Selection Guide

800-543-9038 USA 866-805-7089 CANADA 203-791-8396 LATIN AMERICA
85
In
s
t
a
ll
a
ti
o
n In
s
tr
uc
ti
o
n
s
Mechan
i
cal Installat
ion
Determining Torque Loading and Actuator Sizing
D
amper torque
l
oa
di
ngs, use
d
i
n se
l
ect
i
ng t
h
e correct s
i
ze actuator, s
h
ou
ld
b
e
provided by the damper manu
f
acturer. I
f
this in
f
ormation is not available, the
f
ollowing general selection guidelines can be used.
Dam
p
er T
ype
Torque Loadin
g
Opposed blade, without edge seals,
for non-tight close-off applications
3 in-lb/sq. ft
.
P
ara
ll
e
l
bl
a
d
e, w
i
t
h
out e
d
ge sea
l
s
,
for non-tight close-off applications
4
in-lb
/
sq. ft
.
Opposed blade, with edge seals
,
for tight close-off application
s
5
in-lb
/
sq. ft
.
Parallel blade, with edge seals,
for tight close-off application
s
7 in-lb/s
q
. ft
.
The above torque loadings will work for most applications with 1000 FPM face
velocity. For applications between this criteria and 2500 FPM, the torque loadin
g
s
hould be increased by a multiplier of 1.5. If the application calls for hi
g
her criteria
u
p
to 3000 FPM, use a multi
p
lier o
f
2.0
.
Torque Loading Chart
General Information
Belimo actuators should be mounted indoors in a dry, relatively clean environment
f
ree
f
rom corrosive
f
umes. I
f
the actuator is to be mounted outdoors, a protective
e
nclosure must be used to shield the actuator.
F
or new construct
i
on wor
k
,
o
rder dampers with extended sha
f
ts.
I
nstruct t
h
e
i
nstalling contractor to allow space
f
or mounting and service o
f
the Belimo actuator on
the shaft. The dam
p
er shaft must extend at least 3 1
/
2” from the duct. If the shaft
e
xtends less than 3-1
/
2” or if an obstruction blocks access, the shaft can be extended
with the AV 8-25 sha
f
t extension accessor
y
or the actuator ma
y
be mounted in its short
s
ha
f
t con
f
i
g
uration
.
Mechanical Operation
T
he actuator is mounted directly to a damper sha
f
t up to 1.05” in diameter by
means o
f
its universal clamp. A crank arm and several mounting brackets are
a
vailable
f
or applications where the actuator cannot be direct coupled to the damper
s
haft. The NFB, NFX series actuators provide true spring return operation for reliable
f
ail-sa
f
e application and positive close-o
ff
on air tight dampers. The spring return
sy
stem
p
rovides constant tor
q
ue to the dam
p
er with, and without,
p
ower a
pp
lied to
the actuator. The NFB…-S, NFX…-S versions are provided with two built-in
a
uxiliary switches. These SPDT switches are provided for safety interfacin
g
or
s
ignaling, for example, for fan start-up. The switching function at the fail-safe
p
osition is fixed at +10°, the other switch function is adjustable between +10° to
+90
°.
Automatic Airtight Dampers/Manual Override
T
he NFB, NFX series provides 95° of rotation and is provided with a
g
raduated
p
osition indicator showing 0° to 95°.
T
he NFB, NFX has a unique built in manual positioning mechanism which allows the
s
ettin
g
of any damper position within its 95° of rotation. A pre-tensioned sprin
g
a
utomatically ti
g
htens the damper when power is applied to the actuator,
c
ompensatin
g
f
or damper seal deterioration..
T
he actuator is shipped at +5° (5°
f
rom
f
ull
f
ail-sa
f
e) to provide automatic
c
ompression against damper gaskets
f
or tight shut-o
ff
. When power is applied, the
manual mechanism is released and the actuator drives toward the full fail-safe
p
osition.
Standard Mounting
N
O
TE: The NFB, NFX…ser
i
es actuator
i
s sh
i
pped w
i
th the manual overr
i
de
a
djusted for a +5° position at the universal clamp
(
not at full fail-safe, 0°
)
.
T
his allows
f
or automatic compression o
f
damper blade seals when the
a
ctuator is in use, providin
g
ti
g
ht shut-off. This assumes that the damper is to
h
ave ti
g
ht shut-o
ff
at the
f
ail-sa
f
e position. I
f
ti
g
ht close-o
ff
is desired at the
o
pposite direction
f
rom
f
ail-sa
f
e, the manual override should be released so
t
he actuator can
g
o to the full fail-safe position. See the manual override
i
nstruct
io
ns
.
1
. Manually move the damper to the
f
ail-sa
f
e position
(
usually closed
)
. I
f
the sha
f
t
rotated counterclockwise (
), this is a CCW installation. If the shaft rotated
)
clockwise (
), this is a CW installation. In a CCW installation, the actuator side
)
marked “CCW” faces out
,
while in a CW installation
,
the side marked “CW” faces
o
ut.
All
ot
h
er steps are
id
ent
i
ca
l
.
2
. The actuator is usually shipped with the universal clamp mounted to the “
CC
W”
s
ide o
f
the actuator. To test
f
or adequate sha
f
t length, slide the actuator over the
s
haft with the side marked “
CC
W” (or the “
C
W” side if this is the side with the
clamp). If the shaft extends at least 1
/
8” through the clamp, mount the actuator
a
s
f
ollows. I
f
not, go to the
Short Shaft Installation
section.
n
3
. If the clamp is not on the correct side as determined in step #1, re-mount the
clam
p
as
f
ollows. I
f
it is on the correct side,
p
roceed to ste
p
#5. Look at the
Torque Loading Chart
0
5
10
15
20
25
30
35
40
45
50
2345678910
Torque Loading (in-lb/ sq. ft.)
Damper Area (sq. ft.)
M40024 - 05/10 - Subject to change. © Belimo Aircontrols (USA), Inc.