Tek-Air VorTek VT-5000 series, VorTek VT-7000 series Installation, Operation & Maintenance Manual
Vortek
AIRFLOW TRANSMITTER
SERIES VT- 5000 & VT-7000
INSTALLATION, OPERATION
& MAINTENANCE MANUAL
RELEASE 2.1
APRIL 2005
PROTECTED BY US PATENT 4,770,035
TEK-AIR SYSTEMS
41 EAGLE ROAD
DANBURY, CT 06810
TEL. (203) 791- 1400
FAX (203) 798-6534
WWW.TEK-AIR.COM
FOREWORD
This manual is designed to provide the user with the information required to install, wire, configure, calibrate,
operate, maintain, and trouble shoot VorTek Air Flow Transmitters. It is important that this manual be read in its entirety
prior to installation and commissioning of VorTek.
While we would like to think that this manual is complete in content and clear in instruction, there may
be questions that we haven’t anticipated. If you have questions that you would prefer to direct to a live
person, we encourage your calls. Technical assistance is available from the service department, at 203-7911400 from 8:30 AM to 5:00 PM ET.
Tek-Air also offers a variety of service and maintenance packages to keep the equipment at peak
performance. For further details contact the Service Department at the above phone number.
WARRANTY
Tek-Air Systems Inc. warrants that the products it manufactures, under normal use and service as described in the Operation and Instruction manual, is free from defects in workmanship and material for a
period of thirty-six months from the date of shipment to the customer. This limited warranty is subject to
the following conditions:
With respect to any repair services rendered, Tek-Air warrants that the parts repaired or replaced will be
in good working condition, under normal use, for the period of the original warranty, or for 90 days from
date of shipment to the customer if the original warranty period has expired.
This warranty is based on the return of the product to Tek-Air’s factory and does not include field repairs.
Periodic maintenance required, as outlined in the Operation and Instruction manual, is the responsibility
of the user.
Unless specifically authorized by Tek-Air in writing, no warranty is made with respect to, and no liability is
assumed in connection with, any goods which are incorporated into other products or equipment by the
Buyer.
The foregoing is in lieu of all other warranties and is subject to the conditions and limitations stated
herein. No other expressed or implied warranty of fitness for particular purpose or merchantability is
made.
The exclusive remedy of the user or purchaser, and the limit of the liability of Tek-Air or any other seller for
any and all losses, injuries, or damage resulting from the use of this product shall be the return of the
product and the refund of the purchase price, or, at the option of Tek-Air or any other seller, the repair or
replacement of the product. In no event shall Tek-Air or any other seller be liable for any incidental or
consequential damages.
Products manufactured by other manufacturers but supplied by Tek-Air carry the original manufacturers
warranty.
Doc.# VT5 OM 050499, Rel. 2.1
TABLE OF CONTENTS
1.0 OPERATION
1.1 General Description.................................................................4
1.2 Specifications .......................................................................... 5
1.3 Operation of VorTek
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Sensors ................................................6
1.4 Transmitter Operation.............................................................. 7
1.5 Options ....................................................................................8
2.0 INST ALLATION
2.1 Probe Bar Mounting and Location...........................................8
2.1.1 Duct-Mounted Probes............................................................................. 8
2.1.2 Fan Inlet- Mounted Probes .....................................................................9
2.2 Transmitter Mounting and Location.......................................10
2.3 Probe Bar and Transmitter Connection................................. 11
2.4 Transmitter Wiring ................................................................. 11
3.0 STARTUP ADJUSTMENTS
3.1 General Description...............................................................12
3.2 Normal Operation..................................................................13
3.3 Damping Adjustment .............................................................13
3.4 Zero Check............................................................................13
3.5 Quick Calibration Check........................................................14
3.6 Threshold Adjustment............................................................14
4.0 CALIBRATION & MAINTENANCE
4.1 Field Calibration ....................................................................14
4.2 Bench Calibration..................................................................15
4.3 Offset Adjustment..................................................................16
4.4 Calibration Check..................................................................16
4.5 Wave Form Check with an Oscilloscope...............................16
4.6 Troubleshooting.....................................................................17
APPENDICES
Appendix A - VorTek Minimum Installation Requirements........... A1
VorTek Duct Probe Installation Diagrams..........A1-A4
VorTek Fan Inlet Probe Installation Diagrams .A5-A10
Appendix B - Cleaning of VorTek Airflow Measuring Probes....... B1
3VORTEK Doc.# VT5 OM 050499, Rel. 2.1
Chapter 1 Operation
1.0 OPERATION
1.1 General Description
The Tek-Air VorTek
insertion probes and an electronic transmitter. The VorTek measurement system
is capable of measuring airflow volume in ducts of all sizes and shapes, as well
as fan inlet bells.
VorTek insertion probes have multiple velocity sensors located along their length.
