Leakage Current Protection Requirements in the American Standard UL2231 (CCID-20)
The global electric vehicle industry is in a stage of rapid growth, especially in China, Europe, and North America. The sales and export volume of charging piles supporting electric vehicles are also rising year by year, which is a huge opportunity for domestic charging pile companies. Charging pile products need to be UL certified to enter the US market, and safety regulations need to comply with UL2594/UL2231-2 standards. This is also a technical challenge that major charging pile companies need to face. Complying with UL certification means that there will be no safety hazards, and it will also increase the brand credibility of the product.
Due to the huge differences between the power grid systems in North America and China, the standards for charging mode 2 (ICCPD) and charging mode 3 (AC Charger / Wall-Box) are completely different from the European standard (IEC61851, IEC62752 and IEC62955) and the Chinese national standard (GB/T 18487.1). The requirements for leakage current protection in the American standard (UL2231) are very different from those in the national standard (GB/T 18487.1) and the European standard (IEC61851, IEC62752 and IEC62955). This time, let's take a brief look at the requirements for leakage current protection in the American standard (UL2231).
The leakage protection types are mainly divided into CCID5 and CCID20. The leakage protection type is selected based on the voltage level, basic insulation, double insulation and reinforced insulation, whether it has a grounding monitoring function, and whether the neutral line is grounded. CCID5 or CCID20.
In simple terms, CCID5 has a protection range of 5±1mA for AC leakage and 30mA for DC. It also protects against DC+AC mixed leakage current and high frequency. CCID20 has a protection range of 15~20mA for AC leakage and 40X1.414=56.56mA for DC. It also protects against mixed leakage current and high frequency leakage. Similar to the B-type leakage protection in the European standard, it is necessary to protect against various complex leakages and also consider the hazards of DC leakage. However, it is very different from the European standard. We know that there is a DC 6mA protection requirement in the European standard, which is a requirement for magnetic protection to prevent DC leakage from causing DC bias magnetic effect on other devices in the charging system that perform leakage protection based on the principle of mutual inductance, thereby causing protection failure. The protection threshold of DC leakage in UL2231 is greater than that of AC. Obviously, the focus is on the direct damage caused by DC to the human body.
As a world-leading supplier of leakage current protection solutions, IVY Metering has found in some actual application cases that different certification agencies have different interpretations and testing methods for American standards. IVY can provide sensor-level American standard leakage current protection solutions to help customers complete the certification of American standard charging piles.
