TS IEC 60050-445

TS IEC 60050-445 is the International Electrotechnical Vocabulary part devoted to the terminology of time relays. It provides a common language for devices whose output changes after a defined delay or according to a defined time sequence, helping engineers, authors, and users describe timing behavior with precision and consistency.

What the time-relay terminology covers

This standard addresses terms related to specified-time relays. In general technical usage, a time relay is a control device in which the response is not immediate: the operating or release action occurs after a preset interval, or in a prescribed sequence of timed steps. That distinction matters because timing functions are often central to coordination, sequencing, protection logic, and automation. The vocabulary helps distinguish concepts such as delay, duration, sequencing, and the timing relationship between input action and output response.

Why this edition was revised

The 2010 edition cancels and replaces the first edition published in 2002 and is identified as a technical edition. According to the scope note, the revision brings in terms more commonly used by industry and adds timing charts to clarify definitions involving sequences of operations. It is also identified as a horizontal standard in accordance with IEC Guide 108, meaning the vocabulary is intended to support consistent use across related electrotechnical fields rather than a single narrow application area.

• The core subject is terminology for time relays.
• It focuses on timing-related concepts such as delay, duration, and operation sequence.
• Industry-used terms were incorporated in this edition.
• Timing charts were added to support definitions involving sequences of operations.
• The document has horizontal-standard status for broader electrotechnical consistency.