Each sensor measures airflow velocity using a unique, patented (4,770,035)
application of the digital velocity sensing technique using the principles of vortex
shedding.
Vortex shedding is the generation of eddy currents created by an obstruction in
an air stream. Airflow through each VorTek sensor creates a succession of eddy
currents which are then sensed as pressure pulses. The frequency at which
these pulses are generated, is directly proportional to the velocity of airflow
around the sensor.
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airflow measurement system consists of one or more duct
In large ducts, the profile of the air velocity across a duct is often uneven due to
the bends and transitions in the ductwork. In-line devices such as dampers,
elbows, and transitions also create disturbances in the flow profile. To compensate for these varying velocity profiles, multiple VorTek sensors are utilized within
a duct. The frequency outputs of individual sensors are averaged to obtain the
average duct velocity.
The VorTek transmitter totalizes the frequency signals from the individual sensors
to perform true velocity averaging. From this average, an electronic signal (420mA) is generated for direct input to a customer’s control system.
The VorTek transmitter provides several beneficial features to the user, including
adjustable damping, on-line zero check, on-line calibration, sensor diagnostics,
and optional digital indication. This manual will cover the operation, installation,
startup, and calibration of the VorTek probes and transmitter.
4VORTEK Doc.# VT5 OM 050499, Rel. 2.1
Chapter 1 Operation
1.2 Specifications
Sensors and Probes
Sensor Type: Vortex shedding
Velocity Range: 350 to 9500 FPM
Probe bar Length: 8" to 72"
Probe bar Configuration: Rectangular, Round, Oval, Fan Inlet
Materials of Construction; Standard:
Mounting Plate: Galvanized steel
Probe bar: Extruded aluminum
Sensor Assembly: Aluminum and ABS
Miscellaneous: EPDM finishing strip
Materials of Construction; Fume hood:
Mounting Plate: Stainless steel
Probe bar: CPVC
Sensor Assembly: CPVC and ABS
Materials of Construction; Stainless steel: (High Temp.)
Mounting Plate: Stainless steel
Probe bar: Stainless steel
Sensor Assembly: Stainless steel
Probe bar Support: Mounting Flange Plate and Threaded Rod w/nuts
Sensors Per Probe: 1 to 6 per Bar
Number of Probe bars per Transmitter: 1 to 4 (16 sensors maximum)
Operational Temperature: -20 to 200°F, (160°F for CPVC)
320°F maximum for high temperature
Weight: Function of probe configuration
Transmitter Electronics
Input: One to Sixteen sensors
Output: 4-20mA, fully isolated; 1-5VDC ; 2-10 VDC
Load Capability: 650 ohms
Voltage: 20-28VAC, 60 Hz
Power: 8 VA, .33 amps at 24 VAC
Probe bar Connections: Plug-in cable, Plenum Rated,10 ft. provided
(longer available as a special option)
Calibration: Adjustable from 0 to 7000 for ducts; 0 to 9000 for inlets
Operational Temperature: 0 to 140°F
Frequency Conversion Error: less than ±0.25% FS (8 sensors)
Temperature Error: less than ±0.5% over 25 to 125°F
Signal Damping: 2 or 4 seconds, selectable
Setup & Diagnostic Controls: Zero check, sensor check, Internal Cali
bration Standard: 122 Hz
Dimensions: 7.5" x 7.5" x 3.5" (WxHxD)
Weight: 5 lbs
Mounting: Surface mount for wall, duct, or panel
5VORTEK Doc.# VT5 OM 050499, Rel. 2.1
Chapter 1 Operation
1.3 Operation of VorTek
The VorTek Sensing system measures air velocity by a physical principle called
vortex shedding. The vortex shedding phenomena can be witnessed all around
us in everyday life. Swirling vortices, or eddy currents, are generated whenever
air or liquids flow around an obstruction in their flow path. Common examples are
the eddy currents which develop behind rocks in a stream, and in the fluttering of
a flag behind a flag pole. The flag and the flag pole provide the most visual example of how vortex shedding works.
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Sensors
The flag pole presents an obstruction in
the path of the airflow, which is the wind.
As the wind passes around the flag
pole, vortices (eddies) are created in the
wake of the pole. These vortices, in
accordance with the laws of nature, are
developed and shed in an alternating
manner, from one side of the flag pole to
the other. The evidence of the shedding
of vortices is in the waving of the flag
itself.
Tek-Air’s unique VorTek flow sensors
use a trapezoidal shaped obstruction
placed in a small tube section to generate stable vortices over a wide range of
low velocities. Pressure sensors sense
the passing of individual eddies. Multiple
VorTek sensors are mounted on probe
supports to provide ample coverage of
the duct cross section.
