Air Monitor ELECTRA-flo / SD User manual

Precision Airflow Measurement
An ON
I CON Brand
ELECTRA-o SD
Thermal Airow & Temperature
With BACnet MS/TP or MODBUS RTU Output

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ELECTRA-FLO SD
SAFETY
INFORMATION
This meter was calibrated at the factory before shipment. To ensure correct use of
the meter, please read this manual thoroughly.
Regarding this Manual:
• This manual should be passed on to the end user.
• Before use, read this manual thoroughly to comprehend its contents.
• The contents of this manual may be changed without prior notice.
• All rights reserved. No part of this manual may be reproduced in any form
without Air Monitor’s written permission.
• Air Monitor makes no warranty of any kind with regard to this material,
including, but not limited to, implied warranties of merchantability and
suitability for a particular purpose.
• All reasonable eort has been made to ensure the accuracy of the contents
of this manual. However, if any errors are found, please inform Air Monitor.
• Air Monitor assumes no responsibilities for this product except as stated in
the warranty.
• If the customer or any third party is harmed by the use of this product, Air
Monitor assumes no responsibility for any such harm owing to any defects
in the product which were not predictable, or for any indirect damages.
SAFETY PRECAUTIONS:
The following general safety precautions must be observed during all phases
of installation, operation, service, and repair of this product. Failure to comply
with these precautions or with specic WARNINGS given elsewhere in this
manual violates safety standards of design, manufacture, and intended use of
the product. Air Monitor Incorporated assumes no liability for the customer’s
failure to comply with these requirements. If this product is used in a manner
not specied in this manual, the protection provided by this product may be
impaired.
The following messages are used in this manual:
WARNING: Messages identied as “Warning” contain information regarding
the personal safety of individuals involved in the installation, operation or
service of this product.
CAUTION: Messages identied as “Caution” contain information regarding
potential damage to the product or other ancillary products.
IMPORTANT NOTE: Messages identied as “Important Note” contain
information critical to the proper operation of the product.

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ELECTRA-FLO SD
1.0 INTRODUCTION........................................................................................................................................
1.1 PURPOSE OF THIS GUIDE...............................................................................................................................................
1.2 TYPICAL METER INSTALLATION...................................................................................................................................
2.0 SPECIFICATIONS........................................................................................................................................
3.0 INSTALLATION...........................................................................................................................................
3.1 INSTALLATION ....................................................................................................................................................................
3.2 RECEIVING & INSPECTION.............................................................................................................................................
3.3 PLACEMENT GUIDELINES................................................................................................................................................
3.4 MOUNTING .........................................................................................................................................................................
3.5 POWER/SIGNAL CONNECTIONS..................................................................................................................................
3.6 CONFIGURATION ..............................................................................................................................................................
3.7 START-UP / OPERATION..................................................................................................................................................
3.8 LEDs ........................................................................................................................................................................................
4.0 BACnet MS/TP or MODBUS RTU...............................................................................................................
4.1 CHANGING THE MAC ADDRESS AND DEVICE INSTANCE NUMBER..............................................................
4.2 BACnet PIC STATEMENT...................................................................................................................................................
4.3 AVAILABLE BACnet OBJECTS..........................................................................................................................................
4.4 ADDITIONAL BACnet OBJECT INFORMATION........................................................................................................
4.4.1 Device Object................................................................................................................................................................
4.4.2 Analog Input Objects.................................................................................................................................................
4.4.3 Analog Value Objects................................................................................................................................................
4.5 MODBUS RTU MEMORY MAP.......................................................................................................................................
5.0 MAINTENANCE / INSPECTIONS..............................................................................................................
5.1 TROUBLESHOOTING.........................................................................................................................................................
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TABLE OF CONTENTS

