HK Instruments AVT Series User manual

Copyright HK Instruments 2022 www.hkinstruments. Installaon version 7.0 2022
INSTALLATION
INSTRUCTIONS
AIR FLOW AND VELOCITY TRANSMITTERS
AVT Series
Thank you for choosing an HK Instruments AVT series air velocity
transmier. The AVT series is intended for use in commercial environ-
ments. It is designed with a duct mount probe and adjustable collar
suitable for round or rectangular ducts. The AVT series provides sepa-
rate readings for air velocity and temperature.
The AVT series comes with three measurement ranges in a single de-
vice (0–2 m/s, 0–10 m/s, 0–20 m/s). The AVT series is available with
oponal display and relay.
• READ THESE INSTRUCTIONS CAREFULLY BEFORE ATTEMPTING
TO INSTALL, OPERATE OR SERVICE THIS DEVICE.
• Failure to observe safety informaon and comply with instrucons
can result in PERSONAL INJURY, DEATH AND/OR PROPERTY
DAMAGE.
• To avoid electrical shock or damage to equipment, disconnect
power before installing or servicing and use only wiring with
insulaon rated for full device operang voltage.
• To avoid potenal re and/or explosion do not use in potenally
ammable or explosive atmospheres.
• Retain these instrucons for future reference.
• This product, when installed, will be part of an engineered system
whose specicaons and performance characteriscs are not
designed or controlled by HK Instruments. Review applicaons
and naonal and local codes to assure that the installaon will
be funconal and safe. Use only experienced and knowledgeable
technicians to install this device.
• Fuse at load supply (normally 6 A, 10 A, 16 A) does not always limit
the relay output load current to 6 A. Relay Maximum Load (250 V x
6 A res.)
• Add an external fuse to relay common connector. Use a me-lag
fuse (max 6 A) that is in accordance with the standard IEC 60127-2.
The product doesn’t have an internal fuse for the relay.
CAUTION: The product may only be connected to overvoltage
category II electricity network according to IEC 60664-1.
Performance
Measurement ranges:
Velocity:
Range: 0–2 m/s
Range: 0–10 m/s
Range: 0–20 m/s
Temperature: 0−50 °C
Accuracy:
Velocity:
Range: 0...2 m/s: <0.2 m/s + 5 % from reading
Range: 0...10 m/s: <0.5 m/s + 5 % from reading
Range: 0...20 m/s: <1.0 m/s + 5 % from reading
Thermal shi: ±0.8 % FS / °C
Units calibrated at 22 °C. Rapid thermal shi
stabilisaon me 10 min.
Temperature: <0.5 ºC typical @25ºC (velocity > 0.5 m/s)
Technical Specicaons
Media compability:
Dry air or non-aggressive gases
Measuring units:
m/s and °C
Measuring element:
Temperature: ntc10k
Velocity: Pt1000
Environment:
Operang temperature: 0...50 °C
Storage temperature: -20...70 °C
Humidity: 0 to 95 % rH, non-condensing
Physical
Dimensions:
Case : 86.0 x 95.0 x 36.0 mm
Probe: OD 10 mm, length 210 mm from boom of the
cover
Immersion Length with Flange: Adjustable 50–180 mm
Weight:
220 g
Mounng:
Mounng ange, ø 4.0 mm
Materials:
Case: ABS
Lid: PC
Probe: Stainless steel 304
Mounng ange: LLPDP
Protecon standard:
IP54
Display
3 1/2 digit LCD backlit display
Size: 45.7 x 12.7 mm
Electrical connecons:
Power supply & signal out: 4-screw terminal block
16–24 AWG (0.2–1.5 mm2)
Relay Out: 3-screw terminal block
16-24 AWG (0.2–1.5 mm2)
Cable entry:
M16
Electrical
Input: 24 VDC / 24 VAC ± 10 %
Current consumpon 35 mA (50 mA with relay)
+ 40 mA with mA-outs
Output signal 1: (T out)
0–10 V (linear to temperature)
L min 1 kΩ
4–20 mA (linear to temperature)
L max 400 Ω
Output signal 2: (v out)
0–10 V (linear to m/s)
L min 1 kΩ
4–20 mA (linear to m/s)
L max 400 Ω
Relay Out: 3-screw terminal block
(NC, COM, NO)
Potenal free SPDT
250 VAC, 6A / 30 VDC, 6 A adjustable switching point
and hysteresis
Conformance
Meets the requirements for:
CE: UKCA:
EMC: 2014/30/EU S.I. 2016/1091
RoHS: 2011/65/EU S.I. 2012/3032
LVD/EESR: 2014/35/EU S.I. 2016/1101
WEEE: 2012/19/EU S.I. 2013/3113
SPECIFICATIONS
INTRODUCTION
AVT series devices are commonly used in HVAC/R systems for:
• in-duct air ow and velocity monitoring
• in-duct temperature monitoring
• VAV applicaons
APPLICATIONS
WARNING
RoHS
COMPLIANT

Copyright HK Instruments 2022 www.hkinstruments. Installaon version 7.0 2022
SCHEMATICS
DIMENSIONAL DRAWINGS
1) Mount the device in the desired locaon (see step 1).
