Siemens SSC131.39U - User Manual

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Summary

Use Cases and Technical Design

3-Position Control Signal

Explains the behavior of the SSC131.39U actuator with a 3-position control signal (voltage at Y1/Y2).

Control Signal, Indication, and Ordering

DC 0...10 V Control Signal Behavior

Details how the valve opens/closes proportionally to the DC 0-10 V control signal at Y.

Notes, Safety, and Commissioning

Engineering and Connection Notes

National Safety Regulations

Warns about potential personal injury and property damage from non-compliance with national safety regulations.

Mounting and Orientation Guidance

Provides warnings for mounting and instructions on actuator orientation relative to the valve.

Self-Calibration and Manual Operation

Actuator Self-Calibration Process

Explains that actuators self-calibrate upon receiving operating voltage to find their stroke endpoints.

Electrical Fail-Safe Function

Details the fail-safe mechanism for SSC161.35U/131.39U, including capacitor charging and return to fail-safe position.

Manual Actuator Stem Adjustment

Explains how to move the actuator stem manually using a 3-mm Allen wrench and a button.

Manual Operation Refinement and Cabling

Manual Operation Release and Calibration

Explains how to release the actuator from manual mode, triggering a self-calibration.

Cabling and Terminal Connections

Technical Data

Power Supply Specifications

Details operating voltage, frequency, power consumption, and fuse/breaker rating for the actuators.

Signal Input and Parallel Operation

Covers control signal types, input impedance, and limits for parallel operation of actuators.

Signal Output and Operating Parameters

Describes feedback signal, output current/voltage, resolution, and operating data like positioning force and stroke.

Electrical Connections, Standards, and FCC

Compliance Standards and Certifications

FCC Regulations and Interference

The Siemens Electromotoric Actuator, available in models SSC161.05U, SSC161.35U, and SSC131.39U, is designed for precise control of Powermite MT Series 2-way and 3-way globe valves. These actuators are primarily used in chilled ceiling, VAV, unit ventilators, fan coil units, and other terminal unit applications within building management systems.

Function Description:

The actuators convert an electrical control signal into a mechanical stroke, which is then transmitted to the valve stem to regulate fluid flow. The SSC161.05U (fail-in-place) and SSC161.35U (fail-safe) models operate with a modulating control signal of DC 0...10 V, providing proportional control where the valve opens or closes in proportion to the control signal. At DC 0 V, the actuator stem is retracted, fully closing normally closed valves and fully opening normally open valves. These modulating variants also provide a DC 0...10 V position feedback signal, proportional to the actuator stem's stroke. The SSC131.39U (fail-safe) model uses a 3-position (floating) control signal (AC 24 V). With voltage at Y1, the stem extends; with voltage at Y2, the stem retracts. If no voltage is applied to Y1 or Y2, the actuator maintains its current position. In the event of a power failure, the SSC131.39U actuator fails with the stem fully retracted. All actuators feature self-calibration to the valve stroke, ensuring accurate operation. Modulating variants also provide a position feedback signal.

Important Technical Specifications:

Operating Voltage:
- SSC161.05U, SSC161.35U: AC/DC 24 V (± 15% for AC, ± 20% for DC)
- SSC131.39U: AC 24 V (± 20%)
Control Signal:
- SSC161.05U, SSC161.35U: Modulating DC 0...10 V
- SSC131.39U: Floating AC 24 V (3-position)
Power Consumption (Normal Operation):
- SSC161.05U: 3.5 VA (AC); 1.5 W (DC)
- SSC161.35U: 3.5 VA (AC); 1.5 W (DC)
- SSC131.39U: 3 VA (AC); 1.5 W (DC)
Positioning Force: 67 lbf (300 N)
Stroke: 0.05" to 0.25" inch (1.2...6.5 mm)
Running Speed (for 5.5 mm stroke):
- SSC161.05U, SSC161.35U: 5 s/mm (27.5 s ± 25%)
- SSC131.39U: 16 s/mm (88 s ± 25%)
Permissible Temperature of Medium in Connected Valve: 34 to 248°F (1...120°C)
Input Impedance: 100 kOhm
Feedback Signal (Modulating Actuators Only): DC 0...10 V (Max. output current 1 mA, Resolution 1:100)
Parallel Operation: Max. 10 modulating actuators or 24 floating actuators (provided controller output is sufficient). Note: SSC131.39U floating fail-safe actuators cannot be run in parallel with legacy SSC81.5U actuators. For parallel operation of floating fail-safe SSC actuators, all actuators in parallel must be the same part number.
Housing Protection Degree: NEMA 2 / IP20 (EN 60529)
Housing Color: 2003, Ti-Gray (Cover/base: PC + ABS)
Connecting Nut: Brass, 3/4" inch
Dimensions: 104 mm (4.1") length, 49 mm (1.9") width, 95.6 mm (3.8") height
Weight:
- SSC161.05U: 9.7 ounces (276 g)
- SSC161.35U: 10.5 ounces (298 g)
- SSC131.39U: 10.5 ounces (298 g)

Usage Features:

Direct Mounting: The actuators are designed for direct mounting onto Powermite MT Series valves using a coupling nut, requiring no special tools.
Self-Calibration: Upon application of operating voltage, the actuators automatically self-calibrate from fully retracted to fully extended to the setpoint. Correct calibration requires a valve stroke greater than 0.05 inch (1.2 mm). If calibration fails, the actuator attempts another calibration after 10 seconds. After three failed attempts, the stem remains in the extended position.
LED Indication: An LED provides visual feedback on the actuator's status, including stem retracting/extending, stem position (H0-H40, H40-H60, H60-H100), fail-safe status, calibration, error, manual operation, and ultra-cap initial charging.
Manual Override: A manual override feature allows for manual positioning of the actuator stem using a 3-mm Allen wrench. To engage manual mode, open the cover, press and hold down button (a) for at least three seconds. The actuator will ignore control signals from the controller in this mode. Rotating the Allen wrench (b) clockwise moves the stem down, and counter-clockwise moves it up. To release manual operation, press and hold button (a) again for at least three seconds, initiating a self-calibration.
Electrical Fail-Safe Function (SSC161.35U, SSC131.39U only): These models feature an ultra-capacitor that stores energy for fail-safe operation. Upon initial power connection or after a power failure, the capacitor charges for up to 180 seconds, during which the actuator cannot respond to control signals. In the event of a power failure lasting more than 5 seconds, the actuator returns to its fail-safe position within 30 seconds.
Cabling Operation: The terminal block is easily accessible by unscrewing the cover and removing the cover. Wires can then be connected or disconnected, and the terminal block and cover re-installed.
Commissioning: During commissioning, both wiring and actuator functioning should be checked. The actuator must be commissioned only with a correctly mounted valve in place.
Orientation: The actuator should be mounted above horizontal.

Maintenance Features:

Maintenance-Free: The actuators are designed to require no maintenance.
Repair: The actuators cannot be repaired; if a fault occurs, the complete unit must be replaced.
Disposal: The device is considered electronic waste and must be disposed of through appropriate channels, complying with all local and currently applicable laws and regulations.
Safety Precautions: During any service work, the operating voltage must be switched off. If necessary, electrical connections should be disconnected from the terminals. It is crucial to observe national safety regulations and avoid using pipe wrenches, pliers, or similar tools, as well as lateral pressure or cable tension on the mounted actuator.