Dwyer Instruments Dwyer AVUB Series Specifications-Installation And Operating Instructions

The Series AVUB Air Velocity Transmitters from Dwyer Instruments
are suitable for measuring air velocity within a duct and giving a 0 to 10 V
linear output. A typical application would be in a VAV air conditioning
system.
The transmitters operate by measuring the heat loss from one of two
sensing elements in the airstream and hence calculating the air velocity.
The special design of these elements makes the transmitter accurate
over the whole air velocity range and gives excellent immunity to drift.
The sensing elements are clad in metal ensuring a long service life and
enabling the sensors to be cleaned easily.
INSTALLATION
Electromagnetic Capability
Series AVUB Air Velocity Transmitters have built in immunity to
electrical interference. However, to achieve full immunity meeting the
standards described below, a screened cable must be used correctly.
The cable screen must be earthed at the enclosure of the
controller/power supply and connected to the screen inside the AVU
casing using the procedure described on the back page. The inside of
the transmitter and the sensing elements near the end of the probe must
be protected from electrostatic discharge at all times.
Attaching the Cable and Cable Screen
The cable gland contains a rubber insert and a plastic insert. Remove
these inserts. Strip back the cable as shown below. Pass the cable
through the gland outer and rubber and plastic inserts. Fold the screen
back over the plastic insert evenly taking care to remove any pieces of
the screen that detach. Feed the cores through into the AVUB and push
the inserts back into the gland noting the orientation of the 3 pipes.
Tighten the gland outer in place. Finally, connect the cores to the
removable 3-way connector.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A.
Series AVUB Air Velocity Transmitter
Specifications - Installation and Operating Instructions
Phone: 219/879-8000
Fax: 219/872-9057
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SPECIFICATIONS
Service: Clean air and compatible, non-combustible gases.
Accuracy: ±8% of full scale.
Response Time (90%): 10 sec (typical).
Temperature Limits: 32 to 104°F (0 to 40°C).
Humidity Limit: 0 to 90% RH, non-condensing.
Power Requirements: 24 VDC or 24 VAC +10% to 15%.
Output Signal: 0 to 10 VDC.
Max. Start Up Current: 60 mA + output current.
Electrical Connections: Screw terminal. Cable gland for 4 to 8 mm wire
(16 gauge wire).
Enclosure Rating: IP67 except sensing point.
Probe Dimensions: 9.45 x .75˝ (240 x 19 mm).
Mounting Orientation: Unit not position sensitive. Probe must be
aligned with airflow.
Weight: 8.8 oz (250 g).
Bulletin AQ-AVUB
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www.dwyer-inst.com
e-mail: info@dwyer-inst.com
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