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ELECTRA-FLO SD
1.0 INTRODUCTION We, at Air Monitor, would like to thank you for purchasing our quality, U.S. made,
Thermal Airow & Temperature Measurement System. As our valued customer,
our commitment to you is to provide fast, reliable service and assistance, while
continuing to oer you new products to meet your growing ow measurement
needs.
We have written this guide to provide the persons responsible for the installation,
operation and maintenance of your thermal airow measurement system with the
most specic equipment information they will need. This is NOT an electrical or
HVAC trade manual. This guide is the basic reference tool for the ELECTRA-o/SD
with BACnet MS/TP or MODBUS RTU only.
Air Monitor’s ELECTRA-o/SD accurately measures the average velocity of
owing air by means of thermal dispersion at the surface-mount thermistor
sensor locations in the duct. Temperature is also measured via these thermistors.
Microprocessor based circuitry within the enclosure then converts the rate of
thermal dispersion into average airow velocity and temperature analog signals
which are transmitted via a BACnet® MS/TP or MODBUS® RTU with a customer-
installed cable to the local BMS.
1.1 PURPOSE OF THIS GUIDE
1.2 TYPICAL METER INSTALLATION
VAV Installations Option 1: Locate ELECTRA-flo/SD a
minimum of 3" upstream of the VAV box, or 3" upstream
of the pneumatic flow ring (remove the ring).
3" Upstream
Minimum
1 Duct Diameter
Minimum
VAV Box
Flow Direction
½" Conduit Outlet
Square Duct Round Duct
VAV Installations Option 2: When mounted downstream
of the VAV box, position the ELECTRA-flo/SD a minimum
or one duct diameter downstream of the VAV box.
Equivalent Duct Diameter X
Rectangular Duct: X = 2 (HxW) Circular Duct: X = Duct Diameter
H+W

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ELECTRA-FLO SD
ELECTRA-o/SD
ACCURACY Sensor Accuracy
Velocity: ±2% of reading from 0 – 3,000 FPM
Temperature: ±0.15ºF
Overall System Accuracy
Flow: ±3% of actual ow from 0 – 3,000 FPM
Temperature: ±0.15ºF of air temperature
RANGE Velocity Range: 0 to 3000 FPM
PROBE
ASSEMBLY
Mounting
Standard mounting bracket: 6063 aluminum with four ¼” holes for fasteners. ¼” thick neoprene gasket
Optional Type 316 stainless steel mounting plate
Length: 4”, 5”, 6”, 7”, 8”, 9”, 10”, 12”, 14”, and 16”
Sensors Per Probe
4” probe, one sensor
5”-16” probes, two sensors
Probe
Type: 6063 anodized aluminum. ½” diameter tubing
Optional: Type 316 stainless steel
Sensor Housing: Injection molded polycarbonate, UL94 V-0 rated
Sensor Type: Surface mount precision thermistor
TRANSMITTER Enclosure: NEMA 4 rated. Injection molded polycarbonate UL94 V-0 rated
Electrical Connections: Separate power and signal terminal strips with plug-in connectors
Outputs
BACnet MS/TP or MODBUS RTU
BAUD Rates: 76800, 38400, 19200 or 9600 available by DIP switch
Termination: 120 Ω termination available by DIP switch
Points List: BACnet / MODBUS
Name Object Type Units
Flow Velocity Ai / Holding register Feet per Minute, Meters per Minute
Flow Velocity Pressure Ai / Holding register Inches of Water, Millimeters of Water
Temperature Ai / Holding register Degrees Fahrenheit, Degrees Celsius
Volumetric Flow Ai / Holding register Cubic Feet per Minute, Cubic Meters per Minute
Duct Area Scale Factor AV / Holding register Square Feet, Square Meters
Conguration: Via two 8-position DIP switches
Filter: User selectable via DIP switch – none, light, medium, and heavy
Temperature Limits
–20ºF to 120ºF Transmitter
–20ºF to 120ºF Airow
Humidity Limits: 0 to 99% RH, non-condensing
POWER Power Supply: 24 VAC (20-28 VAC) or 24 VDC (20-40 VDC), automatically selected
Power Consumption: 5 VA or 5 W
Circuit Protection: Power input is isolated, fused, and reverse polarity protected
IMPORTANT NOTE: Specications subject to change without notice.
SECTION 2.0: SPECIFICATIONS

