This three-way mixing set is commonly used in residential and commercial heating systems to regulate flow distribution. It is typically installed in systems where precise control of hot water or heating circuits is required. The set is suited for applications involving thermostatic control, room temperature regulation, and zoning in central heating systems. Installers working on such systems will find this product suitable for integration with thermostats and building management systems.

Correct sizing and selection of this set depend on the system’s flow requirements and the control strategy. The DN15 connection size and 1/2 inch thread type are standard for many heating applications, ensuring compatibility with common pipe layouts and fittings. The 1.5m cable length allows for flexible positioning of the motor drive relative to the control unit.

Technical parameters

Connecting cable	1.5m
Weight	0.1 kg
Code	SXI46.15/SUA21
Brand	SIEMENS

The 1.5m cable length is suitable for most standard installations, allowing the motor drive to be mounted near the control panel or . The DN15 (1/2 inch) connection ensures compatibility with standard pipe sizes in heating systems. The two-position control mechanism (without a return spring) is ideal for applications where the must remain in the last position until a new signal is received.Installation and connection To install the three-way set, first ensure the system is depressurised and the electrical supply is disconnected. The VXI46 valve is connected using a 1/2 inch Rp thread, which must be sealed with appropriate thread or tape. The SUA21 motor drive is then connected to the valve and wired to the control system. The 1.5m cable should be routed carefully to avoid kinks or damage. A common mistake during installation is incorrect alignment of the motor drive with the valve , which can lead to improper operation. Always verify the valve position and electrical connections before commissioning.Compatibility and accessories This three-way set is compatible with thermostats and control systems that provide two-position switching signals. It is typically used in conjunction with heating circuits, circulation pumps, and sensors. Additional components such as pressure-reducing valves or flow meters may be required depending on the system design. No specific related products are listed for this model.Technical background for designers The VXI46 diverter valve operates by redirecting flow between two outlets based on the position of the actuator. The SUA21 motor drive provides two-position control, meaning the valve moves to either the open or closed position depending on the control signal. The absence of a return spring ensures the valve remains in the last commanded position until a new signal is received. The materials used are suitable for standard heating media such as water or glycol mixtures. The integration into the system depends on the control strategy and the need for precise flow regulation. The service life and efficiency are influenced by the of actuation and the quality of the electrical connections.Service and operation Routine service includes checking the electrical connections for looseness and verifying the valve’s operation by manually testing the actuator. No specific service intervals are provided in the brief. During operation, ensure the system pressure and temperature remain within the manufacturer’s specifications. If the valve fails to respond to control signals, check the wiring and the to the motor drive.Frequently asked questions

Can the SUA21 motor drive be connected to a standard thermostat?
Yes, the SUA21 is compatible with thermostats that provide two-position switching signals. Ensure the wiring matches the control system’s requirements.

Is the 1.5m cable length sufficient for most installations?
Yes, the 1.5m cable is suitable for most standard installations. If longer runs are required, additional cabling may be necessary.

Can this set be used in systems with glycol-based heating media?
Yes, the materials used in the VXI46 valve and SUA21 motor drive are suitable for standard heating media, including glycol mixtures.

What should be checked if the valve does not respond to control signals?
Check the electrical connections for looseness and verify the power supply to the motor drive. Also, ensure the control signal is being sent correctly from the thermostat or control unit.