What Is Glow Wire — IEC 60335?
The glow wire test is a test in which the tip of a wire heated to a defined temperature is pressed onto the specimen with a specified force, observing ignition, flame duration and the formation of flaming drips.
Purpose of Glow Wire — IEC 60335
The purpose is to assess the fire-initiation risk when insulation and housing materials inside the appliance come into contact with an overheating component.
Which Products Is Glow Wire — IEC 60335 Applied To?
- Electrical-appliance housing and internal-insulation parts
- Terminal blocks and enclosures
- Switches, sockets and switchgear
- White-goods plastic components
In Which Sectors Is Glow Wire — IEC 60335 Used?
Standards Related to Glow Wire — IEC 60335
- IEC 60335Safety in home and similar electrical devices test
- IEC 62368Security in audio, video and information technology devices test
- IEC 61010Safety in measuring, control and laboratory devices test
Glow Wire — IEC 60335 Conditions
- Wire temperature
- The level determined by the product standard; common values are 550, 650, 750, 850 and 960 °C
- Application time
- Generally 30 s
- Applied force
- Constant force defined in the standard
- Beneath the specimen
- A defined layer is used for the flaming-drip assessment
Equipment for Glow Wire — IEC 60335
- Glow-wire test rig
- Temperature-measurement thermocouple system
- Timer and observation rig
- Ventilated test cabinet
Sample Requirements for Glow Wire — IEC 60335
- The specimen may be a real part or a sheet conforming to the standard
- Thickness must represent the worst-case thickness in use
- Generally three specimens are required
- The conditioning required by the standard is applied before the test
Duration of Glow Wire — IEC 60335
The test is short per specimen; a set, including conditioning, is generally completed within one working day.
Glow Wire — IEC 60335 Procedure
- 1Wire temperature and the application point are determined per the product standard.
- 2The wire is heated to the target temperature and verified.
- 3The wire tip is pressed onto the specimen with the defined force for the defined duration.
- 4Ignition, flame duration and the formation of flaming drips are observed.
- 5The flame's extinction time is recorded after the wire is withdrawn.
Glow Wire — IEC 60335 Acceptance Criteria
It is evaluated per the product standard. A common criterion is that the flame extinguishes within a specified time after the wire is withdrawn, the underlying layer does not ignite, and no flaming drips form.
Evaluation of Results
Flame duration, whether ignition occurred, and drip behaviour are evaluated together. The result may also be expressed as the material's GWIT or GWFI value.
Glow Wire — IEC 60335 Report
- Applied standard and revision
- Wire temperature and application time
- Specimen description and thickness
- Observed flame duration and drip behaviour
- Assessment result
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- LVD 2014/35/EU
- Household and similar appliance safety standards
Electrical Safety — What Does This Testing Field Cover?
The section below describes the field that the Glow Wire test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Electrical safety testing shows that a device poses no risk of electric shock, fire or injury to the user in normal use and under foreseeable fault conditions. This family is the test group most often requested when a product enters the market; almost every electrically operated product passes through this gate.
The logic of the field rests on a single assumption: FAULTS WILL HAPPEN. Insulation will age, a component will short, a cable will break, the user will misuse the device. Standards therefore test not only normal operation but also single fault conditions. The sentence "the device works correctly" is not evidence in this field; the evidence is that the device stays safe when it fails.
Assessment addresses three layers together. In the constructional layer, insulation distances (creepage and clearance), protective barriers, earthing continuity, enclosure strength and component selection are examined — this layer is largely a matter of inspection and measurement rather than testing. In the electrical layer, dielectric strength, leakage current, insulation resistance and behaviour under fault conditions are measured. In the thermal layer, temperature rise in normal and abnormal operation is monitored; an overheating component is both a fire risk and a risk of insulation breakdown.
Which standard applies is determined by WHAT THE PRODUCT IS, and that decision affects the entire outcome. Household appliances fall under the IEC 60335 series, information technology and audio/video products under IEC 62368-1, measurement and laboratory equipment under IEC 61010-1, and medical devices under IEC 60601-1. A report obtained under the wrong standard is not accepted in the file even if the measurements it contains are correct.
Component conformity is often overlooked in this field. The safety of the device rests on the conformity of the transformer, optocoupler, fuse, switch and power supply it uses. The list of critical components and the certification status of each is part of the technical file; a change of component reopens the safety assessment.
Method groups in this field
Constructional examination
Insulation distances, barriers, earthing arrangement, accessibility and selection of critical components are examined. It comes before testing and many non-conformities are caught here.
Dielectric strength
It is verified that the insulation withstands the defined voltage. It must not be confused with the routine test on the production line; the type test is more severe.
Leakage current and earthing
The current that could reach the user is measured; the continuity and resistance of the protective earthing path are verified.
Heating tests
Temperatures of components, windings and accessible surfaces are measured in normal and abnormal operation.
Fault condition tests
Components are deliberately short-circuited or open-circuited; the appliance is expected not to cause a fire and not to make a hazardous part accessible.
Mechanical and enclosure tests
Impact, drop, strain relief, IP protection and the safety of moving parts are assessed.
Commonly confused in this field
- A CB certificate is not a CE declaration. CB is the output of a mutual recognition arrangement that eases national certification; the CE declaration is made by the manufacturer under its own responsibility.
- A part of IEC 60335 is not sufficient on its own; it is applied together with Part 1.
- IEC 60950-1 and IEC 60065 have been withdrawn. Old certificates based on these codes cannot be used in a current file.
- Separate certification of the adapter does not cover the conformity of the device; the device is assessed as the system it forms together with its power supply.
- A change of critical component (transformer, fuse, optocoupler supplier) is not a silent change; it requires the safety file to be reviewed.
Which decisions these results support
- CE declaration under the Low Voltage Directive
- IECEE CB certificate and entry into national certification schemes
- Assessing the safety impact of design changes
- Establishing and maintaining the critical component list
- Responding to market surveillance requests
Related Tests
Frequently Asked Questions About Glow Wire — IEC 60335
What is the difference between GWIT and GWFI?
GWIT refers to the highest temperature at which the material does not ignite, while GWFI refers to the temperature at which it meets the specified flame-duration criterion. The two are defined in different parts of the standard and cannot be used interchangeably.
Which temperature level should be applied?
This is determined by the part's function within the device and its proximity to current-carrying components. The level is defined in the product standard; it is clarified together at the quote stage.