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ELECTRA-FLO SD
3.0 INSTALLATION
The ELECTRA-o/SD is intended for use in 4” to 16” ducts and in VAV terminal
box applications in an environment between -20°F to 120°F where it will not be
exposed to rain or snow. The ELECTRA-o/SD electronics enclosure is designed to
be mounted to the exterior of the duct or VAV box with the sensor probe inserted
through the side of the duct or VAV box.
Carefully remove the ELECTRA-o/SD from the shipping container and inspect for
any damage. If damaged, contact Air Monitor’s Service Department. Verify that
the shipping container includes the four self-tapping mounting screws in addition
to this manual.
Location of the ELECTRA-o/SD is critical for proper operation and accuracy
of the airow measurement. The typical installation diagrams below show the
minimum distance between a source of airow disturbance (elbow, transition,
duct take-o, etc.) and the meter.
• If more than the minimum clearances are available, proportionally adjust
the upstream and downstream distances.
• Avoid locating the ELECTRA-o/SD where it will be subjected to
condensing moisture from a coil.
• Contact Air Monitor’s Applications Engineering Department to discuss any
sub-minimal installation.
3.1 INSTALLATION
3.2 RECEIVING & INSPECTION
3.3 PLACEMENT GUIDELINES
VANED
ELBOW
.75X .5X
0.5X 0.5X 0.5X
1X
.75X1.5X
SWEEP
ELBOW
1X
0.75X
2X
BELLMOUTH INLETS
PLENUM
TAKEOFF
1.5X
DUCT
BRANCH
4X
Rectangular Duct: X = Circular Duct: X = Duct Diameter
Equivalent Duct Diameter X
H+W
2(HxW)
EXPANDING TRANSITION
≤
α
α
≤
ELBOW
UNVANED
REDUCING TRANSITION
2.5X 1X
DAMPERS
α
α
• VAV Installations - Locate the ELECTRA-o/SD a minimum of 3” upstream
of the VAV box or 3” upstream of a pneumatic ow ring (remove the ow
ring). When mounting downstream of the VAV box, position the ELECTRA-
o/SD a minimum of one duct diameter downstream of the box.

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ELECTRA-FLO SD
1. Determine the measurement location based upon the engineer’s plans and
the ELECTRA-o/SD’s minimum placement guidelines.
IMPORTANT NOTE: It may be necessary to remove a portion of external
duct insulation to allow the ELECTRA-o/SD to be securely mounted to the
exterior of the duct wall.
2. Remove the four screws (8-32 x 0.325) that attach the mounting bracket to
the enclosure. Place the mounting bracket against the duct wall where the
ELECTRA-o/SD is to be mounted and trace the large probe insertion hole
in the center of the bracket onto the duct. See Figure 2.
3. Using a 3/4” hole saw, cut the insertion hole.
4. Place the mounting bracket centered over the insertion hole. Align the
edge of the mounting bracket parallel with the axis of the duct, then
attach the mounting bracket to the duct using the provided sheet metal
screws ( 8-32 x 0.75”).
5. Place the probe through the mounting hole, center the gasket in the
hole in the bracket so it makes contact with the duct, then attach the
enclosure to the mounting bracket at the four mounting holes using the
four screws (8-32 x 0.325”) previously removed in Step 3 above.
3.4 MOUNTING
Figure 2

