Liquid heating appliances (electric kettles, coffee machines) come into contact with water and electricity every day, and are frequent visitors to non-compliance reports. Judging from laboratory records, the problems are highly concentrated in dry burn protection, grounding and sealing. This paper takes stock of high-frequency non-conformities under IEC 60335-2-15 and provides rectification directions for enterprises to conduct self-inspection before sending them for formal testing. The full text of the standard can be checkedClassification of regulations and standards。

1. Non-conformance 1: Unreliable dry burning protection

The standard is that the appliance must not catch fire or melt after the water has dried. Many samples rely on a single steam switch, and the contacts stick and do not act during scale or air burning. The rectification is to use dual fuses of steam switch + independent thermostat, or embed a non-resettable over-temperature fuse in the heating plate; at the same time, it is necessary to verify that the performance does not degrade after multiple dry firings. Ningbo Xuntong Standards specially conducts dry firings in the pre-test meeting, and hand over the action temperature and number curve to R & D to avoid relying on a single switch to carry all risks.

2. Nonconformance 2: Ground continuity and creepage distance

If the metal pot body and heating plate are poorly grounded, the shell will be charged when leakage leaks. Common problems include weak welding of grounding terminals and insufficient cross-sectional area of grounding wires. The rectification must ensure that the grounding terminal is reliably crimped, the grounding wire is not smaller than the specified cross-section, and leave margin to prevent pulling and breaking. Ningbo Xuntong standard pre-test will use a grounding resistance meter to measure the impedance of the protective grounding path to meet the standards. This step is often a problem occurred in the random inspection of production line consistency.

3. Nonconformance 3: Sealing and overflow

If water reaches the electrical parts when boiling water overflows to the interfaces and sealing rings of coffee machines and health pots, leakage or short circuit will be triggered. Anti-overflow structures (such as exhaust channels and water retaining ribs) are used for rectification, and heat-resistant silica gel is selected for the sealing ring and compressed; the coupler ensures that liquid cannot penetrate along the outer wall. After completing the rectification, you can compareHome appliance testing servicesList review, or accessNingbo Xuntong Standard Official WebsiteDownload the self-inspection form for liquid heating appliances and digest the risks in advance.