2) Open the lid and route the cable through the strain relief and
connect the wires to the terminal block (see step 2). Use a separate
strain relief for each cable.
3) The device is now ready for conguraon.
WARNING! Apply power only aer the device is properly wired.
Figure 1a - Mounng a ange
Figure 1b - Mounng the probe in a ange
AVT
71.5
86
m/s
°C
36.0
95
210.0
15.0
15.0
70
Push buon
Terminal block
Jumpers
Terminal block
for relay
Air flow direcon Air flow direcon
Air flow direcon Air flow direcon Air flow direcon
Strain relief facing down
Figure 1c - Mounng orientaon
Tighten the
screw
INSTALLATION
1) Select the mounng locaon (on a duct).
2) Use the mounng ange of the device as a template and mark the
screw holes.
3) Mount the ange on the duct with screws (not included). (Figure 1a)
4) Adjust the probe to the desired depth. Ensure that the end of the
probe reaches the middle of the duct. (Figure 1b)
5) Tighten the screw on the ange to hold the probe in posion.
STEP 1: MOUNTING THE DEVICE

Copyright HK Instruments 2022 www.hkinstruments. Installaon version 7.0 2022
Figure 2a - Wiring diagram: Tout & Vout
Figure 2b - Wiring diagram: relay output
For CE compliance a properly grounded shielding cable is required.
1) Unscrew the strain relief and route the cable(s). Use the strain
relief on the le for power in and signal out (Tout/vout) and the
strain relief on the right for relay.
2) Connect the wires as shown in gure 2a and 2b.
3) Tighten the strain relief.
1) Select the desired measurement range (see step 3).
2) Select the desired measurement mode (see step 4).
3) Congure the relay (oponal) (see step 5).
The device is now ready to be used.
Congure the outputs:
• Temperature output (Tout)
• Velocity output (vout)
Select the output mode, current (mA) or voltage (V), by installing
jumpers as shown in Figure 4. Both outputs, temperature (T)
and velocity (v), are congured separately.
Tout
vout
24 V
GND
+Power supply
24 VDC / 24 VAC
V A VA
Output 0...10 V / 4...20 mA (temperature)
Output 0...10 V / 4...20 mA (velocity)
No jumper
Circuit open
Jumper storedJumper installed
Cicuit closed
(Grey colour indicates that a jumper is installed)
Figure 3b - Jumper installaon
V
Temperature output (Tout): T = voltage (V)
Velocity output (vout): v = voltage (V)
T
v
mA
V
Temperature output (Tout): T = current (mA)
Velocity output (vout): v = current (mA)
T
v
mA
Temperature output (Tout): T = voltage (V)
Velocity output (vout): v = current (mA)
T
v
V mA
Temperature output (Tout): T = current (mA)
Velocity output (vout): v = voltage (V)
T
v
V mA
NC
COM
NO
STEP 2: WIRING DIAGRAMS
CONFIGURATION
STEP 4: SELECTING THE MEASUREMENT MODE
Figure 4
J1 Jumper (J1): Installed
J2 Jumper (J2): Not installed
Range 2 (0–2 m/s)
J1 Jumper (J1): Not installed
J2 Jumper (J2): Installed
Range 10 (0–10 m/s)
J1 Jumper (J1): Installed
J2 Jumper (J2): Installed
Range 20 (0–20 m/s)
Select the measurement range by installing jumpers as shown in
Figure 3a. (See Figure 3a-3b – Jumper sengs)
STEP 3: SELECTING THE MEASUREMENT RANGE
Figure 3a
MOUNTING THE DEVICE COntinued
Figure 1d - Correct posioning of the probe:
minimum straight duct approach
Round ducts:
D = duct diameter
Rectangular ducts:
If there is a horizontal curve or change in the duct size,
D = width of the duct
If there is a vercal curve or change in the duct size,
D = height of the duct

Copyright HK Instruments 2022 www.hkinstruments. Installaon version 7.0 2022
T
v
V mA
sw.p.
