Signaline has today announced that its LocatorPlus and LocatorPlus-EN Linear Heat Detection Controllers have been independently assessed and confirmed capable for use in low demand mode safety functions, up to and including, SIL 2 in accordance with the functional safety framework of IEC 61508.
This Functional Safety Capability Statement confirms their suitability for low demand mode safety functions according to the IEC 61508 standard.
The assessment, performed to IEC 61508 (Edition 2, Parts 1–3), evaluated random hardware failures and architectural constraints for both devices. The published results show SIL 2 architectural capability with a Safe Failure Fraction (SFF) of 92% for each model with quantified dangerous undetected and detected failure rates as part of the documented analysis.
The statement clarifies that capability applies within low demand Safety Instrumented Functions (SIFs) and that full SIF compliance requires system level verification (sensor, logic solver and final element).
These SIL determinations align with the IEC’s functional safety framework, which defines how electrical, electronic and programmable electronic systems reduce risk to tolerable levels across their lifecycle.
IEC 61508 provides the horizontal benchmark for systematic capability, architectural constraints and probability of dangerous failure; parameters used to derive SIL 1–SIL 4 targets for both low demand and high/continuous modes.
Product Context and Approvals
The Signaline LocatorPlus is a dual zone controller and alarm locator for Signaline FT, FT-R and FT-X linear heat detection cables, widely deployed for industrial life safety applications and carrying many established third party approvals (e.g. UL, cUL and FM) alongside its capability statement for SIL2 use in low demand SIFs.
The Signaline LocatorPlus-EN complements the FT-EN cable family, providing dual zone monitoring and automatic alarm location in EN5428 approved systems, now additionally supported by the SIL2 capability for low demand safety functions established under IEC 61508.
Where SIL2 Approval May Be Required & Why Signaline Linear Heat Detection Fits
SIL2 is commonly specified where a measurable risk reduction is required from automated protective functions but where the overall hazard profile does not mandate SIL3 or SIL4. Typical scenarios include:
- Industrial process areas with combustible materials (e.g. conveyors, cable trays, service tunnels) where early heat detection must initiate alarms, interlocks or suppression sequences with defined reliability.
- Energy and utilities infrastructure (fuel storage sites, transformer galleries) requiring dependable initiation of protective actions in low demand conditions where events are infrequent but consequences can be significant.
In these applications, Signaline Linear Heat Detection provides a robust solution: continuous coverage along extended runs, reliable alarm point location and proven integration with conventional and addressable panels.
With LocatorPlus and LocatorPlus-EN now confirmed, SIL2 is capable in low demand mode under IEC 61508. Duty holders can incorporate the controllers into Safety Instrumented Functions that require documented architectural capability and quantified failure behaviour thereby supporting design assurance and compliance.
Most Approved Linear Heat Detection
Signaline is the market leader when it comes to providing approved linear heat detection solutions.
As well as internationally recognised approvals, such as VdS, UL, cUL, FM and UL EU, Signaline has also been approved by country specific bodies, including Activfire, HKFSD, UAE CD and TFTF, making Signaline the most approved Linear Heat Detector on the market.
SIL 2 approval is further proof of our commitment to offering our customers approved solutions. To learn more and download copies of our approvals, please review our certificates page or email sales@lgmproducts.com