Siemens S55180-A157 Electronic Zone Valve Actuator 24VAC 0-10VDC Normally Closed

The Siemens S55180-A157 (SSE161.05U) is an electronic zone valve actuator designed for precise control of hydronic heating and cooling systems. This non-spring return actuator operates on 24 VAC/DC power and accepts a 0-10 VDC proportional control signal for accurate valve positioning.

Key Features:

• Normally closed (NC) configuration with fail-in-place operation
• 0.1-inch (2.5mm) stroke compatible with Siemens 599 Series zone valves
• 34-second stroke time for proportional control
• LED visual position indication for easy status monitoring
• Manual override with 3mm hexagonal wrench
• UL listed for plenum installations
• Compact design with PC+ABS housing material
• Low power consumption at 2.5 VA

This actuator is ideal for HVAC applications including zoned hydronic heating and cooling, radiant floor heating manifolds, fan coil units, and cooling ceiling systems. The proportional control provides precise modulating valve positioning for optimal temperature control and energy efficiency. Compatible with 2-way and 3-way zone valves in sizes from 1/2" to 1" with flow coefficients ranging from 1.0 to 7.0 Cv.