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ELECTRA-FLO SD
The ELECTRA-o/SD provides a eld selectable BACnet MS/TP or MODBUS
RTU output for airow velocity, equivalent velocity pressure, temperature, and
volumetric ow which is scaled based on the present value set to the BACnet
Analog Value 0 (MODBUS Holding Register 8) object.
Power wiring is done at terminal strip J1, and RS-485 signal wiring is done at
terminal strip J2. Both terminal strips are located in the lower corners of the
transmitter and are accessible by removing the enclosure cover. See Figure 3.
One ½” conduit opening is provided in the bottom of the enclosure for power
and signal wiring.
It is recommended that power wiring be 18 awg and signal wiring be 18
awg to 22 awg. 16 awg is the maximum wire gauge that the terminals can
accommodate. To aid the wiring process, terminals J1 and J2 are removable
by pulling the terminal strip straight up and o the circuit board. Once wiring
has been completed replace the terminals by aligning with the receptacle and
pressing rmly.
The ELECTRA-o/SD can be powered by either 24 VAC providing 20-28 VAC or
24 VDC providing 20-40 VDC.
CAUTION: To prevent damage to the ELECTRA-o/SD, the 24 VAC/VDC
power source must be turned o before making the power and signal
connections.
CAUTION: Incoming and outgoing RS485 cable shield wires should be
connected together, but must not be connected to the RS485 ground.
3.5 POWER/SIGNAL CONNECTIONS
Figure 3
RS-485 (+)(B)
RS-485 (-)(A)
RS-485 Ground/Common
J1
Run Mode and
Network Status LEDs
J2
24VAC neutral / 24VDC(-)
24VAC line / 24VDC(+)

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ELECTRA-FLO SD
All device conguration is done using two 8-switch DIP packages labeled S1
and S2 that can be accessed by removing the enclosure cover. The protective
shield over the circuit board also has a reference guide for setting all device
congurations. See Figure 4. Conguration settings can be changed while the
device is powered.
3.6 CONFIGURATION
None
Parity (Modbus only)
Modbus
BACnet*Odd
Even*
IMPORTANT NOTE: * denotes the default setting. All conguration settings
are shipped from the factory in the default mode.
Figure 4
S1 Bank, SW1 & SW2 Parity (MODBUS only)
Down Down None
Up Down Odd
Down Up Even*
S1 Bank, SW5 BACnet / MODBUS
Down BACnet*
Up MODBUS
S1 Bank, SW6 & SW7 Baud Rate
Up Up 9600
Up Down 19200
Down Up 38400
Down Down 76800*
S1 Bank, SW8 – RS-485 Termination
Up Engaged
Down Not Engaged (No Termination)*
S2 Bank, SW1 U.S. / SI Units
Up SI Units
Down US Units*
S2 Bank, SW2 through SW8 BACnet Addressing
7 Bit BACnet MS/TP MAC Address and Instance Number Conguration

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ELECTRA-FLO SD
SW8 Bit0 (Decimal 1)
SW7 Bit1 (Decimal 2)
SW6 Bit2 (Decimal 4)
SW5 Bit3 (Decimal 8)
SW4 Bit4 (Decimal 16)
SW3 Bit5 (Decimal 32)
SW2 Bit6 (Decimal 64)
1. After completion of all power and signal wiring, activate the 24 VAC /
24 VDC power source
2. Observe the Run Mode indicator located in the upper left corner of
the board. See Figure 3 on page 8. After a brief initialization period
the Run Mode LED will begin blinking on/o in ½ second intervals
indicating normal operation.
3. Conrm the BACnet or MODBUS output is being correctly received by
the BMS.
4. Replace the cover of the ELECTRA-o/SD making sure not to pinch any
wires and secure in place with the four screws. Do not over tighten.
3.7 START-UP / OPERATION
3.8 LEDs
Alarm Flash Sequence – Error Codes
One Flash = Cal Error
Two Flashes = Sensor 1 Bad
Three Flashes = Sensor 2 Bad
Four Flashes = No Cal Data
Six Flashes = Unknown Error
NET and DBG LEDs will blink with network trac when network
communication is established with the ELECTRA-o/SD.
Flash
On/O
Flash
On/O
RUN ALARM NET DBG
Normal
Mode
Alarm
Mode
Denotes Flashing LED