Siemens Building Technologies MXF461…U Series, MXG461…U Series Data Sheet
MXG461…U,
MXF461…U Series
Modulating Control Valves with
Magnetic Actuators
Technical Instructions
Document No. CA1N4455E-P25
April 2, 2013
Description
Features
Product Numbers
Mixing or straight-through valves with magnetic actuators for modulating control of hot
and chilled water systems in closed circuits.
•
Fast positioning time (< two seconds), high-resolution stroke (1:1000).
•
Linear or equal-percentage valve characteristic (user-selected).
•
Switch-selectable control signal: 0 to 10 Vdc, 2 to 10 Vdc, or 4 to 20 mA.
•
Wear-free inductive stroke measurement.
•
Low friction, robust, no maintenance required.
•
Fail-safe feature: A → AB closed when de-energized.
•
Positioning control.
•
Position feedback.
•
Manual control.
See Table 1.
Warning/Caution Notations
Sval0016R1
MXG461…U MXF461…U
Sval0015R1
WARNING:
CAUTION:
Personal injury or loss of life may occur if you do not
follow the procedures as specified.
Equipment damage or loss of data may occur if you
do not follow the procedures as specified.
Siemens Industry, Inc.
Technical Instructions MXG461…U, MXF461…U Modulating Control Valves
Document Number CA1N4455E-P25 with Magnetic Actuators
April 2, 2013
Application
Principles/
Construction
Automatic Control
Valve Characteristic
The MXG461...U (screwed fitting) and MXF461...U (flange fitting) valves are mixing or
straight-through valves with a factory calibrated and mounted magnetic actuator. The
magnetic actuator incorporates an electronics module for position control and
positioning feedback. Control path A → AB is closed when the valve is de-energized.
CAUTION:
The valve is suitable for straight-through normally closed or three-way
applications and may be installed only in a mixing arrangement.
The direction of flow (A → AB) must be as indicated on the valve.
The fast positioning time, high resolution and high rangeability make these valves ideal
for modulating control of chilled and hot water systems in closed circuits. Sturdy
construction makes maintenance and regular servicing unnecessary and ensures a
long service life.
The control signal is converted by the microprocessor in the electronics module into an
output signal that generates a magnetic field in the core. This causes the only moving
part, the armature, to change its position in accordance with the interacting forces
(magnetic field, counter-spring, hydraulics, and so on). The armature responds rapidly
to any change in signal, transferring the corresponding movement directly to the control
disc, enabling fast changes in load to be corrected quickly and accurately. The valve
position is measured continuously. The positioning controller ensures an exactly
proportional relationship between the control signal and the valve stroke.
Volumetric flow
[%]
100
Volumetric flow
[%]
100
80
60
40
20
0
2
4
SVAL0227R1
6
12
10 [V]
86420
10 [V]
20 [mA]
Control signal
Figure 1. Equal-percentage. Figure 2. Linear.
In the event of a power failure, or if the power is switched off, the spring force closes the
80
60
40
20
y
0
y
2
y
Sval0012R2
4
6
12
86420
10 [V]
10 [V]
20 [mA]
y
y
y
Control signal
valve automatically (control path ports A → AB normally closed).
Page 2 Siemens Industry, Inc.
MXG461…U, MXF461…U Modulating Control Valves Technical Instructions
With Magnetic Actuators Document Number CA1N4455E-P25
April 2, 2013
Manual Control
The valve control path (ports A → AB) can be opened
mechanically up to 95% of the full stroke by pressing the
handwheel inward and turning it clockwise (to the
MANUAL position). This disables the control signal from
the controller.
To disable automatic control of the valve, press the
handwheel inward and turn it counterclockwise (to the
OFF position). The valve will close.
For automatic control, the handwheel must be set to the
OFF
AUTO
MANUAL
Sval0006R1
Figure 3. Selecting
Automatic Control.
AUTO position (the handwheel will spring out).
Sizing
Product Numbers
Line
Size
C
V
Δ P
Table 1. MX.461…U - Valves Sizing.
max
Maximum
Close-off
1
S
NA
P
Pressure
med
1
1
I
N
Wire Gauge
18 16 14 12
(in) (gpm) (psi) (bar) (psi) (VA) (W) (A) Cable Length L (ft)
MXG461.15-0.6U 1/2 0.7 44 3 44 29 5 3.15 108 213 361 525
MXG461.15-1.5U 1/2 1.7 44 3 44 29 5 3.15 108 213 361 525
MXG461.15-3.0U 1/2 3.5 44 3 44 29 5 3.15 108 213 361 525
MXG461.20-5.0U 3/4 5.8 44 3 44 29 5 3.15 108 213 361 525
MXG461.25-8.0U 1 9.3 44 3 44 29 5 3.15 108 213 361 525
MXG461.32-12U 1-1/4 14.0 44 3 44 29 5 3.15 108 213 361 525
MXG461.40-20U 1-1/2 23.0 44 3 44 44 6 4.00 66 118 197 328
MXG461.50-30U 2 35.0 44 3 44 44 6 4.00 66 118 197 328
MXF461.65-50U 2-1/2 58.0 44 3 44 46 6 5.00 49 98 164 262
Key:
ΔPmax = Maximum permissible differential pressure across the valve’s control path,
valid for the entire actuating range of the motorized valve.
S
NA = Nominal apparent power for selecting transformer
Pmed = Typical power consumption
IN = Required slow fuse
= Flow rate to IEC534-2-4
C
V
Control path A → AB (normally closed): Tolerance ±5%
Control path B → AB (normally open): Tolerance ±10%
L = Maximum cable length. With four-wire connections, the maximum
permissible length of the separate 16 AWG Cu (copper) signal cable is
656 feet. With three-wire connections, the maximum permissible cable
length is reduced to 1/3 of the values shown in the table.
1 = All data relates to a 24 Vac supply.
Siemens Industry, Inc. Page 3
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