GB/T 21711.2-2024 Active National standards

GB/T 21711.2-2024 Electromechanical elementary relays—Part 2:Reliability

Publish Date: 2024-03-15 Implement Date: 2024-07-01 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

Basic Information

Standard Code: GB/T 21711.2-2024

Standard Type: National standards

Standard Status: Active

is_force_gb: no

CCS Name: Relays, choppers

ICS Name: Relay

Publish Date: 2024-03-15

Implement Date: 2024-07-01

Pages: 36 pages

Scope

This document specifies the test conditions and rules for evaluating the durability of relays using appropriate statistical methods, in order to obtain their reliability characteristics.
This document is applicable to basic electromechanical relays that are considered non-repairable products (i.e., products that are not repaired after failure). The lifespan of relays is typically expressed in terms of cycle times (CTF). Therefore, when terms such as "time" or "duration" are used in GB/T 34987-2017, they all imply "cycle times". However, under a given operating frequency, cycle times can be converted into corresponding time periods (such as the time to failure, TTF).
This document specifies the failure criteria and derived characteristics for describing the reliability of basic relays in normal use. When the specified failure criteria are reached, the relay is deemed to have failed.
The failure rate of basic relays cannot be considered constant, especially the failure rate caused by wear mechanisms. The failure-free cycle times of tested products typically follow a Weibull distribution. This document specifies methods for calculating approximate values of two-parameter Weibull distributions using numerical and graphical methods, and for confirming the confidence lower limits and methods of reliability values using Weibull Bayesian methods.
This document does not include procedures for additional reliability verification of basic electromechanical relays.
Note 1: This reliability test procedure is specified in IEC 61810-2-1, particularly when basic electromechanical relays are intended to be assembled into safety-related mechanical control systems in accordance with IEC 62061 and GB/T 16855.1. IEC 61810-2-1 stipulates that manufacturers must provide B10D values for such relays.
Note 2: Basic electromechanical relays with robust positioning (mechanical interlocking) contacts in accordance with IEC 61810-3 can provide high diagnostic