Braun A5S vs Istec SpeedSys® 300
In turbomachinery, overspeed protection is critical to preventing failure and ensuring compliance. To help you come to the best decision in choosing the right system, we’ve put out a comparison. In this comparison, we’ll be looking at the Braun A5S and the SpeedSys 300.
Why forward-thinking OEMs, integrators, and end users choose SpeedSys® 300
Established brands usually work with what’s already there for many years, not taking into account customer feedback and improvement points. Istec however, has built new systems from scratch to fulfill all your current day needs in machine protection and monitoring.
Braun A5S
Istec SpeedSys 300
Certified-by-design
The Braun A5S is certified-by-design.
Certified-by-design
The SpeedSys® 300 is certified-by-design, with functional safety requirements embedded directly into the system architecture. SIL 2 and SIL 3 capability are integral to the product design rather than added later.
(Background on this approach: The difference between SIL certification by design and proven in use — Istec)
Standalone protection concept
The Braun A5S can fully function as a standalone protection concept.
Standalone protection concept
The system operates as an independent safety layer, separating overspeed protection from control and monitoring functions.
Modular redundancy approach
The Braun A5S does not have a modular redundancy approach, requiring multiple other modules and systems to function and scale up.
Modular redundancy approach
Redundancy can be implemented using multiple SpeedSys units, supporting flexible 1oo1, 1oo2, or 2oo3 architectures
Integrated safety outputs
Safety relays and outputs are dependent on other parts of the system.
Integrated safety I/O
Safety relays and a safety‑related analog output are available directly on the device, reducing external safety hardware.
Compact and practical design
The Braun A5S does not explicitly note that it is designed for confined spaces or space-constrained installations.
Compact and practical design
Its compact footprint fits space‑constrained installations and retrofit projects, while maintaining full overspeed protection functionality within a single module.
Communication for diagnostics
The A5S does not explicitly note any support for Modbus-communication.
Communication for diagnostics
Modbus RTU over RS‑485 is provided for monitoring and diagnostics.
Standalone and distributed installation
The Braun A5S functions as a fully independent speed protection device, being capable of functioning in a standalone setting.
Standalone and distributed installation
The SpeedSys® 300 is installed as a standalone device, mounted individually in a control or protection panel. Multiple SpeedSys units can be installed side‑by‑side to implement redundancy concepts, without requiring a shared rack, backplane, or central baseplate.
Lifetime Support
SpeedSys 300 delivers a clean architectural separation between control and trip logic ensuring uncompromised protection compared to integrated systems.
SIL3 by Design
Adapt as needed: from single-channel setups to fully redundant 2oo3 architectures, SpeedSys 300 supports stepwise scalability at every stage.
Compact Footprint
Engineered for space-limited panels and demanding environments, it’s ideal for both retrofits and new installations.
| Aspect | Braun A5S | Istec SpeedSys® 300 |
|---|---|---|
| Key features | Overspeed trip functionality, electronic speed monitoring | Overspeed, underspeed, and acceleration protection, SIL2/3 capability, safety relays and safety analog output, external voting, Modbus RS-485 |
| Number of relays | 1 relay | 2 safety relays (DPST), 2 non-safety relays (SPST) |
| Frequency range | 0 Hz to 25 kHz | 0.025 Hz to 35 kHz |
| Hardware response time | < 15 ms (in combination with E16 system) | < 8 ms |
| Number of inputs (active) | No information about number of inputs available | 1 input per module (only one sensor input active at a time) |
| Voting system | Up to 2oo3 included in voting, although it requires multiple sensors | Up to 2oo3 included in voting |
| Outputs | One output, 4-20 mA | • 1 × safety‑rated 4–20 mA analog output • 1 × binary output • 1 × frequency output • Modbus RTU (RS‑485, diagnostics only) |
| Input voltage | 24 VDC | 24 VDC (18 – 36 VDC), dual-redundant power supply |
| Functional safety | TÜV-certified for SIL 3 | SIL 2 / SIL 3 capable; functional safety embedded in system design |
| Stand-alone protection | Complete overspeed protection, independently performed | Yes – each module performs a complete overspeed protection function independently |
| Relay information | 1 trip relay output for overspeed, maximum switching capacity of 30 VDC | 2 safety relays (DPST), 2 non-safety relays (SPST), 1 safety 4-20 mA analog output, 1 frequency output, up to 30 VDC maximum switching capacity. Binary input/output and Modbus RS-485 |
| Rack / backplane mounting | Not listed | Optional 19‑inch rack for mechanical mounting only; no shared backplane or internal bus |
| Reverse scalability | Not listed | Scalable from single module (SIL 2) to redundant |
FAQ
Yes, it’s an independent overspeed protection system, aligned with the requirement that overspeed protection be separate from the control system.
Yes, both systems support redundant architectures.
Both the SpeedSys 300® and the Braun A5S are fit for API 670 environments.
Accuracy disclaimer
All of our comparison pages have been filled in to the best of our knowledge, using publicly available sources. However, we cannot guarantee that they are fully up-to-date or completely correct.
Istec ensures the availability and safety of your rotating machinery by providing the most convenient and accessible hardware solutions, delivered by the world’s leading vibration and speed sensing experts.