to the
other side of the unit. Then slide the PCB tray partially into the unit
ensuring the stand offs are on the side the front cover is going to be
fixed and that no cables are trapped. All cables can then be
re-connected to the PCB as per the original arrangement, note the
following cables have been tagged with a cable tie approximately
25mm from its termination point for identification as there are two
identical components. These are supply control cables, supply power
cables, TH1 and SWL1.
Once complete the PCB tray can be slid in the remainder of the way.
Step 3. The filter should be reversed so the pull tab is at the side the
front cover is to be attached
Step 4. The panels and cover removed in step 1 can then be
re-assembled to the opposing sides that they were removed, care
should be taken to ensure a good seal is achieved.
Figure 6. Unit handing view.
Figure 7. Airflow through unit in handed configuration.
227. 11. 17. Leaflet number 671617
Installation and Maintenance MRXBOX95B-450 WC and MRXBOX95B-450
Figure 5b. MVHR-DRAIN option.
Condensate drain, uninsulated
drain pipe with min 5ofall running
to soil vent pipe.
Min 5o Drop
Collar
PCB
Front cover
Inner panel
Filter x 2
Rear panel
PCB tray
Exhaust air from
house to outside
Supply air
to house
Extract air
from house
Intake air
from outside

3.0 Performance
Sound Power Levels dB re 1pW
63 125 250 500 1 2 4 8 LwA
Extract Full speed Open inlet 58 56 57 63 57 51 46 45 63
90% Open Inlet 58 55 56 62 55 49 44 43 61
80% Open Inlet 57 55 55 60 53 47 42 41 59
65% Open Inlet 56 53 52 57 47 41 36 35 55
45% Open Inlet 54 50 49 52 40 34 29 28 50
30% Open Inlet 51 47 43 44 29 23 18 17 43
Intake Full Speed Open Inlet 56 54 59 67 55 48 37 34 64
90% Open Inlet 56 53 58 66 53 46 35 32 63
80% Open Inlet 55 53 57 64 51 44 33 30 61
65% Open Inlet 54 51 54 61 45 38 27 24 58
45% Open Inlet 52 48 51 56 38 31 20 17 53
30% Open Inlet 49 45 45 48 27 20 16 16 45
Discharge Full Speed Open Outlet 67 63 65 75 68 63 56 53 74
90% Open Outlet 67 62 64 74 66 61 54 51 73
80% Open Outlet 66 62 63 72 64 59 52 49 71
65% Open Outlet 65 60 60 69 58 53 46 43 67
45% Open Outlet 63 57 57 64 51 46 39 36 62
30% Open Outlet 60 54 51 56 40 35 28 25 54
Supply Full Speed Open Outlet 59 62 65 71 65 63 57 53 71
90% Open Outlet 59 61 64 70 63 61 55 51 70
80% Open Outlet 58 61 63 68 61 59 53 49 68
65% Open Outlet 57 59 60 65 55 53 47 43 64
45% Open Outlet 55 56 57 60 48 46 40 36 59
30% Open Outlet 52 53 51 52 37 35 29 25 51
Breakout Sound
Pressure Level
dBA@ 3m LwA
Breakout Full Speed Breakout 61 61 60 63 53 48 40 35 40 61
90% Breakout 61 60 59 62 51 46 38 33 39 60
80% Breakout 60 60 58 60 49 44 36 31 37 58
65% Breakout 59 58 55 57 43 38 30 25 34 55
45% Breakout 57 55 52 52 36 31 23 18 29 50
30% Breakout 54 52 46 44 25 20 16 16 22 43
3.1 Sound and Breakout Levels
327. 11. 17. Leaflet number 671617
Installation and Maintenance MRXBOX95B-450 WC and MRXBOX95B-450
0 100 200 300 400 500 600 700
800
700
600
500
400
300
200
100
0
Air volume flow rate (m3/hr)
Fan Static Pressure
100% Duty
90% Duty
80% Duty
65% Duty
45% Duty
30% Duty

4.0 Dimensions (mm) MRXBOX95B-450WC with wireless control Figure 8.
427. 11. 17. Leaflet number 671617
Installation and Maintenance MRXBOX95B-450 WC and MRXBOX95B-450
290 139
710
710 585
Mounting Bracket
View from top
Front view Side view
4 x Spigots
180mm Internal Diameter
200mm External Diameter
Condensate
drain B32mm
outside 18
Ecosmart connection grommets
Humidistat
adjustment
485
= =
4.1 Dimensions (mm) MRXBOX95B-450 Figure 9.
4.2 Dimensions for unit wall
mounting bracket position
on 450WC & 450 units
= =
200
176
534
67
492 CRS
67
40.0 CRS
5 Fixing
Points
Bracket to
be fitted to
the wall
40.0 CRS
86.0
Front view Side view
86.0
15.0
23.0
Flush mounting face to
wall or back box
View from back
86.0
Front view Side view
86.0 11.0
Figure 8a. Dimensions: 450WC unit switch.
Figure 9a. Dimensions: MRXBOX95-3SWITCH
4 x Spigots
180mm Internal Diameter
200mm External Diameter
290 139
485
710
710 585
View from top
Front view Side view
Wireless Control Box
790
18
Ecosmart connection grommets
Wireless Receiver
Humidistat
adjustment
Mounting Bracket
Condensate
drain B32mm
outside
= =

