The safety capacitor is divided into x type and y type
Le condensateur de sécurité est divisé en deux types : le type x et le type y. L'alimentation en courant alternatif est divisée en 3 bornes : Fire L/Zero N/Ground, (L=Ligne, N=Neutre, G=Ground). Entre "L-N", c'est-à-dire "Fire-Zero", se trouve le condensateur X ; entre "L-G/N-G", c'est-à-dire "Fire-Ground" ou "Zero-Ground", se trouve le condensateur X. ou "Zero-Ground" se trouve entre le condensateur Y. Entre le fil de feu et la ligne zéro connectée à un condensateur de type "X", et entre le fil de feu et le fil de terre connecté à un condensateur de type "Y", il n'y a pas de différence entre les matériaux à diviser.
Safety standard capacitor
X capacitor: Because the location of this capacitor is also critical, it also needs to comply with the relevant safety standards, and X capacitor is also one of the safety capacitors. According to the actual needs, the capacitance of X capacitor is allowed to be larger than the capacitance of Y capacitor, but at this time, a safety resistor must be connected in parallel to both ends of X capacitor, which is used to prevent the power cord from being unplugged, due to the charging and discharging process of the capacitor and the power cord plug is charged for a long time. Safety standards, when the machine is working in the power cord is unplugged, in two seconds, the power cord plug voltage charged at both ends (or potential to ground) must be less than 30% of the original rated working voltage.
As one of the safety capacitors, X capacitor is also required to obtain the certification from the safety testing agency. X capacitor is generally marked with safety certification mark and withstand voltage AC250V or AC275V, but its real DC withstand voltage is up to 2000V or more, so don’t use ordinary capacitors with nominal withstand voltage AC250V or DC400V as a substitute.
Usually, the X capacitor uses the mylar film type capacitor with high ripple current. This type of capacitor is larger in size, but its instantaneous charging and discharging current is also large, and its internal resistance is smaller.
Y capacitors: The two Y capacitors are connected in critical positions and must comply with the relevant safety standards to prevent leakage from electronic devices or electrically charged cases, which can easily endanger personal safety and lives. They are safety capacitors, which require the capacitance value not to be large, and the withstand voltage must be high. Therefore, the total capacity of Y capacitor should not exceed 4700PF (472).
GJB151 stipulates that the capacity of Y capacitor should be no more than 0.1uF. In addition to conforming to the corresponding grid voltage withstand voltage, Y capacitors are required to have sufficient safety margin in electrical and mechanical performance to avoid The voltage withstand performance of Y capacitor is important to protect personal safety. Y capacitors are mostly orange or blue in appearance, and are generally marked with safety certification marks (such as UL, CSA, etc.) and withstand voltage of AC250V or AC275V. However, the true DC withstand voltage is up to 5000V or more. It must be emphasized that Y capacitors should not be used in place of ordinary capacitors with nominal withstand voltage of AC250V or DC400V.