Vent-Axia NBR HTP 473809 Assembly instructions

CONTINUOUSLY RUNNING FAN
Installation and Wiring Instructions
Stock Ref. N°
NBR HTP 473809
PLEASE READ INSTRUCTIONS IN CONJUNCTION WITH ILLUSTRATIONS.
PLEASE SAVE THESE INSTRUCTIONS.
NBR
IPX4
220-240V~50Hz

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Installation and Wiring Instructions for the NBR Extractor Fan.
IMPORTANT:
READ THESE INSTRUCTIONS
BEFORE COMMENCING THE
INSTALLATION
DO NOT install this product in areas where the following may be present or occur:
•Excessive oil or a grease laden atmosphere.
•Corrosive or flammable gases, liquids or vapours.
• Ambient temperatures higher than 40°C or less than –5°C.
• Possible obstructions which would hinder the access or removal of the Fan.
SAFETY AND GUIDANCE NOTES
A. All wiring to be in accordance with the current I.E.E. Regulations, or the appropriate
standards of your country and MUST be installed by a suitably qualified person.
B. The Fan should be provided with a local isolator switch capable of disconnecting all poles,
having a contact separation of at least 3mm.
C. Ensure that the mains supply (Voltage, Frequency, and Phase) complies with the rating
label.
D. The Fan should only be used in conjunction with the appropriate Vent-Axia products.
E. The fan should only be used in conjunction with fixed wiring.
F. When the Fan is used to remove air from a room containing a fuel-burning appliance,
ensure that the air replacement is adequate for both the fan and the fuel-burning appliance.
G. The Fan should not be used where it is liable to be subject to direct water spray for
prolonged periods of time.
H. Where ducted Fans are used to handle moisture-laden air, a condensation trap should be
fitted. Horizontal ducts should be arranged to slope slightly downwards away from the Fan.
I. 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 use of the appliance by a person responsible for
their safety.
J. Young children should be supervised to ensure that they do not play with the appliance.
DESCRIPTION
The NBR fan is a continuously running extract fan for kitchens, utility rooms, bathrooms
and toilets.
The product incorporates an airflow detection system that detects the installation duct
resistance and maintains the correct fan speed to achieve the preset extract flow rate of
either 6l/s, 8l/s or 13l/s, minimising energy use and noise (see Section C-Setup for more
information).
The incorporated LED display allows the installer to verify the installed flow rate, and
also provides feedback for system pressure.
The fan can be wall or panel/ceiling mounted.
ACCESSORIES (not supplied)
WALL FITTING KIT
A range of white (stock ref. 254102) or brown (stock ref. 254100) 100mm wall kits are
available for installing into most walls using telescopic liners supplied.

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A. INSTALLATION
PANEL/CEILING MOUNTING
1. Cut a 105mm diameter hole.
2. Remove the front panel by carefully pulling away from the fan.
3. Loosen the two self-retaining screws and remove the inner grille by carefully
pulling away from the housing.
4. Mark the screw centres through the holes in the fan back plate. Drill, plug and
screw into position. Attach ducting as required for the installation.
5. Wire the fan as described in Section B-Wiring. Adjust any settings as required
(see Section C-Setup).
6. After installation, ensure impeller rotates freely.
7. Replace the inner grille and tighten the retaining screws. Replace the front panel.
WALL MOUNTING
1. For wall mounting cut a 117mm diameter hole through the wall and insert the wall
sleeve. Slope the sleeve slightly downwards away from the fan. Where necessary
cut to length and cement both ends into position flush with the wall faces.
2. Fix exterior grille into position with the louvres positioned downwards.
3. Remove the front panel by carefully pulling away from the fan.
4. Loosen the two self-retaining screws and remove the inner grille by carefully
pulling away from the housing.
5. Mark the screw centres through the holes in the fan back plate. Drill, plug and
screw into position.
6. Wire the fan as described in Section B-Wiring. Adjust any settings as required
(see Section C-Setup).
7. After installation, ensure impeller rotates freely.
8. Replace the inner grille and tighten the retaining screws. Replace the front panel.
B. WIRING.
WARNING: THE FAN AND ANCILLARY CONTROL EQUIPMENT MUST BE
ISOLATED FROM THE POWER SUPPLY DURING THE INSTALLATION /
OR MAINTENANCE.
IMPORTANT
The cross - sectional area of supply cord used should be ranged from 1 -1.5mm2.
The extraction fan is suitable for connection to 220-240V 50Hz supply.
The fan is a class ll double insulated product and MUST NOT be earthed.
1. Select and follow the appropriate wiring diagram. (Fig. 1, 2 or 3)
2. Check all connections have been made correctly and ensure all terminal
connections and supply wires are securely fastened.
3. Ensure the impeller rotates and is free from obstructions.

