all-pole disconnection: disconnection of both supply conductors by a single initiating action or, for multi-phase appliances, disconnection of all supply conductors by a single initiating actionNOTE For multi-phase appliances, the neutral conductor is not considered to be a supply conductor. Single-phase power: An AC power system composed of one live wire and one neutral wire.Three-phase…
intentionally weak part: A part intended to rupture under abnormal operating conditions to prevent the occurrence of a condition that could impair compliance with this standard.NOTE: Such a part may be a replaceable component, such as a resistor or capacitor, or a part of a component to be replaced, such as an inaccessible thermal link…
8.1.5 Live parts of built-in appliances, fixed appliances, and appliances delivered in separate units shall be protected by at least basic insulation before installation or assembly. Compliance is checked by inspection and the test in 8.1.1.Why is this requirement in place? I believe there are three types of hazards that require protection. The first is…
25.20: The conductors of the supply cord for type Y attachment and type Z attachment shall be insulated from accessible metal parts by basic insulation for class 0 appliances, class 0I appliances and class I appliances, and by supplementary insulation for class II appliances. This insulation may be provided by the sheath of the supply…
There is a requirement in clause 22.12 – the last paragraph as below: If the part is removed and can be contained within the small parts cylinder in Figure 13, its loosening is considered to result in a choking hazard. Actual photos are as follows： The standard is concerned that if parts are too small,…
protective device: device, the operation of which prevents a hazardous situation under abnormal operation conditions The standard emphasizes “abnormal operation” here. Only devices that operate under “abnormal operation” conditions can be defined as protective devices. Therefore, there are many types of protective devices, including overheating protection devices, overcurrent protection devices, and overpressure protection devices. Overheating…
non-self-resetting-thermal cut-out: thermal cut-out that requires a manual operation for resetting, or replacement of a part, in order to restore the current.NOTE Manual operation includes disconnection of the appliance from the supply mains. The thermal cut-out is equipped with a temperature-sensitive component, typically a bimetallic strip or a thermistor, which reacts to heat. As the…
thermal link: thermal cut-out which operates only once and requires partial or complete replacement It is a temperature sensing device, but it can only be operated once, when the temperature is higher than its set value, it will disconnect, and after disconnection, the current can not pass through, so as to play the role of…
self-resetting thermal cut-out: thermal cut-out that automatically restores the current after the relevant part of the appliance has cooled down sufficiently In the definition there is a clear mention, when the temperature is cooled to a certain degree, in fact, its intention is to control the temperature is not too high, when the temperature is…
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