This part of GB 16916 specifies the terms and definitions, technical requirements, and tests for various types of RCCB. This section applies to residual current operated circuit breakers (RCCBs) without overcurrent protection for household and similar purposes, with an AC rated frequency of 50 Hz. 60 Hz or 50/60 Hz, a rated voltage not exceeding 440 V, a rated current not exceeding 125A, and an action function unrelated to or related to the power supply voltage. RCCB is used for indirect contact protection of people, and the exposed conductive parts of the equipment should be connected to a suitable grounding electrode. They can also provide protection against fire hazards caused by continuous ground fault currents due to the failure of overcurrent protection devices. RCCB with a rated residual operating current not exceeding 30 mA can also be used as a supplementary protection measure in case of failure of other electric shock protection measures. This section is applicable to devices that can simultaneously detect residual current, compare the residual current value with the residual action current value, and disconnect the protected circuit when the residual current exceeds the residual action current value. Note 1. The technical requirements of RCCB comply with the general requirements of GB/Z6829, mainly for use by non professional personnel, and do not require maintenance. RCCB can be used to submit certification. Note 2: The installation and use regulations for RCCB are specified in GB 16895, and RCCB is expected to be used in environments with pollution level 2. RCCB is suitable for isolation purposes. Except for RCCBs with non interruptible neutral wires, RCCBs that comply with this section are applicable to IT systems. When excessive overvoltage is prone to occur on the power supply side (such as when the power supply is introduced through overhead lines), special protective measures can be taken (such as using lightning arresters) (see GB 16895.12). General RCCB error resistant tripping refers to the generation of load current in the equipment without flashover due to surge voltage (generated by transient overvoltage or lightning induction during operation). S-type RCCB has sufficient ability to withstand false tripping even when surge voltage causes flashover and generates continuous current. Note 3: Surge absorbers installed behind general RCCBs and connected in a common mode may cause false tripping. Note 4: For RCCBs with a protection level higher than IP20, special structures may be required. The following products must be supplemented with special requirements: - Residual current operated circuit breakers with overcurrent protection (see GB 16917.1)—— RCCB or RCCB specifically designed for use in conjunction with plugs, sockets, or appliance connectors for household and similar general purposes-- And RCCB expected to be used in frequencies other than 50Hz or 60Hz. For RCCBs installed in sockets or specifically assembled with sockets, the technical requirements of this section can be used in conjunction with GB 2099.1 or the relevant requirements of the country where the product is placed on the market (when applicable). Note 5: For RCCBs installed in sockets or specifically assembled with sockets, they can comply with GB 28527-2012 or this part. The technical requirements of this section are applicable to normal environmental conditions (see 7.1). For RCCBs used in harsh conditions, necessary technical requirements can be supplemented. RCCB using batteries is not included in the scope of this section