Foreword I
Introduction IV
1 Scope 1
2 Normative references 1
3 Terms and definitions 2
4 Classification and model 3
5 Technical requirements 3
6 Test methods 7
7 Inspection rules 10
8 Marking, instructions, packaging, transportation and storage 11
Table 1 Operating speed codes 3
Table 2 Temperature setting mode codes 3
Table 3 Test parameters for electric strength 4
Table 4 Number of operating cycles 5
Table 5 Axial force of terminal 6
Table 6 End-of-manufacturing inspection items 10
Table 7 Type test items and sequence 11
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 22687-2008 Bimetal temperature controls for household and similar use. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect to GB/T 22687-2008:
——"An operating temperature range from -30℃ to 320℃" is added in the "Scope" (see Clause 1);
——The terms "thermostat", "temperature limiter" and "automatic protection device" are deleted; the Chinese name of the term "operating temperature" is modified; and the terms "operating characteristics of bimetallic elements", "adjustable temperature control" and "snap-action temperature control" are added (see Clause 3 hereof; Clause 3 of Edition 2008);
——A description of "(except for waterproof products)" is added (see 5.1.1.4);
——The requirement or option of "as agreed between the supplier and the purchaser" is added (see 5.2.2 and 5.3);
——The concept of "operating temperature accuracy" is replaced with the concept of operating temperature deviation of specific samples (see 5.3.1 hereof; 5.3.1 of Edition 2008);
——The voltage applying position "between non-homopolar live terminals (of reverse polarity)" is added (see 5.6);
——The technical requirements and test methods for leakage current are deleted (see 5.7 and 6.7 of Edition 2008);
——The description of the allowable temperature change is modified into "not exceeding ±3℃" and "not exceeding ±3%" [see 5.7a) hereof; 5.8a) of Edition 2008];
——Item e) is added in the technical requirements for durability (see 5.14);
——The technical requirements for the resistance grade to tracking of insulating materials are modified [see 5.16c) hereof; 5.16c) of Edition 2008];
——The technical requirements and test methods for operating synchronization are added (see 5.18 and 6.18);
——The technical requirements and test methods for "temperature adjustment width" of adjustable temperature control are added (see 5.19 and 6.19);
——The temperature uniformity and fluctuation requirements for operating temperature test equipment are added (see 6.3.2);
——The allowable value of signal current for operating temperature monitoring is modified (see 6.3.3 hereof; 6.3.3 of Edition 2008);
——The work requirements for calculating the operating temperature accuracy are deleted (see 6.3.8 of Edition 2008);
——The insulation resistance test position - "between non-homopolar live terminals" is added (see 6.4);
——The requirements for contact resistance are modified, and the relevant "Note" is changed to a provision (see 6.5 hereof; 5.5 of Edition 2008);
——The requirement that "the set alarm leakage current shall be 2mA" is added for electric strength test (see 6.6), and the test of leakage current is deleted (see 6.7 of Edition 2008);
——The test temperature and duration of low-temperature resistance test are modified (see 6.7 hereof; 6.8 of Edition 2008);
——The minimum temperature value of high temperature point in high-temperature resistance test is added; and the duration of high-temperature resistance test is modified (see 6.8 hereof; 6.9 of Edition 2008);
——The minimum temperature value of high temperature point and the time at room temperature in thermal shock resistance test are added (see 6.9);
——The content of drop test for packaged samples is added (see 6.13);
——It is specified for the durability test that the load type shall meet the declared requirements (see 6.14);
Introduction
This document is revised in terms of performance indicators with reference to the standards of domestic and foreign advanced enterprises and years of production practice experience and in combination with the current and future manufacturing capacity of domestic bimetal temperature control industry, which can reflect the current domestic design and manufacturing level of bimetal temperature controls.
This document is the basic performance standard for bimetal temperature control products, which systematically and comprehensively includes the technical requirements for manufacturing and acceptance of such products. It gives the technical requirements that the manufacturers need to meet when designing, manufacturing and delivering such products, and also serves as a basis for the purchasers to identify the overall technical level of the products and to accept the products.
Bimetal temperature controls for household and similar use
1 Scope
This document specifies the terms and definitions, classification and model designation, technical requirements, test methods, inspection rules, and marking, packaging, transportation and storage of bimetal temperature controls for household and similar use (hereinafter referred to as "temperature controls").
This document is applicable to the temperature controls, with bimetallic materials as temperature-sensing elements, installed on household and similar electrical appliances, with a rated voltage of not exceeding 690V, a rated current of not exceeding 63A and an operating temperature range from -30℃ to 320℃.
This document is also applicable to the thermostats, temperature limiters and thermal cut-outs as described in GB/T 14536.1-2008.
Note: For temperature controls beyond the scope of this document, the requirements shall be agreed between the user and the manufacturer.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute indispensable provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB/T 2423.3-2016 Environmental testing - Part 2: Testing method - Test Cab: Damp heat, steady state
GB/T 2423.10-2019 Environmental testing - Part 2: Tests methods - Test Fc: Vibration (sinusoidal)
GB/T 2423.17-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Test Ka: Salt mist
GB/T 2828.1-2012 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 14536.1-2008 Automatic electrical controls for household and similar use - Part 1: General requirements
GB/T 22685-2021 Packaging and label on controls for household and similar use
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
Note: The terms "voltage" and "current" used in this document refer to the root-mean-square values (r.m.s) unless otherwise specified.
3.1
bimetal temperature control
temperature-sensitive control that uses bimetallic materials as temperature-sensing elements and keeps the temperature of the controlled object in a certain range by closing or opening the circuit through electric contact during normal operation
3.2
setting temperature
a temperature target value set on a temperature control, i.e., the electric contact is expected to be automatically opened or closed when the temperature rises or falls to this target value under normal operating conditions
3.3
operating temperature
actual temperature value corresponding to a rising or falling temperature which causes the contact of a temperature control to open or close, with the temperature control having a certain setting temperature
Note: It corresponds to the contact opening and closing, and the operating temperature includes the opening temperature and closing temperature.
3.4
differential of open and close temperature
absolute value of the difference between opening temperature and closing temperature when the temperature control has a certain setting temperature
Note: For the manual reset temperature limiters, it refers to the difference between automatic opening temperature and limit manual reset temperature of the contact.
3.5
operating characteristics of bimetallic elements
characteristics of bimetallic elements that the deformation of bimetallic elements shows discontinuous and abrupt change with respect to the temperature change at a specific temperature point when the temperature changes
3.6
adjustable temperature control
temperature control whose setting temperature can be adjusted within a certain range by the end user of the electrical appliance
3.7
unadjustable temperature control
temperature control whose setting temperature is fixed by the manufacturer and cannot be adjusted by the user
3.8
snap-action temperature control
temperature control that has discontinuous and abrupt change in the contact opening gap relative to the temperature change at a specific temperature point when the temperature changes
Note: Snap-action temperature control is also known as quick-jump temperature control.
3.9
slow-action temperature control
temperature control that has continuous change in the contact opening gap relative to the temperature change within the operating temperature range when the temperature changes
4 Classification and model
4.1 Classification
4.1.1 According to operating speed
The classification of temperature controls according to the operating speed and the corresponding codes are shown in Table 1.