AIR FLOW
High Pressure
Low Pressure
Low Pressure
AIR FLOW
High Pressure
Pulse
No Pul se
No Pul se
Pulse
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Chapter 1 Operation
1.4 Transmitter Operation
The enclosure located on the external end of each duct probe bar is the probe
electronics housing. It contains the electronics which sense the vortices generated by the VorTek probes. At the bottom of the enclosure is the electronic connector required to connect each duct probe to the transmitter. A ten foot long
connecting cable is provided for each duct probe for this purpose.
The VorTek transmitter is capable of accepting inputs from as many as four probe
bars from one measuring station, each with a maximum of four VorTek sensors
each. Up to six sensors may be located on a single probe support bar but the
total number of sensors can not exceed 16.
In the simplest sense, the transmitter electronics can be considered a pulse
frequency-to-analog converter. The transmitter receives electronic pulses from
each of the VorTek sensors. As every pulse represents the same increment of
velocity, the pulses need only be summed together and integrated over time to
determine velocity. Additional circuitry converts the total pulses per second into
analog, 4-20mA signal which is proportional to either CFM or FPM.
The VorTek transmitter consists of a minimum of two circuit boards: the Amplifier
board and the mother board. The amplifier board performs the required signal
conditioning on up to eight VorTek sensor inputs. Either one or two amplifier
boards are provided depending on the number of probe bars used at the station.
The mother board accepts the conditioned pulses from the amplifier board(s),
sums them, integrates them, and converts them into a 4-20mA output signal. The
mother board also provides the power supply, calibration adjustments, internal
calibration standard, and circuitry to drive the optional digital display.
A “PROGRAM MODULE” is installed on the mother board and programs the unit
for the correct number of sensors required for the specific configuration. This
module “plugs-in” and can be changed easily for an alternate configuration if
required.
Because airflow is inherently turbulent, it tends to produce fluctuating electronic
output signals if not damped when high turbulence is present. Also, some commercial direct digital temperature control systems update control outputs only on
changing input signals. The rapid input changes caused by airflow turbulence
can cause these types of systems to effectively overload and crash. To allow the
user to select the damping to meet his application, the transmitter includes a
switch-selectable damping constant of either 2 or 4 seconds.
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Chapter 2 Installation
1.5 Options
Many users prefer to have a digital display as a part of the transmitter. This type
of display is available as an option with the VorTek transmitter. A 3-1/2 digit display is available allowing a display of 0 to 1999 in either CFM or FPM, which is
specified by the customer at the time of purchase. Multipliers of either x10 or
x100 can be used to display up to 200,000 CFM.
2.0 INSTALLATION
The VorTek measurement system consists of two basic elements: the probes and
the transmitter. The VorTek probe bars are inserted into the duct and measure
the velocity of the air moving through the duct. The VorTek transmitter, which is
mounted in close proximity to the probes, converts the electronic pulses generated by the probes into an electronic signal compatible with most DDC control
systems.
The following details are provided on the mounting and installation of the VorTek
transmitter and flow probes. Please read this data carefully and install the equipment in strict accordance with the instructions provided. Should you have any
questions, contact Tek-Air directly.
2.1 Probe Mounting and Location
2.1.1 Duct- Mounted Probes
(refer to drawings on pages A-2 thru A-4 of Appendix A)
General- VorTek probe bars are designed for installation in ducts, regardless of
the duct size. Usually, the larger the duct, the more sensing points are required to
provide an accurate measurement of airflow volume. In a typical application,
multiple probe support bars are directly inserted in the duct. Each probe bar has
multiple VorTek sensors for measurement of the air velocity in the area of the
duct it serves.
T urbulent Airflow- Probe design allows for installation in ductwork without the
requirement for special air straighteners. However, care should be taken to avoid
installation within close proximity to:
• Balancing dampers
• Modulating opposed blade dampers
• Non-airfoil type, parallel-blade dampers
• Elbows
• Transitions
• Humidifiers
• Coils
Refer to the drawing “Minimum Installation Requirements”, Appendix A, page A-1
for the
space is available, probe bars should be located so that they have two thirds of
the straight duct length upstream of the probe bars. Keep in mind that locations
other than those specified as minimums often have areas with very high turbu-
minimum acceptable installation criteria for specific applications. If more
8VORTEK Doc.# VT5 OM 050499, Rel. 2.1
Chapter 2 Installation
lence and reverse flow. Accurate airflow measurement is impossible in these
locations.
Direction of Flow- VorTek airflow probe bars must be mounted so airflow direction corresponds to the direction indicated by the flow arrow on the duct mounting
flange. Failure to mount the units properly will result in an erroneous or no flow
output. Probes can be mounted in any plane, vertical, or horizontal without effecting the measurement quality. Sensors must be mounted straight in the airflow
stream.
Temperature- VorTek probes are designed for use in normal HVAC applications.
