Belimo AFB24-MFT - General Wiring Instructions; Transformer Sizing and Wire Lengths; Multiple Actuator Wiring; Initialization of -SR and -MFT Actuators

800-543-9038 USA 866-805-7089 CANADA 203-791-8396 LATIN AMERICA / CARIBBEAN
7
7
WARNING The wiring technician must be trained and experienced with electronic
circuits. Disconnect power supply before attempting any wiring connections or
changes. Make all connections in accordance with wiring diagrams and follow all
applicable local and national codes. Provide disconnect and overload protection as
required. Use copper, twisted pair, conductors only. If using electrical conduit, the
attachment to the actuator must be made with flexible conduit.
A
lwa
y
s read the controller manufacturer's installation literature carefull
y
b
efore makin
g
any connections
.
Follow all instructions in this literature. If you
h
ave an
y
q
uestions, contact the controller manufacturer and/or Belimo.
Transformers
The AFB24, AFX24…actuators require a 24 VA
C
class 2 transformer and draws a
maximum of 10 VA per actuator. The actuator enclosure cannot be opened in the
f
ield, there are no parts or components to be replaced or repaired
.
– EMC directive: 2004/108/EC
– Software class A: Mode of operation type 1
– Low voltage directive: 2006/95/EC
CAUTION: It is good practice to power electronic or digital controllers from a
separate power transformer than that used for actuators or other end devices. The
power supply design in our actuators and other end devices use half wave
rectification. Some controllers use full wave rectification. When these two different
types of power supplies are connected to the same power transformer and the DC
commons are connected together, a short circuit is created across one of the diodes
in the full wave power supply, damaging the controller. Only use a single power
transformer to power the controller and actuator if you know the controller power
supply uses half wave rectification.
Multiple Actuators, One Transformer
M
ultiple actuators may be powered from one transformer provided the followin
g
rules
a
re followed
:
1. The TOTAL current draw of the actuators
(
VA ratin
g)
is less than or equal to the
r
ating of the transformer.
2. Polarit
y
on the secondar
y
of the transformer is strictl
y
followed.
Thi
s means t
h
a
t
a
ll No. 1 wires
f
rom all actuators are connected to the common le
g
on th
e
t
rans
f
ormer and all No. 2 wires
f
rom all actuators are connected to the hotle
g
.
Mixing wire No. 1 & 2 on one leg of the transformer will result in erratic operation
or failure of the actuator and/or controls.
Multiple Actuators, Multiple Transformers
M
ultiple actuators positioned by the same control si
g
nal may be powered
f
rom
multiple trans
f
ormers provided the
f
ollowin
g
rules are
f
ollowed
:
1. The trans
f
ormers are
p
ro
p
erl
y
sized.
2. All No. 1 wires
f
rom all actuators are tied together and tied to the negative leg o
f
the control signal.
S
ee wiring diagram
.
Wire Length for AFB..., AFX... Actuators
Keep power wire runs below the len
g
ths listed in the F
ig
ure H. I
f
m
o
r
e
th
a
n
o
n
e
actuator is powered
f
rom the same wire run, divide the allowable wire length by the
n
umber of actuators to determine the maximum run to any single actuator.
Example: 3 actuators, 16 Ga wire
350 Ft ÷ 3 Actuators = 117 Ft. Maximum wire ru
n
M
AXIMUM WIRE LENGTH FOR 10V
A
W
ir
e
S
iz
e
M
a
x. F
ee
t. Wir
e
S
iz
e
M
a
x. F
ee
t
1
2 Ga 900 Ft.
1
8 Ga 220 Ft
.
1
4
Ga
550
Ft. 2
0
Ga
12
0
Ft.
1
6
G
a 350 Ft. 22
G
a 60 Ft
.
FIGURE
H
Wire Type and Wire Installation Tips
For most installations
,
18 or 16
G
a. cable works well with the AFB24
,
AFX24...
actuators. Use code-approved wire nuts, terminal strips or solderless connectors
where wires are joined. It is good practice to run control wires unspliced
f
rom the
actuator to the controller. I
f
splices are unavoidable, make sure the splice can be
r
eached for
p
ossible maintenance. Ta
p
e and
/
or wire-tie the s
p
lice to reduce the
p
ossibility o
f
the splice bein
g
inadvertently pulled apart.
The AFB24, AFX24... proportional actuators have a di
g
ital circuit that is desi
g
ned to
i
gnore most unwante
d
i
nput s
i
gna
l
s
(
p
i
c
k
up
)
.
I
n some s
i
tuat
i
ons t
h
e p
i
c
k
up may
b
e
severe enou
g
h to cause erratic runnin
g
of the actuator. For example, a lar
g
e
inductive load
(
hi
g
h volta
g
e AC wires, motors, etc.
)
runnin
g
near the power or
control wirin
g
may cause excessive pickup. To solve this problem, make one or
more o
f
the
f
ollowin
g
chan
g
es:
1. R
u
n th
e
wir
e
in m
e
t
a
lli
c
co
n
du
it
.
2
. Re-route the wirin
g
away from the source of pickup
.
3. Use shielded wire
(
Belden 8760 or equal
)
. Ground the shield to an earth ground.
Do not connect it to the actuator common.
Initialization of the -SR and -MFT
When
p
ower is initiall
y
a
pp
lied, the actuator will
f
irst release its manual
p
reload
p
osition (This assumes a manual position has been set). The actuator will then rotate
to the full fail-safe position. At this point the microprocessor reco
g
nizes that the
actuator is at full fail-safe and uses this
p
osition as the base for all of its
p
osition
calculations. The microprocessor will retain the initialized zero durin
g
short power
failures of u
p
to 20 seconds. The -
S
R and -MFT will also return to its
p
osition
p
rior to
the 20-second-or-less power loss. For power failures
g
reater than 20 seconds, the
actuator would naturall
y
return to its full fail-safe
p
osition
p
rior to the micro
p
rocessor
losin
g
its memory. The actuator will also re-initialize if the manual position
m
echa
n
is
m
is
used
.
I
nstallation Instruction
s
G
eneral Wirin
g
Instruction
s
N40103 - 09/11 - Subject to change. © Belimo Aircontrols (USA), Inc
.