Siemens SSB81 elektrinė pavara
- Torque: ~5 Nm (verify in Siemens documentation)
- Control signal: 3-point (open/close, complementary contacts)
- Supply: 24V AC
- Compatibility: Siemens VVI/VVG family and others with matching stem geometry
Where Siemens SSB81 is used
Standard Siemens actuator for control valves in heat substations, where control comes from a Siemens digital controller (RVD140-A, RVD145, RMH760, RMK770). The 3-point control is a simple and reliable scheme: the controller sends "open" or "close" pulses, the actuator moves gradually to the target position. Widely used in multi-family substations and medium-load commercial buildings.
Technical specifications (verify in Siemens catalogue)
| Parameter | Value |
|---|---|
| Code | SSB81 |
| Manufacturer | Siemens |
| Series | Siemens SSA/SSB (actuators for small and medium valves) |
| Type | Rotary/linear electric actuator, 3-point |
| Torque / force | ~5 Nm / ~300 N (verify in Siemens documentation) |
| Control signal | 3-point (S1/S2/S3 wires) |
| Supply | 24V AC ±10 %, 50/60 Hz |
| Power consumption | ~5-10 W (verify in Siemens documentation) |
| Full stroke time | ~60-150 s (depends on variant) |
| Compatible valves | Siemens VVI/VVG series and others with matching stem geometry |
| Protection class | IP54 |
| Ambient temperature | -10 → +50 °C |
| Manual override | Yes (wrench or button, per variant) |
Where and how it is used
Typical scenario: Siemens RVD140-A controller calculates the desired substation supply temperature, sends "open" or "close" pulses to the SSB81 actuator which turns a Siemens VVG31 (or equivalent) 3-way control valve. The valve doses primary DH supply through the heat exchanger — the secondary supply temperature stays stable regardless of DH parameter fluctuations.
Compatible valves
- Siemens VVI series — 2-way control valves DN15-DN50
- Siemens VVG series — 3-way control valves (mixing/diverting) DN15-DN50
- Other manufacturers' valves with matching stem geometry (project-specific confirmation)
When to choose SSB81
- Standard kit for Siemens RVD/RMH controller substations
- Medium-load control valves DN15-DN25
- When 3-point logic is sufficient for the controller (no BMS position feedback required)
- When original Siemens solution compatibility (warranty, service) matters
B2B delivery and logistics via Amegata.lt
- 24-hour delivery across the EU (from our warehouse in Vilnius)
- Competitive B2B pricing — often below market average
- 30-day payment terms for companies (per contract)
- Free technical consultation on actuator and valve pairing
Official Siemens catalogue: siemens.com/hvac
Frequently asked questions
How does SSB81 differ from Belimo LR24A?
Similar construction (24V, rotary actuator, 5 Nm), but they differ: (1) SSB81 is typically 3-point (open/close), Belimo LR24A comes as both 3-point (LR24A) and modulating (LR24A-SR); (2) stem couplings differ — SSB81 is designed for Siemens valves, Belimo LR24A for Belimo CCV; (3) market positioning (Belimo slightly more common in HVAC).
Can it be used with Ouman or Danfoss controllers?
Technically yes, if the controller has a 3-point output (most do). In practice, common pairs are: Danfoss ECL 310 + Danfoss AMV actuators (original set); Ouman A203/C203 + Ouman AB2 (original) or SSB81 (if in stock). Compatibility should be verified case by case.
How to diagnose SSB81 failure?
Symptoms: (1) valve position does not change even with control pulses — check 24V supply and signal wires, (2) audible movement but the valve does not open — mechanical link between actuator and stem (common issue after long service), (3) actuator moves erratically or too slowly — motor or gearbox wear.
Is a separate 24V transformer required?
Yes. Siemens RVD140-A is a 230V controller; to use the 24V SSB81 actuator either (a) a 24V AC transformer (typically 20-40 VA), or (b) a 230V version of SSB (e.g. SSB61 or equivalent) is required. Confirm the supply scheme before ordering.
