JB/T 4088.1-2022 Daily-use metallic tube electric heating elements - Part 1: General requirements
1 Scope
This document specifies the terms and definitions, classification, technical parameters, model designation, technical requirements, test methods, inspection rules, as well as marking, packaging, transportation and storage of daily-use metallic tube electric heating elements.
This document is applicable to the manufacture of metallic tube electric heating elements installed in household electrical appliances, with a rated voltage not exceeding 480V and a single-tube rated power not exceeding 9,000W.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute 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 1804-2000 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications
GB 4706.1-2005 Household and similar electrical appliances - Safety - Part 1: General requirements
GB 4706.12-2006 Safety of household and similar electrical appliances - Particular requirements for storage water heaters
GB/T 17196-2017 Connecting devices - Flat quick-connect terminations for electrical copper conductors - Safety requirements
JB/T 12719-2016 Test method of accelerated life of daily-use metallic tube electric heating elements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
daily-use metallic tube electric heating element
a kind of heating element suitable for household electrical appliances, which utilizes a metallic tube as the case and an alloy heating wire as the heater, with the space between them being filled with dense magnesium oxide powder or similar insulating material as the insulating medium, and is connected to the power supply through a lead-out device. It is hereinafter referred to as the "element"
3.2
heater
component that converts electrical energy into thermal energy
3.3
lead-out rod
metal part that is well-connected to the heater, and is connected to the power supply either directly or through connectors such as male tabs, connecting pieces, or wires attached to it
3.4
lead-out device
general term for the lead-out rods and the male tabs, connecting pieces, wires, and other elements connected to them
3.5
unfolding length
sum of all lengths of both straight and curved sections of the metallic tube in the element
3.6
effective heating length
length of the effective heating portion of the heater in the element
3.7
effective heating surface
surface of the metallic tube corresponding to the effective heating length of the element
3.8
surface effective load
power per unit area on the effective heating surface of the element
3.9
normal operation
operating state of the element under normal use (conditions) when the rated voltage is applied
3.10
working temperature
average temperature of the effective heating surface when the element is in normal operation with the rated input power
3.11
simulation condition
operating conditions where, under the circumstances stipulated in the various clauses and sections of this document, measures are taken to ensure that the average temperature of the heating surface of the element basically matches the working temperature
3.12
damage
it is considered that damage has been caused to the element if any of the following conditions occur:
a) The electrical strength that the element can withstand at the working temperature is less than 75% of the normal specified value;
Foreword IV
Introduction VI
1 Scope
2 Normative references
3 Terms and definitions
4 Classification, technical parameters, model designation
4.1 Classification
4.2 Technical parameters
4.3 Model designation
5 Technical requirements
5.1 Basic requirements
5.2 Information required from the manufacturer
5.3 Safety requirements
5.4 Hygienic requirements
5.5 Requirements for hazardous substance limits
5.6 Performance requirements
6 Test methods
6.1 General test method
6.2 Measurement of rated power
6.3 Measurement of leakage current
6.4 Electrical strength test
6.5 Insulation resistance test
6.6 Overload capacity test
6.7 Sealing test
6.8 Length measurement for element lead-out rod
6.9 Measurement of tube body temperature
6.10 Hydrostatic test
6.11 Tensile test
6.12 Operation life test
6.13 Anti-dry heating test
6.14 Flame resistance test on sealing material
7 Inspection rules
7.1 Inspection classification
7.2 End-of-manufacturing inspection
7.3 Type inspection
7.4 Situations allowing for coverage test
7.5 Miscellaneous
8 Marking, packaging, transportation and storage
8.1 Product marking
8.2 Packaging
8.3 Transportation
8.4 Storage
Annex A (Normative) Model designation rules
Annex B (Informative) Typical structures of elements
Annex C (Normative) Several recommended dimensional criteria for elements
Annex D (Normative) Ultimate working temperatures for case materials commonly used for elements
Annex E (Informative) Additional test requirements for elements used in storage-type electric water heaters
E.1 Hydrostatic test
E.2 Anti-dry heating test
Annex F (Informative) Supplementary test requirements for elements used in washing machines and dishwashers
Annex G (Informative) Method for measuring the heat distribution field of elements using an infrared thermal imager
G.1 Scope
G.2 Requirements for personnel
G.3 General requirements for measuring conditions
G.4 Measurement method specifications
G.5 Image analysis
Annex H (Informative) Recommended power-on/power-off hours for operation life test
Annex I (Informative) Requirements for electrician magnesium oxide used in elements
I.1 Scope
I.2 Technical requirements
I.3 Incoming inspection of raw materials
I.4 Documentation, packaging, and storage
Annex J (Informative) Recommended maximum allowable surface effective loads for elements in common media
Bibliography
Figure B.1 Typical structure of double-ended element
Figure B.2 Typical structure of single-ended element
Table 1 Information required from the manufacturer
Table 2 Deviations of input power from rated power of elements
Table 3 Test voltages corresponding to different rated voltages
Table 4 Lengths of the in-tube portions of the lead-out rods
Table 5 Dimensional deviation of the outer diameters of elements
Table 6 Items, technical requirements and test methods of end-of-manufacturing inspection (for non liquid heating elements)
Table 7 Items, technical requirements and test methods of end-of-manufacturing inspection (for liquid heating elements)
Table 8 Items, technical requirements and test methods of type inspection (for non liquid heating elements)
Table 9 Items, technical requirements and test methods of type inspection (for liquid heating elements)
Table D.1 Ultimate working temperatures for case materials commonly used for elements
Table H.1 Power-on/power-off hours per cycle
Table I.1 Main chemical composition of various types of magnesium oxide
Table I.2 Working temperature ranges of various types of magnesium oxide
Table J.1 Recommended maximum surface effective loads