5.0 Electrical Connection
Please note: the electrical connection of the unit must be be carried
out by a qualified electrician.
The unit is supplied with a flexible cord for connection to the
mains supply.
NOTE: In the event of 1kV transients the fans may stop running,
normal operation will be resumed when the interference has ceased.
Electrical details:-
Voltage: 230V 1ph 50Hz
Consumption: 2.5 Amp
Fuse rating: 5 Amp
NOTE: This unit must be earthed.
The cable from the mains power supply should be connected to a
fixed wiring installation, via a fused isolator, in accordance with
current IEE wiring regulations.
Power at reduced speed:-
% Speed W
100 337
90 246
80 173
65 93
45 31
30 <20
NOTE: Wiring is for reference purposes only as the connections shown
are factory fitted. The unit is pre-wired with a 2 metre fly lead.
527. 11. 17. Leaflet number 671617
Installation and Maintenance MRXBOX95B-450 WC and MRXBOX95B-450
For good EMC engineering practice, any sensor cables
or switched live cables should not be
placed within 50mm of other cables or on the same
metal cable tray as other cables.
Figure 10. PCB board.
CN7 EXTRACT CN6 SUPPLY
BLU
WHI
YEL
RED
SUPPLY
BYPASS
SUPPLY FAN
EXTRACT FAN
B
L
U
B
R
N
B
R
N
B
L
U
EXTRACT FAN
B
L
U
B
R
N
EXTERNAL PUMP
BLU
WHI
YELI
RED
FAIL
CN8
TH1 TH2
Supply Extract Supply Extract Supply Extract
CN5
Supply cord
SPEED 1 SPEED 2 SPEED 3
Ecosmart connections
Humidistat
connections
Fuse 5A
MAINS
230V
50Hz N
L
MAINS
230V
50Hz N
L
2 Pole
Isolator
3 Position Switch Ancillary code:
MRXBOX95-3SWITCH
Blue
Brown
Supply cord
from unit
Green/yellow
Blue
Brown
Black
Supply cord
from unit
Grey
Green/yellow
L
1
2
Fuse 5A
MAINS
230V
50Hz N
L
3 Pole
Isolator
3 Position Switch Ancillary code:
MRXBOX95-3SWITCH
Green/yellow
Blue
Brown
Black
Supply cord
from unit
Grey
L1
2
Fuse 5A
2 Pole
Isolator
Room
light
Light
switch
(Double
Pole)
MAINS
230V
50Hz N
L
3 Pole
Isolator
3 Position Switch Ancillary code:
MRXBOX95-3SWITCH
Green/yellow
Blue
Brown
Black
Supply cord
from unit
Grey
L1
2
Fuse 5A Room
lights
Light
switches
(Double
Pole)
MRXBOX95B-450WC
Figure 11a.
MRXBOX95B-450
Figure 11b.
Disconnection from the supply mains must
be incorporated within the fixed wiring in
accordance with the wiring regulations and
shall have a minimum contact separation
of 3mm.
5.1 Examples of typical wiring layouts
MRXBOX95B-450
Figure 11c. Unit serving one bathroom.
MRXBOX95B-450
Figure 11d. Unit serving two bathrooms.
Disconnection from the supply mains must
be incorporated within the fixed wiring in
accordance with the wiring regulations and
shall have a minimum contact separation
of 3mm.
Disconnection from the supply mains must
be incorporated within the fixed wiring in
accordance with the wiring regulations and
shall have a minimum contact separation
of 3mm.
Disconnection from the supply mains must
be incorporated within the fixed wiring in
accordance with the wiring regulations and
shall have a minimum contact separation
of 3mm.

