BAPI 53000 Digital CO and NO2 Sensors Instruction Manual
BAPI 53000 Digital CO and NO2 Sensors

Product Identification and Overview

  • Several options for Temperature, Humidity, Carbon Monoxide (CO) and Nitrogen Dioxide (NO2)
  • Field configurable BACnet MS/TP and MODBUS RTU output
  • CO measurement range of 0 to 500 ppm
  • NO2 measurement range of 0 to 20 ppm
  • CO and NO2 sensing elements last approximately 7 years and are automatically self-tested daily
  • Electronic copies of CO and NO2 certificates of calibration available upon request at no extra charge
  • Rough service wall/beam mount or duct mount – perfect for parking structures, equipment rooms or warehouses.

Note:
CO and/or NO2 sensors must be installed and powered within 4 months of purchase to prevent loss of accuracy.

Configuring

These steps are often easier to do before mounting the sensor and can be completed without connecting power to
the sensor. If the sensor is powered while changes are made, power must be cycled for the changes to take effect.

Sensor Address
Each sensor on the RS-485 Line must be assigned a unique address. DIP switches 1 through 8 set the binary address for the sensor. An address of 0 is invalid. (Fig 4)

BACnet and MODBUS Configuration

  1. Use BAPI’s Device Configuration utility and a computer’s USB connection to complete all other configuration changes. The sensor has a USB-C connection.
  2. Download the utility from the Digital CO and NO2 Sensor webpage on BAPI’s website (link below) and follow the instructions for its user guide.
    (Digital CO and NO2 Sensor webpage: https://www.bapihvac.com/product/digital-co-and-no2-sensor/)
  3. MODBUS uses Little-endian for byte order.

Wall Mounting

  1. BAPI recommends using Clean-Cut Tool (part number BA/CLN-CUT-50) to open your wire-entry port to avoid damaging the circuit board.
  2. Mount the unit on a solid, non-vibrating surface 3 to 5 feet (900 to 1500mm) above floor level or as specified by local building codes. Do not mount near supply or return diffuses.
  3. Mount in a horizontal orientation with the enclosure hinge at the top as shown in Fig 1. Mounting in other orientations increases the likelihood that water droplets will touch the sensor elements and damage the sensor.
  4. Use the mounting template on the next page (or the enclosure itself) to to mark the pilot-hole locations. Use the
  5. included #10 (M5) screws on the four mounting feet of the enclosure. A pilot-hole makes mounting easier.
  6. Snug up the screws so that the foam backing is partially depressed but do not over-tighten or strip the screw threads. The foam is for insulation and vibration dampening.
  7. Place the provided #6 screws into the holes on each side of the lid latch to make the cover tamper resistant.
    Wall Mounting
    Fig. 1: Rough service unit wall mounting

Duct Unit Mounting

  1. BAPI recommends using Clean-Cut Tool (part number BA/CLN-CUT-50) to open your wire-entry port to avoid damaging the circuit board.
  2. BAPI recommends placing the sensor in the middle of the duct wall, away from stratified air, to achieve the best reading. The unit should also be a minimum of 3 duct diameters or widths from an elbow, damper or other duct restriction.
  3. Drill a 1” (25mm) hole for the aspiration probe.
    Position the box so that airflow is directly into the holes on one side of the aspiration probe. There are no upstream or downstream holes, the air direction is not important.
  4. Mount the enclosure to the duct using BAPI recommended #10 screws (provided) through a minimum of two of the mounting feet on opposite corners. A 1/8” pilot screw hole in the duct makes mounting easier. Use the enclosure mounting feet to mark the pilot-hole locations.
  5. Snug up the screws so that the foam backing is depressed to prevent air leakage but do not over-tighten or strip the threads.
  6. Use the provided #6 screws to secure the cover for IP66 rating.
    Duct Unit Mounting
    Fig. 2: Duct unit mounting

Mounting Template (Shown actual size)

Mounting Template
Fig. 3: Screw Hole Template. Drill center 7/8” (22mm) hole for rear conduit entry.

Termination

BAPI recommends using twisted pair of at least 22AWG. Larger gauge wire may be required for long runs. All wiring must comply with the National Electric Code (NEC) and local codes.

Do NOT run this device’s wiring in the same conduit as AC power wiring of NEC class 1, NEC class 2, NEC class 3 or with wiring used to supply highly inductive loads such as motors, contactors and relays. BAPI’s tests show that fluctuating and inaccurate signal levels are possible when AC power wiring is present in the same conduit as the signal lines. If you are experiencing any of these difficulties, please contact your BAPI representative.
Connecting Multiple Sensors on the Same RS485 Line

Stop Icon BAPI recommends wiring the product with power disconnected. Proper supply voltage, polarity and wiring connections are important to a successful installation. Not observing these recommendations may damage the product and void the warranty.
Termination

WIRE TERMINATIONS

OUT3
Not used
OUT2/B
BACnet/Modbus RS485
OUT1/A
BACnet/Modbus RS485
GND
Power Ground
V+
15 to 40VDC, 35mA max
18 to 24VAC, 2.7VA max
Fig. 4: Field Wiring Terminals

Connecting Multiple Sensors on the Same RS485 Line

BAPI recommends a maximum of 64 sensors with BACnet and 32 sensors with MODBUS to reduce network congestion. Maximum wire length of 4,000 ft (1,200 m).
Connecting Multiple Sensors
Fig. 5: Multiple sensors connected to the same RS485 Line

Keeping the Enclosure Air Tight After Termination

For the sensor to work correctly, the wiring entrance must remain air tight. If the sensor is mounted to a hollow wall and wired through its back, or wired with conduit, it is possible that a draft of clean air may fill the enclosure through the wiring opening. This draft may prevent the unit from measuring ambient gas. BAPI recommends either a liquid tight fitting or plugging the conduit at the enclosure.

