Siemens QVM62.1 Owner's manual

QVM62.1
Technical Instructions
Document No. 155-006
October 26, 2006
Air Velocity Sensor
Siemens Industry, Inc.
Description This sensor is used to control the air velocity to a constant value, balance out pressure
fluctuations (supply or exhaust air control), or to monitor the flow in air ducts. It is
primarily used for modulating fan control in primary applications to set the basic volume
flow.
Application The QVM62.1 Sensor records the air velocity as a measured value and converts it to
an active 0 to 10 Vdc output signal. There are three measuring ranges available:
•0 to 16 ft/s (0 to 5 m/s)
•0 to 33 ft/s (0 to 10 m/s)
•0 to 49 ft/s (0 to 15 m/s).
The sensor measures a point (that is it measures the values at a specific location in the
flow profile. For recording the mean air velocity in the duct, the sensor’s immersion
depth is the key measure. The immersion depth depends on the flow profile.
The measurement principle is based on the anemometric measurement principle. The
specially developed thin film sensing element of the QVM62.1 is almost totally
independent from the flow direction and is insensitive to almost any kind of dirt in the
airflow.
Product Number QVM62.1
Operation The air velocity sensor consists of:
•Immersion stem with sensor head and sensing element
•Extension pipe with fitting
•Immersion stem end with flow direction arrow
•Adjustable connecting flange
•Transducer
•Connection cable, screened, four-core, 3 feet (1 m) long

Technical Instructions QVM62.1 Air Velocity Sensor
Document Number 155-006
October 26, 2006
Page 2 Siemens Industry, Inc.
Operation
(Continued) A scale with 0.20 in (0.5 cm) grating on the immersion stem and the extension pipe
indicates the immersion depth.
The connecting flange is used to attach and seal the immersion stem on the duct wall.
A plastic housing with removable cover accommodates the transducer. It can be
screwed to a flat surface.
The sensor cable is connected: the sensor and the transducer are a unit.
The measuring ranges are selected by inserting or removing a plug-in jumper.
Protection against false wiring is provided related to own voltages. (Measuring output
U1 is short-circuit proof.) The sensor head connections are not protected against 24
Vac operating voltage.
Components
Figure 1. Wiring and Setting Elements.
1 Terminal block for connection to the
immersion stem.
2 Terminal block for connection to the
controller.
3. Plug-in unit for setting the three velocity
ranges.
No plug-in jumper = 0 to 16 ft/s
(0 to 5 m/s)
Plug-in on 1 and 2 = 0 to 32 ft/s
(0 to 10 m/s)
(Factory setting)
Plug-in on 2 and 3 = 0 to 49 ft/s
(0 to 15 m/s)
Specifications
Power supply
Operating voltage 24 Vac +/- 20%
Frequency 50/60 Hz
Power consumption < 5 VA (maximum 200 mA)
Output impedance <20 ohm
Measuring data
Measuring ranges, adjustable 0 to 16 ft/s (0 to 5 m/s)
0 to 33 ft/s (0 to 10 m/s)
(factory setting)
0 to 49 ft/s (0 to 15 m/s)
Measuring accuracy at 68°F (20°C), 45% rh, + 0.7 ft/s (0.2 m/s + 3% of measured
1013 hPa value)
Permissible air velocity 66 ft/s (20 m/s)
Direction dependence < 0.3% of measured value at< + 10°
Time constant t90 at 10 m/s ca. 4 seconds
Signal output U1
Voltage 0 to 10 Vdc
Current + 1 mA
Line length Permissible length to controller at:
20 AWG copper cable 164 ft (50 m)
18 AWG copper cable 492 ft (150 m)
16 AWG copper cable 984 ft (300 m)
Line length to the sensor head 3 ft (1 m) (prewired)

QVM62.1 Air Velocity Sensor Technical Instructions
Document Number 155-006
October 26, 2006
Siemens Industry, Inc. Page 3
Connections
Mechanical Screw connection
Electric Screw terminal, maximum 2 × 18 AWG
Degree of protection
Degree of protection provided by enclosures
as per EN 60 529
Transducer IP 42
Sensor head IP 20
Degree of protection as per EN 60 730 III
Environmental conditions
Climatic conditions
Temperature 23°F to 113°F (-5°C to 45°C)
Humidity (non-condensing) <95% rh
Mechanical conditions Class 3M2
Chemical conditions Class 3C2
Storage (transducer and immersion stem)
Temperature 23°F to 113°F (-5°C to 45°C)
Humidity (non-condensing) <95% rh
Mechanical conditions Class 1M2
Transportation
Temperature 23°F to 113°F (-5°C to 45°C)
Humidity (non-condensing) <95% rh
Mechanical conditions Class 2M2
Materials and colors
Housing bottom Polycarbonate, RAL 7001 (silver-gray)
Housing cover Polycarbonate, RAL 7035 (light gray)
Sensor pipes Polycarbonate, RAL 7001 (silver-gray)
Sensor head, extension, enc Polycarbonate, RAL 7035 (light gray)
Connecting flange Polycarbonate, RAL 7001 (silver gray)
Sensor Silicone-free
Weight
With packaging 12 oz (0.352 kg)
Engineering Notes
Place the sensor in a location where the airflow is quiet. Do not place it close to
dampers, registers or duct direction changes.
Figure 2. Sensor Placement.
Use a transformer with safety extra-low voltage (SELV) and separate winding for 100%
ON-time.
Observe all local safety rules and regulations pertaining to sizing and protecting
transformers.
Note the permissible line length to the controller.

Technical Instructions QVM62.1 Air Velocity Sensor
Document Number 155-006
October 26, 2006
Information in this publication is based on current specifications. The company reserves the right to make changes in specifications and models as
design improvements are introduced. © 2006 Siemens Industry, Inc.
Siemens Industry, Inc.
Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089
+ 1 847-215-1000
Your feedback is important to us. If you have
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Document No. 155-006
Printed in the USA
Page 4
Mounting and
Installation Notes Mount the immersion stem so that the air flows through the opening at the sensor head.
The immersion stem is pre-mounted and wired to the transducer on delivery. The
sensor pipes and the end with the direction arrow are prearranged on the connecting
cable; fit them together (use the direction-oriented snap-on connections). If the
extension pipe is not required, remove it from the cable. The connecting flange is not
attached on delivery.
The sensor is supplied with Installation Instructions.
Commissioning
Notes
Check the wiring and air velocity range settings prior to commissioning.
Check the immersion stem position in the air duct (see Installation Instructions).
Wiring Diagram
Figure 3. Wiring Diagram.
G 24 Vac operating voltage
M Measuring neutral/operating voltage
ground
U1 0 to 10 Vdc output signal
Dimensions
Figure 4. Dimensions in Inches (Millimeters).