Modbus Air Pressure Sensor with I/O extension QBM3700.. QBM3700.. air pressure sensor with I/O extension is designed for Modbus RTU communication networks. The QBM3700.. offers easy installation and less plant wiring with HVAC industry wide proven sensor technology. ● ● ● ● ● ● ● ● A6V11684000_en--_b 2019-10-16 Modbus RTU communication interface Two analog inputs for 0...10 V or passive temperature elements Two analog outputs for 0...
Type overview / order data QBM3700.. Modbus air pressure sensor with I/O extension The QBM3700.. comes with one sensor element and with different pressure ranges for power and communication. QBM3700.. Type / ASN Order number / SSN Pressure range Inputs/ outputs MOQ QBM3700-5/MO S55720-S487 1x 0…500 Pa 2 AI, 2 AO 1 QBM3700-13/MO S55720-S485 1x 0…1250 Pa 2 AI, 2 AO 1 QBM3700-25/MO S55720-S486 1x 0…2500 Pa 2 AI, 2 AO 1 Types with 1 sensor Ordering When ordering a QBM3700..
Application Focus segment ● Air handling units (AHU), with communication between controller and field devices and connected to cloud enabling plant digitalization. ● Support of Ecodesign directive ErP 2016/2018 through the use of bus-compatible sensors for monitoring filters, including cloud visualization. Typical use The QBM3700..
Features description and benefits Sensor technology The built-in sensors of the QBM3700.. are based on the unique and in HVAC and automotive industry well-proven ceramic strain-gauge beam technology. ● The accurate sensors with long-term stability for all measured variables are completely maintenance free, providing cost savings over the life of the plant. ● The sensor elements are also suited for demanding applications in the food or pharmaceutical industry.
Operating elements PCB overview LED1 A ON 1 2 3 4 5 6 7 8 9 C B Element Description A Status LED B DIP switches C Button Status LED indicator Color Flashing Function Red Blinking, 1 sec. on, 5 sec. off ● Internal error Red Blinking, 0.1 second on, 1 second off ● Invalid configuration Orange Modulating ● Waiting for on-event addressing Orange Blinking, 1 sec. on, 5 sec. off ● Bus communication failure Orange Blinking, 0.
Interfaces Description 24 V≂ → Power AC 24 V / DC 24 V ⊥ GND 24 V≂ → Power for external device AC 24 V / DC 24 V A+, REF, B- Modbus, RS-485 NOTICE! Not galvanically separated AO1 ← Analog output 1 ⊥ GND AO2 ← Analog output 2 AI1 → Analog input 1 ⊥ GND AI2 AI1 AO2 AO1 B- Ref A+ Terminal AI2 → 6 Smart Infrastructure 24V 24V Terminal Analog input 2 A6V11684000_en--_b 2019-10-16
Technical data Power data Power supply Operating voltage AC/DC 24 V ±15 % Frequency 50/60 Hz Protection class III (SELV / PELV), UL class 2 NOTICE! Limited energy circuit 15 VA or less. Power consumption <2 VA Current draw AC max. 25 mA @ AC 24 V Current draw DC 25 mA @ DC 24 V 24V external power supply for active sensors Max current: 80 mA Function data Expositions Ranges See "Type overview / order data [➙ 2]".
Limits Tolerable overload on one side ● ● On Px +: 10000 Pa On Px -: 400 Pa Rupture pressure ● ● At room temperature: 2x overload At 70 °C: 1.5x overload Media / Admissible temperature Air and neutral gases / 0...70 °C Data for volume flow calculation Permitted k factor range 0...
Communication Modbus RTU communication Element Specification Address range 1...247 (255 = Default) Baud rate 9˙600...57˙600 Format Modbus RTU Line termination Selectable via DIP switch 9 Hardware RS485 Default configuration 9600E1 (9600 baud rate, 1 stop bit, even parity) Cable types Interface Specification Signal lines (Inputs/ outputs) Screw terminals for wire and stranded conductors: ● Wire: 0.5…2.
Inputs and outputs Analog inputs AI1, AI2 Type Area Accuracy Resolution TK/B25/85 Pt1000 -50...+150 °C ±0.5 K 0.1 K 3850 ppm/K LG-Ni1000 -40...+120 °C ±0.5 K 0.1 K 5000 ppm/K NTC10k -40...-25 °C ±1.0 K 0.2 K. 3979 -25...+75 °C ±0.5 K 0.1 K 3979 +75...+100 °C ±1.0 K 0.3 K 3979 +100...+125 °C ±3.0 K 1.0 K 3979 +125...+150 °C ±6.0 K 2.5 K 3979 Ni1000 -50...+150 °C ±0.5 K 0.1 K 6180 ppm/K Input DC 0...
Conformity Ambient conditions and protection classification Classification as per EN 60730 - Degree of pollution 3 Impulse voltage 330 V Degree of protection of housing to EN 60529 IP54 Climatic ambient conditions as per EN 60721-3 Transport/storage ● ● Temperature: -30...+70 °C Air humidity: 5…90 % (non-condensing) Operating ● ● Temperature: -25...
Notes Safety: National regulations CAUTION National safety regulations Failure to comply with national safety regulations may result in personal injury and property damage. ● Observe national provisions and comply with the appropriate safety regulations. Mounting Mounting location QBM3700.. air pressure sensor with I/O extension is suited for direct mounting on air ducts, walls, or in control panels. The following points must be observed.
On the air duct side On the pressure sensor side Tubing with higher pressure side (lower vacuum) Connect to pressure nipple "+". Tubing with lower pressure side (higher vacuum) Connect to pressure nipple "-". Wiring NOTICE Polarity reversal protection The device is short circuit proof and protected against polarity reversal. Each connection is protected against crossover up to maximum supply voltage.
Dimensions QBM3700.. (All dimensions in mm) 146 60 35.5 11.3 5.5 81.9 45 134 9 10 33 42 Front view QBM3700.. Side view QBM3700.. ø6 1 ... 4 93 ø16 151.4 70 28 28 6 FK-PZ1 40 6 3.4 175 78.5 60 100 28 1-4 4 16 6.5 16 Bottom view QBM3700.. (opened cover) Issued by Siemens Switzerland Ltd Smart Infrastructure Global Headquarters Theilerstrasse 1a CH-6300 Zug Tel. +41 58 724 2424 www.siemens.