  • Liquid-Tight Fitting – BAPI’s Liquid-Tight Fitting (BA/LTF) allows wire cables of 0.1 to 0.3 inch (2.5 to 7.6mm) to outside diameter to enter the box. Tightening the collar onto the wire cable keeps the wiring entrance air tight.
  • Conduit – Included with the sensor is a foam plug to seal the ½ inch (13mm) EMT. Place the wires into the plug as shown in Fig. 5 and then insert the plug into the conduit sealing the conduit.
    Wires Through Foam Plug
    Fig. 6: Wires Through Foam Plug

Operation

INITIAL POWER UP

  1. The sensor will immediately begin sending readings upon power up. However, allow 3 hrs for the CO and NO2 sensing elements to warm up before their readings can be considered accurate.

NORMAL OPERATION

  1. The unit will automatically perform a self-test every 24 hours to assure that the CO and NO2 sensing elements are not at end of life.
  2. The self-test typically takes 1 minute to run, but may take up to 15 minutes. During the self-test, the sensor reports its last CO and/or NO2 reading prior to the start of self-test.
    a. A failed self-test for BACnet is indicated by the Reliability property of the object showing “Communication Failure.”
    b. A failed self-test for MODBUS is indicated by the dead Count register of the object showing 10 or greater.

MODBUS Map

Sensor Table
SensorInput TypeRange (min)Range (max)Unit TypeUnits of Measure
CO5050096PPM
NO2702096PPM
Temperature (°F)9-4015864°F
Temperature (°C)10-407062°C
Relative Humidity11010029%

MODBUS Map continued…

The sensors in the Sensor Table are listed in priority order. The registers that are used are dependant on the priority order and which are present.

For example:

  • A sensor that includes only CO and NO2 will assign CO to the Sensor 1 registers and NO2 to the Sensor 2 registers. rev. 10/01/24
  • A sensor that includes only NO2, Temperature, and Humidity will assign NO2 to the Sensor 1 registers, Temperature (°F) to the Sensor 2 registers, Temperature (°C) to the Sensor 3 registers, and Humidity to the Sensor 4 registers.
Function 3 Registers
NameLocationData TypeRead/WriteValueNotes
Firmware Version0x4000uint16[8]Rxx123456
Sensor Serial Number0x4008uint16[10]RBAP xxxxxxx
Baud Rate0x406Cuint32R/W9600Use BAPI Device Configuration utility to edit.
Stop Bits0x406Fuint16R/W0Use BAPI Device Configuration utility to edit.
Parity0x4070uint16R/W0Use BAPI Device Configuration utility to edit.
Sensor 1 Input Type0x408Cuint16Rsee Sensor TableNumber code for the type of sensor.
Sensor 1 Range (min)0x408Efloat32Rsee Sensor TableThe min sensor value for normal operation.
Sensor 1 Range (max)0x4090float32Rsee Sensor TableThe max sensor value for normal operation.
Sensor 1 Unit Type0x4092uint16Rsee Sensor TableThe BACnet unit type. See https://store.chipkin.com/articles/bacnet-engineering-units-enumerations
Sensor 1 Poll Interval0x4096uint16R1000The polling rate of the sensor in milliseconds.
Sensor 2 Input Type0x40BAuint16Rsee Sensor Table
Sensor 2 Range (min)0x40BCfloat32Rsee Sensor Table
Sensor 2 Range (max)0x40BEfloat32Rsee Sensor Table
Sensor 2 Unit Type0x40C0uint16Rsee Sensor Table
Sensor 2 Poll Interval0x40C4uint16R1000
Sensor 3 Input Type0x40E8uint16Rsee Sensor Table
Sensor 3 Range (min)0x40EAfloat32Rsee Sensor Table
Sensor 3 Range (max)0x40ECfloat32Rsee Sensor Table
Sensor 3 Unit Type0x40EEuint16Rsee Sensor Table
Sensor 3 Poll Interval0x40F2uint16R1000
Sensor 4 Input Type0x4116uint16Rsee Sensor Table
Sensor 4 Range (min)0x4118float32Rsee Sensor Table
Sensor 4 Range (max)0x411Afloat32Rsee Sensor Table
Sensor 4 Unit Type0x411Cuint16Rsee Sensor Table
Sensor 4 Poll Interval0x4120uint16R1000
Sensor 5 Input Type0x4144uint16Rsee Sensor Table
Sensor 5 Range (min)0x4146float32Rsee Sensor Table
Sensor 5 Range (max)0x4148float32Rsee Sensor Table
Sensor 5 Unit Type0x414Auint16Rsee Sensor Table
Sensor 5 Poll Interval0x414Euint16R1000
Function 4 Registers
NameLocationData TypeNotes
Sensor 1 Output Value0x3002float32The sensing element value.
Sensor 1 Dead Count0x3004uint16The dead Count of the sensor. Will increment each time a communication failure happens and resets to 0 upon each successful sensor reading.
Sensor 2 Output Value0x3008float32
Sensor 2 Dead Count0x300Auint16
Sensor 3 Output Value0x307Afloat32
Sensor 3 Dead Count0x307Cuint16
Sensor 4 Output Value0x3080float32
Sensor 4 Dead Count0x3082uint16
Sensor 5 Output Value0x3086float32
Sensor 5 Dead Count0x3088uint16

