Siemens Building Technology S55155-A110 Actuator

The Siemens Building Technology S55155-A110 Actuator is a professional-grade non-spring return electronic valve actuator designed for precise modulating control in HVAC systems. Engineered for high-performance terminal unit applications, this 24Vac/dc actuator is the direct engineering replacement for the legacy Siemens SSC61U and the European SSC619 models. It seamlessly integrates with Powermite 599 Series MT valves, providing a reliable 65 lbf (300 N) nominal force and a 5.5 mm (7/32-inch) stroke length. Designed for contractors, it features a 0-10 Vdc control signal for granular positioning accuracy and a 30-second run time to ensure efficient thermal response in chilled or hot water circuits.

This Siemens S55155-A110 is UL listed for plenum installations and supports parallel operation of up to 10 units, provided the controller output meets technical requirements. The fail-in-place logic ensures the valve maintains its last commanded position during power disruptions, preventing sudden system fluctuations. For field commissioning, it includes a manual override with a visual position indicator, allowing for simplified setup without specialized tools. This robust electronic actuator is essential for maintaining tight control in HVAC zone control systems, VAV boxes, and fan coil units.

• Direct Compatibility: Engineered as a drop-in replacement for the Siemens SSC61U and SSC619, ensuring no-hassle retrofits.
• Precision Control: Utilizes a 0-10 Vdc modulating signal for exact valve positioning and optimized energy consumption.
• Versatile Powering: Operates on 24 Vac/dc, providing flexibility for various building automation system architectures.
• Plenum Rated: Meets fire and safety standards for installation within air-handling spaces.
• Fail-in-Place Security: Non-spring return design prevents unintended valve cycling during localized power loss.

Is the S55155-A110 compatible with older Siemens SSC61U installations?
Yes, the S55155-A110 is the designated direct replacement for the Siemens SSC61U, utilizing the same mounting footprint and technical parameters.

What happens if the 24V power supply is lost?
As a non-spring return actuator, the unit will fail-in-place, meaning the valve stem remains at its current position until power is restored and a new signal is received.

Can I manually adjust the valve position?
Yes, the unit features a manual override mechanism that allows for manual positioning and includes a visual indicator to verify the stroke status during maintenance.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.