Siemens QBE2003-P1 Pressure Sensor

Order No.: S55720-S290

1. Basic Model Definition

QBE2003-P1

QBE: Pressure transmitter series

2003: 3-wire DC 0–10 V voltage output

P: Gauge pressure

1 = Measuring range: 0～1 bar (0～0.1 MPa, 0~100kPa)

Similar form factor current output variant: QBE2103-P1 (4~20mA 2-wire) – do not confuse.

2. Core Electrical Specifications
3. Power supply (identical to QBE2003-P16)

AC 24 V (standard power for BMS DDC controllers)

DC 12～33 V wide-range DC input

Power consumption: ＜7 mA

⚠️ Never connect to AC220V

2. Signal Output

DC 0～10 V, 3-wire system; Load impedance ＞10 kΩ

3. Hirschmann pin assignment (DIN EN175301-803-A)

Pin1: Power positive (AC24V / DC+)

Pin2: 0~10V signal output

Pin3: Common GND (power ground + signal ground)

3. Pressure Performance Parameters

Measuring range: 0～1 bar (0～100kPa) gauge pressure

Accuracy: Typical ±0.3 %FS; Maximum ±0.5 %FS

Response time: ＜2 ms

Maximum overpressure: 3 × FS = 3 bar

Burst pressure: ＞3 bar

✅ Important distinction: Models P1/P1.6/P4 withstand 3×FS overpressure; high-range versions P6/P10/P16 only support 2.5×FS overpressure.

4. Mechanical & Environmental Parameters

Pressure connection: G½” external thread with internal M5 thread (for mounting damping screw to suppress pressure spikes)

⚠️ QBE2003-P10/P16/P25 have no internal M5 thread — this is a key hardware difference between P1 and P16.

Diaphragm material: 1.4404 (316L stainless steel)

Compatible media: Neutral, weakly corrosive liquids/gases (water, glycol mixtures, compressed air, light oil)

Medium temperature: -15 ℃ ~ +125 ℃

Ambient operating temperature: -30 ℃ ~ +85 ℃

Protection class: IP65

Mounting orientation: Any position

5. Typical Application Scenarios (Specialized for 0~1bar low pressure range)
6. Static pressure monitoring of atmospheric tanks and expansion vessels
7. Chilled/hot water static pressure & low-pressure supply circuits in HVAC systems
8. Static pressure measurement for fresh air ducts
9. Low-pressure air supply & low-pressure atmospheric gas pipelines
10. Low-pressure return circuit monitoring on plate heat exchanger units
11. QBE2003-P1 VS QBE2003-P16 Comparison

7. Selection & On-site Troubleshooting Tips
8. This model has a very narrow measuring range. Not recommended if sustained system working pressure exceeds 0.8 bar, as operating point will approach full scale.
9. For applications with severe pressure pulsation, install damping screw via the M5 internal thread.
10. For DDC 0~10V signal acquisition, sensor GND must share common ground with the controller.
11. Install isolation device if medium contains strong acid, alkali or seawater.
12. Not directly interchangeable with the 4~20mA variant QBE2103-P1.

Domestic Replacement Options for Siemens QBE2003-P1 / QBE2003-P16

Mandatory Replacement Prerequisites (All conditions must be satisfied for direct DDC system swap)

✅ Output: 3-wire DC 0~10V

✅ Electrical connector: DIN43650A Hirschmann plug

✅ Pressure thread: G½” external thread

✅ Power supply: Compatible with AC24V / DC12~33V (critical for BMS! Most standard domestic transmitters only support DC24V. Specify AC24V compatibility when placing orders.)

✅ Diaphragm: 316L stainless steel, medium temperature resistance ≥100℃ (suitable for hot water/glycol HVAC systems)

✅ Range selection:

Replacement for QBE2003-P1: 0～1 bar (0～0.1MPa) gauge pressure

Replacement for QBE2003-P16: 0～16 bar (0～1.6MPa) gauge pressure

1. Mainstream Domestic Models (Preferred for HVAC & Building Automation)
2. PCM300 (Universal industry model, widely stocked, cost-effective first choice)

Complete ordering specification example:

PCM300-G1/2-0~1bar-0~10V-Hirschmann-AC/DC24V

PCM300-G1/2-0~1.6MPa-0~10V-Hirschmann-AC/DC24V

Accuracy: ±0.5%FS; ±0.25%FS optional

Medium temperature: -20～125℃; 316L isolation diaphragm

⚠️ Mandatory order remarks: 3-wire 0~10V, AC24V compatible power supply, G1/2 external thread

2. Hongrun OHR-M2 (Widely used in BMS projects, reliable performance)

Model code: OHR-M2-G12-XXX-0~10V

Hirschmann connector & G½ thread available; AC24V customizable

Strong anti-interference against power frequency noise, ideal for installation near pump rooms with variable frequency drives

Accuracy class 0.5, low long-term drift

3. LEEF LFT2010 (Major automation component supplier, consistent batch quality)

Full model: LFT2010-G1/2-0~1bar(0~1.6MPa)-0~10V-DIN connector

Native wide voltage support, AC24V rectifier circuit available on request

Housing dimension highly consistent with Siemens QBE2003, no modification required for mounting space

4. Shangrun SIN-P300

SIN-P300-G1/2-0~0.1MPa / 0~1.6MPa, 0~10V 3-wire, Hirschmann connector

Established domestic instrumentation manufacturer, suitable for bulk project procurement

5. Changhui SWP-ST61 (High-precision alternative)

Customizable: 0~10V output, AC24V supply, G1/2 thread; ±0.25%FS accuracy optional, matching Siemens ±0.3%FS accuracy class

1. Low-Cost Generic Compact Models (For breakdown maintenance & spare parts)

General compact diffusion silicon pressure transmitter form factor:

Verbal specification template to forward to suppliers:

Compact pressure transmitter, DIN Hirschmann connector, G1/2 external thread, gauge pressure 0~1bar (or 0~1.6MPa), 3-wire 0~10V output, power supply AC24V/DC12~33V, 316L diaphragm, max medium temperature 120℃, IP65

III. Critical Replacement Risks & Preventive Guidelines

1. Power Supply Pitfall

Standard domestic versions only support DC24V DC, cannot operate directly with AC24V power from DDC cabinets.

Without pre-customized AC rectification circuit, abnormal operation will occur after power-up!

Original Siemens unit has built-in rectifier and supports AC24V inherently.

2. Thread Specification Check

Default thread for many domestic transmitters is M20×1.5. Explicitly specify G½” (G1/2) external thread, otherwise pipe threads will not match.

3. Special Note for P1 Model Replacement

Siemens QBE2003-P1 base is equipped with M5 internal damping thread; most generic domestic transmitters omit this feature.

If severe pressure fluctuation or water hammer exists on site, an external pressure damper must be installed separately.

4. Pin Assignment Matching

Request domestic transmitter pin definition consistent with original unit:

Pin1=Power positive, Pin2=Signal output, Pin3=Common GND.

Mismatched pinout causes reversed signal or zero output.

5. Temperature Limitations

Standard domestic transmitters usually limit medium temperature to 80℃.

Specify high-temperature variant (max 125℃) for hot water circuits (>90℃) in HVAC systems.

1. Model Selection Priority Recommendation
2. Large-scale commercial projects, long-term continuous use: LFT2010 / OHR-M2 (stable performance & reliable supply)
3. Emergency repair, spare stock, cost control: PCM300 (largest spot inventory)
4. High-precision requirement, precise monitoring for heat exchange stations: SWP-ST61 (0.25 class)