Continuous operation with temperatures over 200 degrees with standard materials of construction is not recommended. Fume hood exhaust sensors with CPVC
construction have a limit of 180°. Close proximity to steam humidifiers and coils
is not recommended. Should a steam valve leak when air is not flowing, temperatures in excess of the recommended maximum can occur. Moisture can also
cause incorrect readings.
Airborne Contaminants- Normal dirt and dust associated with air conditioning
applications will not effect sensor performance. The presence of agglomerating
or sticky particles can cause performance problems and should be avoided.
Should this occur, the probe bars can be removed for cleaning (see Appendix C).
Inspection- Carefully unpack and inspect the probes. If probes have been bent
or broken in shipment, advise Tek-Air immediately.
Installation- Probes are mounted across the duct and attach to the duct on both
sides. A 3 3/4" diameter hole should be located on the side of the duct where the
probe will be inserted. A 5/16" diameter hole is required in the duct wall on the
opposite side of the duct for probes longer than 12".
A sensor probe mounting plate is provided with a neoprene gasket and does not
require the application of special sealants. The flange plate should also not be
insulated to allow for easy removal if ever desired. See Diagram, Appenidix A,
Page A-2.
Large ducts need multiple Probe Bars so flow can be averaged. The bars should be
spaced out on the same “plane” of the duct so the sensors are located to pick up
the flow. Refer to the A
, A2, A3,A4 (as required) dimensions on submittal schedule.
1
2.1.2 Fan Inlet- Mounted Probes
(refer to drawings on pages A-5 thru A-10 in Appendix A)
General- The VT-7000 Series Vortek Fan Inlet Probes are in pairs of bars for
each inlet. For single-inlet fans, one pair is provided. For double-inlet fans, two
pairs are provided. One Transmitter serves all bars in the one or two-pair set. On
bars sized for fan inlet diameters of 24" I.D. or less, the bar electronics are
mounted in an enclosure which mounts separately from the bars and is permanently connected to the bars via flexible non-metallic conduit. On bars sized for
fan inlet diameters greater than 24" I.D., the bar electronics are housed in enclo-
9VORTEK Doc.# VT5 OM 050499, Rel. 2.1
Chapter 2 Installation
sures which are mounted in the center of each bar. In both cases the bar electronics connect to the Transmitter via prefab cables, which are factory-connected
to the bar electronics enclosures.
Direction of Flow- The probes must be positioned so that they face into the
airflow: the Safety Cables on the ends of the bars leading
and the mounting brackets facing back into the fan inlet bell. On bars for fan
inlets over 24" I.D., the bar electronics controller has an airflow direction label
affixed to it for your convenience.
Mounting the Probe Bars- Hold the bars in place as shown in the drawing
(choose the drawing that matches the fan type which you are working with).
Make sure the bars are positioned as described above. Mark, on the inlet bell
surface, the mounting hole locations of the brackets on the ends of the bars.
Remove the bars from the inlet and drill pilot holes for #14 self-tapping screws
where you marked them.
out of the fan inlet bell,
Remove the brackets from the ends of the bars (
nuts and Safety Cables). Screw the brackets to the inlet bell surface using thread
locking compound and #14 self-tapping screws.
Re-attach the bars to the installed mounting brackets, being careful to face the
bars in the correct direction, and to re-attach the Safety Cables as they were
before. Tighten the NyLok nuts on the bar mounting bolts sufficiently to prevent
loosening of the nuts through vibration. Note: If a screw, nut, or bolt is stripped,
replace it with the same type fastener. If a drilled pilot hole is stripped, DRILL
ANOTHER HOLE and move the probe according.
DO NOT USE STRIPPED HOLES OR FASTENERS AS DAMAGE TO THE
PROBES AND FAN CAN RESULT FROM PROBES COMING LOOSE AND
BEING DRAWN INTO THE FAN WHEEL!
Stretch the Safety Cables outward from the bars towards the outside of the fan,
leaving no slack in the cable. The eyelet on the end of the cable must be
screwed to a sturdy, metallic surface such as the bell, fan casing, or bearing
support. Mark where you intend to srew the eyelets, and drill #14 self-tapping
screw pilot holes. Using thread locking compound and #14 self-tapping screws,
screw the eyelets down, tighening the screws sufficiently to prevent loosening
due to vibration, but DO NOT STRIP THEM!
be careful not to lose the bolts,
Run the cables out to where the Transmitter will be mounted, leaving sufficient
slack to allow easy plugging and unplugging of the cables into the transmitter
receptacles.
2.2 Transmitter Mounting and Location
General- The transmitter is typically located in close proximity to the duct inser-
tion probe bars and transmits a 4-20mA signal over long distances to the customers control system.
Transmitter Location- The VorTek transmitter is small and designed for mount-
10VORTEK Doc.# VT5 OM 050499, Rel. 2.1
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