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C. SETUP
WARNING: THE FAN AND ANCILLARY CONTROL EQUIPMENT MUST BE
ISOLATED FROM THE POWER SUPPLY DURING THE INSTALLATION /
OR MAINTENANCE.
1) Trickle speed selection (6l/s or 8l/s) – (Fig. 5)
In normal running mode the fan can extract at either 6l/s (22m3/h) or 8l/s (29m3/h)
flow rate. The fan will boost to 13l/s (46.8m3/h) when the LS connection is switched or
humidity rises above the set point (see humidity setting below).
Factory set at 6l/s (22m3/h).
Remove jumper connector (JP1) if 8l/s (29m3/h) extract flow rate is
required.
2) Airflow detection system – enable/disable (Fig. 5)
The airflow detection system will detect the installation duct resistance and also react
to external wind conditions to ensure the fan maintains a constant extraction rate.
This can cause the fan to ramp up and down and in most applications will not be
required. To turn this feature on, complete the following:
Push dip switch 1 (SW1) into the on position to turn on constant flow mode.
Push dip switch 1 (SW1) into the off position to turn off constant flow mode.
(Factory set)
IMPORTANT – On first power up, the fan will run through its initialisation routine. For
the first 15 minutes, the flow rate and pressure will be displayed. The fan may not be
fully functional until this is over. After the first 15 minutes, the fan will calibrate the
installation which will involve the fan speeding up and down for a few minutes. Once
this is complete the fan will operate normally with the display off.
3) LED Display with prism (Fig. 6)
For the first 15 minutes EVERY time the fan is powered off and on (via the isolator),
the display will cycle between displaying the actual airflow rate (l/s) being achieved*
and system pressure (Pa). They will cycle every 10-20 seconds, where the pressure
will flash, and the airflow rate will be on constantly.
*Airflow detection system must be enabled to display the calibrated flow rate.
4) Fixed timer
The HTP model incorporates an optional fixed timer – set at 15 minutes. This is
the time the fan will continue to run on boost after the LS connection has been
deactivated. The integral pullcord timer is fixed at 15 minutes and cannot be
disabled.
To ENABLE the fixed overrun timer, link JP2 as shown in fig. 5.
To DISABLE the fixed overrun timer, remove the link in fig. 5.

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5) Adjustable ambient Response humidistat
The HTP model incorporates an adjustable ambient response humidistat. The fan
will increases the extract rate if the humidity rises above the set point – adjustable
via the pot shown in fig. 5.
To RAISE the set-point use a small screwdriver to turn the adjuster Fig.5.
ANTICLOCKWISE. This makes the controller LESS sensitive.
To LOWER the set-point use a small screwdriver to turn the adjuster Fig.5.
CLOCKWISE. This makes the controller MORE sensitive.
To switch the humidistat off, turn the adjuster pot fully clockwise. The fan will
only switch on via the humidistat if the ambient humidity rises above 90%RH.
Note: The ambient Response feature will automatically boost the fan to 13l/s if
the humidity rises quickly irrespective of the set point and run on for the pre-
determined timeout period.
6) Pullcord
The integral pullcord activates the timer (see 4 and 5 above) and the fan will run at
13l/s for the set time period. If the integral pullcord is pulled for a second time
(once activated), the timer will be cancelled and the fan will revert back to the
trickle extract rate.
To remove the pullcord, cut the cord and leave the switch in place. There is no
need to switch the fan on/off beforehand.
7) System pressure detection
The fan can detect the system pressure for fault finding. If the fan seems noisy or
cannot achieve the desired flow rate, this could be due to a blocked duct or the
ducting has not been suitably stretched during installation (if flexible ducting is
used). This is displayed during the first 15 minutes EVERY time the fan is
powered off and on (via the isolator). The number is displayed in Pascals (Pa) and
the higher the number, the more torturous the system (and air path) – i.e. harder
for the fan to move the air through the ducting. As a consequence the fan has to
use more energy and it will increase the fans noise level.
The fan will maintain the correct airflow rate up to a maximum of 30Pa system
pressure. The system pressure will be different for all speeds, but worst on the
13l/s setting.
8) Fan silent running boost mode: This feature delays the boost operation for a
maximum of 20 minutes to reduce noise and cold drafts while bathing. After LS is
disconnected, the fan will look at the amount of time since the LS was activated
and then run the fan on boost for that same period or to a maximum of 20
minutes, whichever is shorter.
a. Dip switch 2 in the off position – Traditional mode (factory set) (fig. 5):
i. Standard running - with LS off, pullcord off. Fan continues to run on
the set trickle speed - 6 or 8l/s.
ii. When the integral pullcord is activated, the fan will run at 13l/s (boost)
for a timed period.(Timer is fixed to 15 minutes).

