Dwyer AVFS User Manual
Series AVFS Air Flow Switch
Specifications - Installation and Operating Instructions
AV-AVFS
The new Series AVFS Adjustable Air Flow Switch complements the Dwyer
Instruments line of thermo-anemometer transmitters and handheld instruments.
The AVFS is specifically designed to monitor air flow in ducts and provides a 3A
contact output to indicate a change or loss of flow. Simply turn on the fan or air
handling unit and adjust the set-point via the potentiometer to show normal status.
Then alter a damper or decrease fan speed to activate the AVFS. The AVFS will
signal a loss of flow and the N.O. SPST output will indicate the detected decrease.
For ease of installation and system trouble-shooting, the Series AVFS possesses
a red/green LED indication to provide local status if the air flow is above (green) or
below (red) the set-point. The AVFS provides a +/-5% set-point repeatability across
a full scale range of 1-10 m/s (197-1969 fpm) and includes a mounting bracket for
quick duct mounting. The AVFS Series Adjustable Air Flow Switches come in a
compact, rugged PBT enclosure that is rated NEMA 4X (IP65), making them ideal
for any ventilation system installation or similar BAS application.
Mounting
Mount the airflow monitor by means of the mounting clamp provided. Diameter of
the mounting hole for the unit: .9 in (24 mm) mm. If mounting is to be airtight, use
the gasket provided. The sensing head must be completely immersed into the
airflow and should be in the range of the highest flow velocity, if possible.
Installation depth: min. 1.25 in (32 mm), max. 4.7 in (120 mm).
2 LED
POTENTIOMETER
5-33/64 [140.00]
SPECIFICATIONS
Air Velocity Range: 197-1969 FPM (1-10 m/s).
Temperature Limits: 5 to 122°F (-10 to 50°C).
Humidity Limits: 0-90% RH.
Wetted Materials: PBT Body, Titanium Sensor.
Maximum Pressure: 14.7 psig (1 bar).
Housing: PBT.
Repeatability: 5%.
Contact Rating: 3 A (30 VDC/250 VAC).
Response Time: 3-60 seconds. Varies with flow and set point.
Power Requirement:
AVFS-01: 80...250 AC/DC (47...63 Hz AC).
AVFS-02: 24 VDC ±25%.
Power Consumption: 3 VA.
Electrical Connection: 6.5 ft (2 m) cable.
Enclosure Rating: NEMA 4X (IP65).
Display: 1 Red LED/1 Green LED.
Weight: 7.2 oz (203 g).
Agency Approvals: CE.
29/32
[23.00]
Align the unit in the airflow; the arrow on the cap must point in the direction of flow.
To avoid malfunction a minimum
distance between the air flow
monitor and bends, valves or similar
must be observed.
Electrical Connection
The unit must only be connected by an electrician.
The national and international regulations for the installation of
electrical equipment must be observed.
Voltage supply for units up to 60 V to EN50178, SELV, PELV.
Insert a miniature fuse according to the technical data sheet, if
specified.
• Disconnect power.
• Connect the unit according to the indications per wiring
diagrams.
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: info@dwyer-inst.com
Wiring
AVFS-01
Wire colors
BN brown
BU blue
BK black
WH white
AVFS-02
Wire colors
BN brown
BU blue
BK black
WH white
Adjustment
BN
BK
WH
BU
Note: Miniature fuse to IEC60127-2 sheet 1,
≤ 5 A (fast acting)
BN
BK
WH
BU
L1
+
L
N
-
L
+
L
-
L
• Apply the operating voltage.
• Switch on the flow (preset value) and keep it constant.
1
→ Both LEDs (red and green) light; after approx. 60 s one LED goes off.
If the red LED lights:
• turn the pot slowly clockwise
until the red LED
2
goes off and the green
LED comes on.
If fluctuations as a result of the operating conditions are to be compensated for:
3
• turn the pot further clockwise after the green LED has lit.
After application of the supply voltage both LEDs light for about 60 s, the output
relay is energized (power-on delay time). The unit then is ready for operation.
MAINTENANCE
Upon final installation of the Series AVFS Air Flow Switch, no routine maintenance
is required. The Series AVFS is not field serviceable and should be returned if
repair is needed (field repair should not be attempted and may void warranty). Be
sure to include a brief description of the problem plus any relevant application
notes. Contact customer service to receive a return goods authorization number
before shipping.
If the green LED lights:
• turn the pot slowly counterclockwise until the
green LED goes off and the red LED comes on.
• Turn the pot again slowly clockwise until the
green LED comes on.
©Copyright 2010 Dwyer Instruments, Inc. Printed in U.S.A. 7/10 FR# R1-443803-00
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: info@dwyer-inst.com
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