627. 11. 17. Leaflet number 671617
Installation and Maintenance MRXBOX95B-450 WC and MRXBOX95B-450
5.0 Wireless control
Note: This process should only be carried out by a competent and
qualified person.
The wireless control comes pre-set, if for any reason this needs to be
repeated e.g. a replacement switch required the following steps
should be followed. The unit needs to be powered to carry this out,
care should be taken of live electrics while carrying out the task.
Step 1. Remove the cover from the wireless receiver on top of the
unit using a terminal screwdriver.
Step 2. Press and hold push button M4 so that the buzzer sounds
continually, while it sounds press one of the buttons on the
switch that is to be paired. Repeat this process for any
additional switches that are to be paired.
Step 3. The system should now be fully functional and the cover
can be re-fitted.
The duration of the timed boost may be adjusted between
5 - 30 mins using the trimmer as shown in fig 13. below.
A diagram of the wireless receiver is shown below, this is for reference
only as the unit comes pre-wired.
Figure 13. Wireless receiver.
5.2 Ecosmart controls
A maximum of two Ecosmart sensors can be connected directly to the
main circuit board, this can be done by cutting a small slit in the
20mm grommets situated on the top of the unit, the cable can then
be threaded through to gain access to the connections on the PCB. If
more than 2 connections are required an Ecosmart junction box will
be required.
When a sensor is activated the unit will switch to speed 3 and run-on
for 15 minutes after the signal is lost. Some sensors may also have
additional optional run-on features.
M1
Antenna input
(wire 8.5cm)
FUSE 10A L2 FUSE 10A L3
FUSE 10A L4
M4MT
5.1 Switches
The wireless switch is supplied with a battery but this is not fitted, to
fit the battery pull out the carrier at the base of the switch and insert
the battery with the text facing you.
To fix either switch to a wall or back box remove the front fascia by
inserting a terminal screwdriver into the two openings along the
bottom edge and prize open gently. The fixing points on the back
plate can then be accessed, once the switch has been secured the
front fascia can then be re-fitted.
Note: The wireless switch will typically operate up to a distance of
30m inside a building, however, this is dependent on the layout and
construction of the building. This distance will be reduced
depending on obstructions e.g. walls. If the switch will not operate
an additional wire aerial is supplied attached to the outside of the
receiver cover, if required this can be fitted under the dome nut of
the receiver and should point vertically skywards.
The filters fitted inside the unit are protected with a
plastic film. Prior to commissioning remove the covers (fig 13), take off
the film and replace.
6.0 Commissioning
1. The unit should be run for a minimum of 10 minutes to reach
steady state before commencing commissioning.
2. The humidity sensor is initially set to its least sensitive position, this
should be adjusted during commissioning. Depending on storage
and site conditions the unit may boost due to high relative
humidity levels, this will continue until the level drops below the
specified set point.
3. The unit is supplied with independent control for both normal and
boost airflows. (see fig. 14).
4. Correct commissioning is essential to ensure the ventilation air
flow rates are met. It also ensures the unit is not over ventilating
and causing excessive power consumption.
5. Adjustment valves should be locked in place to prevent further
adjustment.
6. Once commissioned the home owner / tenant should be informed
that the unit should not be adjusted as it will have a detrimental
effect on the indoor air quality and could result in condensation
and mould growth. The label covering the control has an adhesive
panel which should be removed post commissioning to prevent
tampering.
Figure 14. Detail of unit control on front panel.
+ - ++ -- + - + -
Post commissioning remove
adhesive backing under
this section
Power
060905
For commissioning:
refer to user manual
Ventilation Controls
+ -

Isolation - Before commencing work make sure that the
unit, switched live and Nuaire control are electrically
isolated from the mains supply and switched live supply.
6.1 Humidity adjustment
This product contains an internal humidity sensor fitted into the
airflow extracting from the wet rooms. When the unit senses that the
humidity exceeds the set point the unit will boost to that set by the
commissioned boost speed. The set point can be found on the side of
the unit (see fig 8) and is at its most sensitive when turned fully
clockwise. Note that the sensor is measuring humidity from all the
wet rooms at the same time and should not be relied on to solely
boost the unit.
Additional switch should be used local to the wet rooms (see wiring
diagrams).
7.0 Maintenance/Cleaning
We recommend that the two G4 filters are inspected and cleaned
after 6 months and replaced every 12 months. This will be indicated
by the first LED from the right hand side flashing, the LED will flash
for a two week period and then reset itself.
The filters can be removed from the unit by removing the two filter
covers on the front panel of the unit. Take hold of the two circular
tabs either end of the filter covers and pull out.
The filter can now be extracted by pulling the removal loop on the
front edge of the filter. Once the filters have been inspected return
or replace them as necessary.
Inspect the heat exchanger every 5 years. Generally check for damage
and security of components. The heat exchanger should be fitted in
the same orientation as originally assembled e.g. front label facing
removable cover and top label nearest PCB.
Figure 15. Removing the two filter covers on the front panel
of the unit.
Figure 16. The filters can be removed by pulling on the black tab on the
visible end of the filters.
Telephone [phone]
727. 11. 17. Leaflet number 671617
Installation and Maintenance MRXBOX95B-450 WC and MRXBOX95B-450
Filter covers
Filter being
removed
Filter cover
8.0 Replacement of Parts
Should any component need replacing Nuaire keep extensive
stocks for quick delivery. Ensure that the unit is electrically
isolated, before carrying out any work.
Note: The supply cable must be replaced by an electrically
competent person.
When ordering spare parts, please quote the serial number
of the unit and the ARC number of the purchase if possible.
(This information will be available on the fan label).
9.0 Warranty
MRXBOX95B-450 WC and MRXBOX95B-450 have a 1 year
warranty.
This warranty is void if the equipment is modified without
authorisation, is incorrectly applied, misused, disassembled, or
not installed, commissioned and maintained in accordance with
the details contained in this manual and general good practice.
The product warranty applies to the UK mainland and in
accordance with Clause 14 of our Conditions of Sale. Customers
purchasing from outside of the UK should contact Nuaire
International Sales office for further details.
10.0 After Sales Enquiries
For technical assistance or further product information, please
contact the After Sales Department.