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iii. When the LS is connected, the fan will run at 13l/s until deactivated
(plus overrun timed period where applicable).
b. Dip switch 2 in the on position:
i. Standard running – with the LS off, pullcord off. Fan continues to run
on the set trickle speed - 6 or 8l/s.
ii. When the integral pullcord is activated, the fan will boost as per
“Traditional Mode” above.
iii. When the LS is activated, the fan will remain in trickle mode until the
LS is disconnected for a maximum of 20 minutes.
iv. After this 20 minute period or when the LS is disconnected
(whichever happens first), the fan will change to 13l/s (boost mode)
and continue to run on boost for the same period as between the LS
activation and deactivation, up to a maximum of 20 minutes.
v. However, if the LS is deactivated within 3 minutes of activation, then
the fan continues in trickle mode and does not boost.
9) Calibration
The airflow sensor is calibrated at the factory using UKAS accredited
equipment. Details of the equipment and certification can be found on the
inside of the fan.
D. SERVICING AND MAINTENANCE.
WARNING: THE FAN AND ANCILLARY CONTROL EQUIPMENT MUST BE
ISOLATED FROM THE POWER SUPPLY DURING MAINTENANCE.
1. At intervals appropriate to the installation, the fan should be inspected and cleaned to
ensure there is no build up of dirt or other deposits.
2. Carefully pull the front panel off the inner grille. (fig. 4)
3. Wipe the inlets and front face with a damp cloth until clean. Be careful not to push
dirt into the airflow sensor.
The fan has sealed for life bearings, which do not require lubrication.
E. TROUBLESHOOTING
1. Fan continuously speeds up and down:
a. Cause:
i. This usually means the fan cannot stabilise at the desired airflow rate.
ii. This could be due to the ducting being blocked, or being very windy.
b. Solution:
i. If this persists after the ducting has been checked or the property is
very exposed to high winds, it is recommended to turn the airflow
detection system off. (Section C2)
2. The fan continuously runs in boost (HTP model only):
a. Cause:
i. The room is damp or recently redecorated.

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ii. The humidity set point is set too low.
b. Solution:
i. If the room is damp or has recently been decorated, it could take up
to 2 weeks for the humidity levels to stabilise. Please leave the fan to
dry out the room and after this period the fan should run normally.
ii. The humidity set point could be set too low. Adjust the humidity set
point to a higher setting. (Section C6)
3. The fan does not turn to boost when the humidity is high:
a. Cause:
i. The humidity set point is set too high.
b. Solution:
i. Adjust the humidity set point to a lower setting. (Section C6)
4. Water is dripping out of the fan when installed in a ceiling:
a. Cause:
i. This is caused by condensation forming on the inside of the ducting
and dripping out of the fan inlet.
b. Solution:
i. This is normal and the fan is designed to handle condensation build
up. However a condensation trap connected immediately after the fan
will help to prevent water dripping into the room.

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Fig.2 Continuous boost (13l/s) with no trickle facility. (The fan is internally fused)
Fig.3 Continuous trickle with boost facility. (The fan is internally fused)
Fig.1 Continuous trickle (6l/s or 8l/s) with no boost facility. (The fan is internally fused)
Siting
the
fan.
 

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Fig.4. Removing the grille for wiring and setting the controls
Pull front panel as shown. Loosen screws – DO NOT REMOVE FROM GRILLE
(the screws are self-retaining)
Pull inner grille away from housing as shown. When replacing grille, ensure the flow sensor is
aligned with the corresponding slot in the grille.
Fig.5. Controls
Note:- Before changing any of the dipswitch positions the fan
must be isolated from the power supply.
Trickle speed (JP1) (All models)
8l/s = Remove Jumper Connector
6l/s = Replace Jumper Connector (factory set)
(For 13l/s, permanently link terminal connections L to LS)
Airflow detection system (All models)
Auto sensing mode = Dip switch 1 (SW1) into the
on position to turn on airflow detection system.
Manual mode = Dip switch 1 (SW1) into the off
position to turn off airflow detection system
Silent running boost mode (TP & HTP only)
Off = Dip switch 2 (SW1) in the off position
Traditional mode (factory set)
On = Dip switch 2 (SW1) in the on position
This feature will delay the boost operation
for a maximum of 20 minutes.
(see C.SETUP section Item 9)
1
2
O
N
1
2
O
N
12
ON
12
ON
JP1 - Trickle
speed
SW1 – Airflow
detection system
and Silent running
boost
JP2 - Fixed
timer
enable/
disable
jumper
Adjuster for
humidistat
(HTP)

Fig. 6. Display and prism
The display can only be seen from the side. This is to allow the installer to view the display with the cover
attached as this can affect the airflow through the sensor.
Every 10-20 seconds the display will switch between displaying airflow rate and system pressure. The system
pressure will flash.
Airflow will be displayed like this: 13.2 (13.2l/s flow rate)
Pressure will be displayed like this: 17 (flashing – 17Pa system pressure)