QBM3230U03UD Siemens Air DP Sensor (S55720-S522)

Datasheet

Siemens QBM3230U03UD Air Differential Pressure Sensor (S55720-S522)

Overview
The Siemens QBM3230U03UD is a precision air differential pressure (DP) sensor engineered for HVAC, VAV, duct, and clean-room applications. Featuring a selectable measuring range of −0.3 to +0.3 inches water column, output options including 0-10V, 0-5V, or 4-20mA, and a built-in LCD display, it delivers both flexibility and accuracy. With a rugged construction, it supports plastic tubing connections and screw-terminal electrical hookup, making installation and configuration easy and reliable.

Differential air pressure sensor for use in HVAC systems. Measuring range is selectable between -0.3″ and + 0.3″ bidirectional. Output is selectable for 0-10V, 0-5V or 4-20mA. Includes LCD display.

Key Features & Benefits

• Selectable Measuring Ranges: −0.3″ to +0.3″ WC (also configurable to smaller spans) to suit various low-pressure applications. Siemens Smart Delivery+1

• Multiple Output Signals: Choose 4-20mA or 0-10V/0-5V depending on your control system input. Apex Controls+1

• Built-In LCD Display: Provides immediate readout for easier setup, calibration, and diagnostics. Apex Controls

• Compact & Robust: Measures about 3.25 × 2.95 × 1.93 in, with reliable tubing connections and screw terminals for durable performance. Apex Controls

• Low-Voltage Operation: Works with 13.5-33 VDC, suitable for many modern HVAC control systems. Apex Controls+1

Technical Specifications

Applications & Use Cases

This sensor is ideal for:

• Monitoring differential air pressure across filters in heating, ventilating, and air-conditioning (HVAC) systems.

• Balancing air flow in VAV (Variable Air Volume) or fan-powered terminals.

• Maintaining clean room or lab environmental conditions by supervising pressure stability.

• Demand control ventilation and energy-saving control strategies.

Installation & Best Practices

• Mount the sensor with pressure connection nipples facing downward to prevent condensation buildup. Apex Controls
• Use push-on plastic tubing (¼-in) with secure fittings.
• Ensure stable supply voltage within specified range (13.5-33 VDC) for proper output.
• Use LCD for initial calibration, zero adjustment, and verifying operation.
• Location should avoid exposure to corrosive or aggressive gases (sensor is for “air and non-aggressive gases”). Siemens Smart Delivery+1

Why Buy From Apex Controls

• We provide the genuine Siemens QBM3230U03UD unit with full spec sheet and support.

• Fast shipping, dependable stock, and OEM guarantee.

• Trusted supplier of sensors and building controls since 1990.