AJAX PVG WW, Operating And Maintenance Manual

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MXG461…U, MXF461…U Series
Technical Instructions
Document No. CA1N4455E-P25
June 14, 2006
Modulating Control Valves with Magnetic Actuators
Sval0016R1
Sval0015R1
MXG461…U
MXF461…
U
Description
Mixing or stra
ight-throug
h valves with ma
gnetic a
c
tuat
ors fo
r modul
ating co
ntrol
of hot
and chilled water sy
stems
in clo
sed
circuits.
Features
x x x x x x x x x
Fast po
sitioni
ng time (on
e se
con
d), high
-re
sol
ution stroke (1:100
0).
Linea
r or e
qu
al-pe
rcenta
ge
valve
chara
cteristic
(u
ser-defined
).
Switch-selectable control
signal: 0 to 10 Vdc, 2 to 10 Vdc, or 4 to 20 mA.
Wea
r-f
ree ind
uctive stroke
measurement
.
Heavy-duty,
no maintenance requi
red.
Fail-safe feat
ure: A
ĺ
AB
clo
sed
whe
n de-e
ne
rgi
zed.
Positioning control. Position feedback. Manual cont
rol.
Product Numbers
See Table 1.
Warning/Caution Notations
W
ARN
IN
G:
Personal injur
y or loss of life may
occ
ur if
you do not
follo
w
the proc
edur
es as spec
ified.
CAUTIO
N:
Equi
pment damage or l
o
ss of data may
occ
ur if
y
o
u
do not follo
w
the procedur
es as specified.
Siemens Buil
di
ng T
e
chnol
ogi
es, Inc.
T
e
chnical Instructions
MXG4
61…U,
MX
F461…U M
odulating Control Valv
es
Docum
ent Number CA1N4455E-P25
w
it
h
Magnetic
Actuators
June 14, 2006 Page 2
Siemens Buil
di
ng T
e
chnol
ogi
es, Inc.
Application
The MXG461...U (screwed fitting) and MXF461
...U (fl
ange fitting) valves are mixing or
straig
ht-throu
gh valves wit
h a factory ca
librated and
mounted m
a
gnetic actuator. The
magneti
c act
uator in
co
rpo
rates a
n ele
ctroni
cs m
odul
e for po
sition control and
positioning feedback. Cont
rol path A
ĺ
AB is closed
when the valve is de-energi
zed.
CAUTIO
N:
The valve is suitable for st
raight-t
h
rou
gh
normally cl
osed or three-way
appli
cations and may be installed
only in a mixing arrangement.
The direction of flow (A
ĺ
AB) must be
as indi
cated on the valve.
The fast posit
ioning time, high resolution and high rangeability make these valves ideal
for modul
atin
g control of chilled and h
o
t water
systems in closed circuits. Sturdy
con
stru
ction
make
s mai
ntenan
ce a
nd regula
r se
rvici
ng unn
ecessary and en
su
res a
long service life.
Ordering
Whe
n usi
ng a
2-1/2 inch flanged valve in
a
straight
-through applicat
ion, a blanking
flange is required for the thi
rd port. If required, order Z
155/65
separately.
For scre
wed
valves, no ad
ditional orderi
ng is re
qui
red
. The comp
on
ents re
qui
red
to
cre
ate a strai
ght-throug
h valve are included with the
valve.
Principles/ Construction
Automatic Control
The co
ntrol
si
gnal is
conve
rted by the micro
processo
r in the electro
nics modul
e into an
output sig
nal
that generate
s a magn
etic
fiel
d in the core. This
causes the only m
o
ving
part, the arm
ature, to change its position
in accordance with the interacting forces
(mag
netic fiel
d, counte
r-sp
ring, hydrauli
cs, an
d so o
n
). The arm
atu
re re
sp
ond
s rapidly
to any chan
g
e
in sign
al, transfe
rri
ng the
corr
esponding movement
directly to the control
disc, enabli
ng fast changes in load to be
corrected qui
ckly and accurately. The valve
positio
n is me
asu
red
contin
uou
sly. The positioni
ng con
troller e
nsure
s an exa
ctly
proportional relationship between the
control si
gnal
and the valve stroke.
Valv
e Chara
cteris
tic
Volumetric flow
10 [V] 10 [V] 20 [mA]
8
6
4
2
0 2 4
100
80 60 40 20
0
[%
]
y
6
12
y y
SVAL0227R1
Control signal
Volumetric flow
10 [V] 10 [V] 20 [mA]
8
6
4
2
0 2 4
100
80 60 40 20
0
[%
]
y
6
12
y y
Sval0012R2
Control signal
Figure 1. Equal-per
cen
tage.
Figure 2. Linear.
In the event of a power failure, or if the pow
er is
swit
ched off, the
spring force
closes the
valve automatically (control
path port
s A
ĺ
AB normal
ly closed).