Dwyer AVUB - Manual

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.
Series AVUB Air Velocity Transmitter
Specifications - Installation and Operating Instructions
Bulletin AQ-AVUB
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: 219/872-9057 e-mail: [email protected]
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).
2-1/4
[57.0]
3-11/32
[85.0]
9-29/64
[240.0]
8-55/64
[225.0]
51/64
[2.0]
3/4
[19.0]