Istec SpeedSys 200 and SpeedSys 300 Achieve IEC 61508 SIL Certification for Turbine Speed Monitoring
Risknowlogy has independently certified the Istec SpeedSys 200 and SpeedSys 300 turbine speed and acceleration monitoring modules, supplied by Istec International BV and manufactured by Mütec Instruments GmbH, in accordance with IEC 61508 — confirming verified SIL capability for overspeed protection in turbines and rotating equipment.
What Was Certified
The SpeedSys 200 and SpeedSys 300 are speed and acceleration measurement modules used to monitor turbines and other rotating equipment. Both accept pulse inputs from speed probes, convert pulse frequency into speed and acceleration values, compare those values against configurable limits, and act through safety relays and a 4–20 mA current signal. They operate in low-demand mode within safety instrumented functions under IEC 61508 and, where applicable, IEC 61511.
The certification confirms that the safety claims for each module are technically justified, documented, and independently verified for the certified scope. It does not state that the products are superior — it states that their functional safety behaviour has been assessed against a defined standard and conditions of use.
Scope of certification: hardware integrity and reliability requirements, basic safety principles, functional safety management, and user documentation — assessed for both modules in accordance with IEC 61508:2010.
Verified Safety Performance
As part of the certification process, the safety functions implemented by each module were reviewed and verified, including:
- Safety function definition and certified architecture
- Hardware type classification (both modules are Type B hardware)
- Hardware fault tolerance (HFT) at the assessed architectures
- SIL capability of the implemented functions
- Conditions of use and application constraints
The SpeedSys 300 is fit for use in SIL 2 safety functions at HFT = 0 and SIL 3 safety functions at HFT = 1. The SpeedSys 200 is fit for use in SIL 2 safety functions at both HFT = 0 and HFT = 1. In each case the rating holds subject to correct system architecture, application constraints, and the conditions of use stated in the issued certificate.
What This Means for Operators and Stakeholders
Turbine and rotating-equipment asset owners gain confidence that the overspeed protection in their safety instrumented functions is built on validated assumptions and verified reliability data rather than unsupported vendor claims. EPC contractors and system integrators carry less uncertainty during SIL verification and the wider safety lifecycle, because the subsystem-level integrity is already assessed and documented against IEC 61508. Insurers, auditors, and regulators receive independent evidence that the functional safety requirements for these modules have been systematically addressed by a third party rather than self-declared.
About Istec and Mütec
Istec International BV supplies the certified SpeedSys modules, which are manufactured by Mütec Instruments GmbH. Maintaining certified, audit-ready functional safety documentation for both modules demonstrates a commitment to functional safety engineering across the turbine speed monitoring product line.
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