SIEMENS QBE3000/3100 differential pressure

Rockwell, Schneider ABB、 Analog input module for Honeywell and other PLCs

Various DDC controllers, data acquisition cards, digital instruments

No additional converters or signal isolators are required (but if there are grounding loop issues, it is recommended to use 4-20mA signals with isolation barriers).

7.2 Electromagnetic Compatibility and Safety

EMC standards: comply with EN 61326-2-3 (industrial environment immunity), EN 61000-6-2 (immunity), EN 61000-6-3 (emission).

CE marking: Complies with Directive 2004/108/EC (now updated to 2014/30/EU).

C-Tick (EMC Australia) has also been certified.

Protection level: Level III (EN 60730), which means safe ultra-low voltage power supply without grounding.

Environmental Product Declaration: Compliant with RoHS hazardous substance restrictions and provides product disposal guidelines (CE1E1922en) to support green building assessments.

Engineering Installation and Debugging Guide

8.1 Installation steps

Mechanical assembly: Fix the installation bracket on a flat surface. Tighten the G1/8 "joint with a wrench (excessive force is not recommended, recommended torque is 5-7 N · m). When connecting 6mm copper pipes, the clamp nut should be fitted first, inserted into the pipeline to the bottom, and then tightened.

Electrical connection: Open the matching DIN plug and connect according to the wiring diagram:

QBE3000 (0-10V): Terminal 1 → Power Supply+(AC/DC), Terminal 2 → GND, Terminal 3 → Signal Output Vout

QBE3100 (4-20mA): Terminal 1 → Power Supply+(DC), Terminal 2 → Signal Output/Power Supply - (Shared Circuit)

(Note: The actual label on the product cover shall prevail, and may be adjusted for different batches.)

Use PG9 connectors to secure the cable and ensure that the sealing ring is in place.

Pipeline exhaust: For liquid media, it is necessary to open the exhaust valve or slightly loosen the upper end joint to exhaust all bubbles. Bubbles can cause output signals to bounce or response to lag.

Power on inspection: Use a multimeter to measure the power supply voltage and confirm that it is within the specified range. Measure the output signal, and the theoretical value at zero pressure difference should be 0 V (or 4 mA). If there is a deviation, check if both sides of the pressure interface are open to the atmosphere (unpressurized).

8.2 Quick Check Table for On site Troubleshooting

Possible causes and solutions for the phenomenon

No output (0V or 0mA) power supply missing, wiring error, output load short circuit check terminal voltage; Check if there is a short circuit between the terminals

The output is always at full range (10V or 20mA). The high pressure side is not pressurized, and the low pressure side pressure is too high; Or confirm the direction of pressure difference due to internal damage; Disconnect the pressure and test the sensor separately

There are bubbles or pulse pressures in the output jumping or unstable medium; Electromagnetic interference pipeline exhaust; Increase damping or buffering; Use shielded cables

Zero drift is large (>0.1V) and the ambient temperature exceeds the range; The sensor is subjected to overvoltage impact to check the temperature of the medium; Factory calibration (usually not on-site zeroing)

Slow response to pressure pipe blockage; Clean the pipeline if it is too long; Shorten the pressure pipe to<10 meters

8.3 Maintenance Suggestions

Sensors do not require regular maintenance (no movable wear parts). But it is recommended to conduct an annual visual inspection to confirm that the cable joints are not corroded and the pressure interface is not leaking. If used for dusty gases, a filtering device can be installed on the low-pressure side to prevent surface deposition of ceramic components from affecting accuracy.

Selection Comparison: QBE3000 vs QBE3100 Decision Matrix

Project QBE3000 (0-10V) QBE3100 (4-20mA)

The optimal transmission distance is ≤ 30 meters ≤ 300 meters

Moderate to strong resistance to electrical noise

Wiring with controller with 3 wires (power+, GND, signal) and 2 wires (loop power supply)

Convenience of fault detection: can directly measure voltage, read and output 0mA when broken, easy to identify

Multi sensor shared power supply can be powered in parallel, but the signal lines need to be independent and the total load of the circuit needs to be calculated

Typical application control cabinet, short distance connection of PLC on-site sensors to remote transmission in the central control room