hyst.
Tout
vout
24 V
GND
J1
J2
Push button
1. Switching point (display required)
• Install a jumper to pins labeled sw.p. (switching point).
(See Figure 5)
• Press down on the pushbuon to select the switching point (e.g.
5,05 m/s = NC) of the relay. The chosen value (m/s) is shown on the
display.
• Remove and store the jumper aer the conguraon is completed.
2. Hysteresis (display required)
• Install a jumper to pins labeled hyst. (hysteresis). (See Figure 5)
• Press down on the pushbuon to select the hysteresis of the relay
switching point. The chosen value (m/s) is shown on the display.
• Remove and store the jumper aer the conguraon is completed.
NOTE! Relay conguraon jumpers must be removed and stored for
proper operaon.
See the dimensional drawing above
Figure 5
The seller is obligated to provide a warranty of ve years for the deliv-
ered goods regarding material and manufacturing. The warranty period
is considered to start on the delivery date of the product. If a defect
in raw materials or a producon aw is found, the seller is obligated,
when the product is sent to the seller without delay or before expira-
on of the warranty, to amend the mistake at his/her discreon either
by repairing the defecve product or by delivering free of charge to
the buyer a new awless product and sending it to the buyer. Delivery
costs for the repair under warranty will be paid by the buyer and the
return costs by the seller. The warranty does not comprise damages
caused by accident, lightning, ood or other natural phenomenon, nor-
mal wear and tear, improper or careless handling, abnormal use, over-
loading, improper storage, incorrect care or reconstrucon, or changes
and installaon work not done by the seller. The selecon of materials
for devices prone to corrosion is the buyer’s responsibility, unless other-
wise is legally agreed upon. Should the manufacturer alter the structure
of the device, the seller is not obligated to make comparable changes
to devices already purchased. Appealing for warranty requires that the
buyer has correctly fullled his/her dues arisen from the delivery and
stated in the contract. The seller will give a new warranty for goods
that have been replaced or repaired within the warranty, however only
to the expiraon of the original product’s warranty me. The warranty
includes the repair of a defecve part or device, or if needed, a new part
or device, but not installaon or exchange costs. Under no circumstance
is the seller liable for damages compensaon for indirect damage.
RECYCLING/DISPOSAL
The parts le over from installaon should be
recycled according to your local instrucons.
Decommissioned devices should be taken to a
recycling site that specializes in electronic waste.
STEP 5: CONFIGURING THE RELAY RELAY MODEL ONLY
WARRANTY POLICY
Hysteresis represents a dead-zone less than or equal to 20 % of the
range selected. The hysteresis is anchored at the switching point (sw.p.),
extending to the hysteresis range selected.
| | | | | | | |
2 1,75 1,5 1,25 1 0,75 0,5 0,25 0
sw.p.
1,5 m/s
Hysteresis
=
0,25 m/s
Dead
zone
In the above example switching point is set at 1,5 m/s, and hysteresis
is set at 0,25 m/s. As the velocity increases over 1,5 m/s, the relay
will open/close. As velocity reduces, the relay will not close/open
unl the velocity passes 1,25 m/s, thus prevenng rapid cycling.
Hysteresis
Range
m/s m/s
0 – 2 0.4
0 – 10 2
0 – 20 4
Maximum Hysteresis
The hysteresis maximum seng is based on the range selected.
Figure 6
Figure 7
Hysteresis CONTINUED