Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Safety standards

ISO 14119

Also known as: EN ISO 14119

ISO 14119 is the international standard covering the principles for design and selection of interlocking devices associated with guards, including guard locking. It classifies interlocking devices by type and addresses how to minimize the possibility of defeating them.

  • Standards
  • Technical documentation

In one sentence

ISO 14119 covers the design and selection of interlocking devices for guards, including guard locking and measures against defeat.

Example

For the sliding door of a CNC machining center with a long spindle run-down, the builder selects a coded interlocking device with guard locking and mounts it so it cannot easily be reached or bypassed.

How it applies

  • Types: Interlocking devices are classified into types 1 to 4, from uncoded mechanically actuated switches to coded non-contact devices, with coding levels for coded actuators.
  • Defeat: Assessing the motivation to defeat an interlock is part of the design. If a guard obstructs normal work, operators will bypass it; the standard asks for design measures such as concealed mounting, coding and plausibility monitoring.
  • Guard locking: Where run-down time exceeds the time to reach the hazard, the guard must stay locked until the hazard has ceased; see guard locking.
  • Technical documentation: The manual should explain the interlock's behavior, how to open guards safely, and that tampering with or bypassing interlocks is prohibited. Maintenance information should cover periodic checks of the device.

ISO 14119 vs. ISO 14120

ISO 14120 covers the design and construction of the guard itself. ISO 14119 covers the interlocking device that monitors a movable guard and connects it to the control system. The safety function formed by guard, interlock and control system is then assessed with ISO 13849-1 or IEC 62061.

By knowledge.aitechdoc.world · Published September 25, 2026 · Last reviewed

Source: ISO 14119, Safety of machinery — Interlocking devices associated with guards — Principles for design and selection

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Knowledge and are not part of any standard.

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