IEC 61511 - suitability of a contactor for a SIF

DrDrreeeaaa · Feb 1, 2018

Hi All

Basic question - what is the basis under which a power contactor is permitted to be used in a SIF to IEC 61508/IEC 61511

The standards require that all components used in the SIS are either certified to IEC 61508 or are determined to be proven in use.

Surely everyone who uses a power contactor in their SIS isn't making a proven in use justification?

Thanks

Michael

controlnovice · Feb 15, 2018

I think Allen Bradly makes some contactors that are "Safety" rated....It's been a long time for me, so I'm not sure if that's the right name for them. I know they make a line of relays that are rated for SIL use.

But I think these contactors are very small...and maybe repurposed relays.

I would think you'd be able to calculate the reduction rate by using the MTBF of the contactor.

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ScottyUK · Feb 17, 2018

This document might help a little - it's obviously intended for ABB's own products, but I suspect the data it contains isn't atypical for components of the same general type.

Unfortunately it refers you to the awful IEC 13849 standard which replaced the altogther more usable EN 954 machinery safety standard.

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IEC 61511 - suitability of a contactor for a SIF

DrDrreeeaaa

Electrical

controlnovice

Electrical

ScottyUK

Electrical

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