Units should always be positioned with sufficient space
to allow removal of the access covers and subsequent
removal of fan and motor assemblies etc.
The installation must be carried out by competent
personnel in accordance with the appropriate authority and
conforming to all statutory and governing regulations.
2
Unit Code
Prefab Code
A
B
C
D
E
F
G
NALTF 9-10
NALPFC 4B
767
767
947
947
837
837
75
NALTF 11-12
NALPFC 5B
973
973
1203
1203
1064
1064
100
NALTF 13-17
NALPFC 6B
1169
1375
1399
1605
1268
1471
100
Unit
Prefab
Code
Curb Code
A
B
C
NALTF 9-10
NALPFC 4B
917
917
250
NALTF 11-12
NALPFC 5B
1173
1173
250
NALTF 13-17
NALPFC 6B
1374
1580
250
NALTF/TRF
Roof and Plantroom Twinfans
15. 05. 17. Leaflet Number 671269
Roof Opening Dimensions
Figure 6.
Figure 5.
Note: Prefabricated curbs can be used to support internal or external units.
Typical Roof Upstand for NALTF 18-24
Figure 7.
680 700 Spigot
640
50mm Spigot
1
2030
1183
1550 min
Curb
1850 max
165 louvre
1200 Spigot
2313
700 Spigot
210
1200 Spigot
2140 max
150
Curb
3.0 Installation
Units must not be installed at an angle over 5
o
from the
horizontal (to ensure the backdraught shutters operate
satisfactorily). Units must be installed with the access panel
on top, never up-side-down.
Ductwork connections must be airtight to prevent loss of
performance.
The method of mounting used is the total responsibility of
the installer. The lower edge of the casing has an internal
skirt allowing the unit to be located on an upstand or
prefabricated curb if desired. The units must be securely
screw fixed to the upstand/curb to prevent vibration and/or
wind damage.
It is the installers responsibility to drill the case to provide
access for the electrical cables. Care should be taken not to
damage internal components and the cable entry must be
properly sealed. NOTE: on bottom inlet units the electrical
cabling may be routed up through the bottom inlet spigot.
Upstand Details
Details of roof opening dimensions etc required and basic
construction of a builders upstand etc are shown below for
typical concrete and decking roof installations.
Testing after Installation
Ensure that the Fan unit and any specified controls are
fitted securely according to the instructions.
Switch on the mains supply. Push the test button to run
each fan and check that they run satisfactorily.
If a switched live signal is used, activate this signal and
check that the fan runs. De-activate the switched live signal
and check the run-on-time; adjust if necessary.
Adjust the maximum and minimum airflow (if required) by
following the commissioning procedures.
Prefabricated Curb
CODES: NALPFC (typical)
Manufactured in
aluminium alloy these
curbs will reduce design
work and guarantee correct
unit mounting when on site.
Note: Upper faces of curb are fitted with robust sealing
strip.
Prefabricated curb dimensions
