This section specifies the terms and definitions, technical requirements, and tests for various types of RCBO. This section applies to residual current operated circuit breakers (RCBOs) with overcurrent protection for household or similar purposes, with AC rated frequencies of 50 Hz, 60 Hz, or 50/60 Hz, rated voltage not exceeding 440 V, rated current not exceeding 125A, rated short-circuit capacity not exceeding 25000 A (at 50 Hz or 60 Hz), and operating functions unrelated to or related to the power supply voltage. RCBO is used for indirect contact protection of people, and the exposed conductive parts of the equipment should be connected to a suitable grounding electrode. RCBO can also be used for overcurrent protection of buildings and similar line equipment, and can also provide protection against fire hazards caused by continuous ground fault currents due to the failure of overcurrent protection devices. RCBO with a rated residual operating current not exceeding 30 mA can also be used as a supplementary protection measure when other electric shock protection measures fail. 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 this value. This device can also be connected, carried, and disconnected under specified conditions. Note 1: The content related to operating under residual current conditions in this section is based on GB 16916.1. The content related to overcurrent protection in this section is based on GB 10963.1. Note 2: RCBO is mainly used by non professional personnel and does not require maintenance. RCBO can be used to submit authentication. Note 3: The installation and usage regulations for RCBO are specified in GB 16895. RCBO is expected to be used in environments with pollution level 2. Note 4: For more severe overvoltage conditions, circuit breakers that comply with other standards (such as GB 14048.2) should be used. Note 5: For environments with higher pollution levels, enclosures with appropriate protection levels should be used. General RCBO 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 RCBO has sufficient resistance to false tripping even when surge voltage causes flashover and generates continuous current. Note 6: Surge absorbers installed behind general RCBOs and connected in a common mode may cause false tripping. RCBO is suitable for isolation purposes. Except for RCBOs with non interruptible neutral wires, RCBOs 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 GB16895.12). Note 7: For RCBOs with a protection level higher than IP20, special structures may be required. This section also applies to RCBOs assembled from suitable residual current devices and circuit breakers, whose mechanical assembly can be completed by the manufacturer in the factory or on-site. In this case, the requirements of Appendix G apply. RCBOs with more than one rated current are also applicable to RCBOs with several rated currents, as long as the device that converts the rated current from one value to another during normal use is inaccessible and cannot change the rated value without the use of tools. Additional technical requirements are required for plug-in RCBO. Special technical requirements must be attached to RCBOs installed in household and similar general purpose plugs, sockets, or appliance connectors, or RCBOs specifically used in combination with them, as well as frequencies expected to be used beyond 50 Hz or 60 Hz