Maintenance

The unit should be vacuumed clean once a year or more, depending on the rate of accumulation of any dust or dirt.
To avoid sensor damage, the unit MUST NOT be submerged in any liquids. Hosing or splashing of the unit with any liquids must also be avoided and may void the warranty

Diagnostics

POSSIBLE PROBLEMS:POSSIBLE SOLUTIONS:
General troubleshooting
  • Determine that the input is set up correctly in the controller’s and building automation software.
  • Check wiring for proper termination
  • Check for corrosion at either the controller or the sensor. Clean off the corrosion, re strip the interconnecting wire and reapply the connection. In extreme cases, replace the controller, interconnecting wire and/or sensor.
  • Check that the wiring is good between the sensor and the controller. To do this, label the wires at both ends and then disconnect the wires from the controller and the sensor. With the interconnecting wires separated at both ends, use a multimeter to measure the resistance from wire-to-wire. The meter should read either greater than 10 Meg-ohms, open or OL depending on the style of meter. Now connect the wires together at one end and measure the resistance from wire-to-wire with a multimeter at the other end. The meter should read less than 10 ohms for 22 gauge or larger wire and runs of 250 feet (76m) or less. The resistance may be slightly higher for smaller wires or longer runs. If either test fails, replace the wire.
Unit does not operate
  • Cycle power.
  • Disconnect the power wires from the power source and check for proper power at the source. If the voltage is outside the specifications, troubleshoot the power source. Reconnect power wires to the source when finished
  • Disconnect the power wires at the sensor and verify that the power is the same at the sensor as at the power source. If the voltage is different at the sensor from the source, troubleshoot the wiring. Reconnect power wires to sensor when finished.
  • Measure the power at the sensor with the power wires connected to the power source and to the sensor. If the voltage is outside the limits, but within the limits when the wires are disconnected to the sensor, call your BAPI representative.
Communication issues
  • Typical RS485 troubleshooting steps include the following:
    • Confirm polarity OUT1/A and OUT2/B. Try swapping wires if not sure of the polarity.
    • Confirm all devices share a common RS485 reference (ground).
    • Confirm settings such as baud rate, parity, etc. match on all devices connected to the network.
    • Confirm that the sensor’s DIP switch address is unique on the network, i.e. no other devices use the same address.
    • For BACnet settings, confirm that the max master setting on all devices is higher or equal to the highest address on the network.
    • For BACnet settings, confirm that the device object name and device object number are unique on the network, i.e. no other devices use the same values.

Specifications

Power: 15 to 40VDC, 35mA max | 18 to 24VAC, 2.7VA max
Field Wiring Terminal Blocks: 18 to 24 AWG
Environmental Operation Range:
-4 to 104°F (-20 to 40°C) | 15 to 95%RH Non-condensing
Enclosure Material: UV-resistant Poly carbonate, UL94 V-0
CO and NO2Sensor Element Life: 7 years typical
Agency: RoHS
CO Sensor:
Type: Petrochemical
Range: 0 to 500 ppm
Accuracy: ±6 ppm from 0 to 200 ppm | ±25 ppm from 200 to 500 ppm
NO2 Sensor:
Type: Electrochemical
Range: 0 to 20 ppm
Accuracy: ±0.5 ppm from 0 to 10 ppm
Temperature Sensor:
Range: -40 to 158°F (-40 to 70°C)
Accuracy: ±0.54°F (±0.3°C) from 68 to 104°F (20 to 40°C) [see graph] Humidity Sensor:
Range: 0 to 100%RH
Accuracy: ±2%RH from 20 to 80% @ 25°C
Temperature Accuracy
Dimension
Dimension
Duct Mount
(Dimensions are the same for the rough service unit without the aspiration tube)

Building Automation Products, Inc., 750 North Royal Avenue, Gays Mills, WI 54631 USA
Tel:+1-608-735-4800
Fax+1-608-735-4804
E-mail: sales@bapihvac.com
Web:www.bapihvac.com
BAPI logo

Documents / Resources

BAPI 53000 Digital CO and NO2 Sensors [pdf] Instruction Manual
53000 Digital CO and NO2 Sensors, 53000, Digital CO and NO2 Sensors, NO2 Sensors, Sensors

References

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