China Standard Classification (CCS): K31 International Standard Classification (ICS): 29.120.50 Release date: 2014 Implementation date: 2015-06-29 Page: 142 Standard status: Voided clicks: 519 Abolishment date: 2017-03-23 Scope of application: This section specifies the terms and definitions, technical requirements, and testing of various types of RCBO. This section applies to residual current operated circuit breakers (RCBOs) with overcurrent protection for household or similar applications, with AC rated frequencies of 50Hz, 60Hz, or 50/60Hz, rated voltage not exceeding 440V, rated current not exceeding 125A, rated short-circuit capacity not exceeding 25000A (at 50Hz or 60Hz), 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 30mA 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 connect, carry, and break overcurrent under specified conditions. General RCBO error resistant tripping refers to the negative current generated by surge voltage (generated by transient overvoltage or lightning induction during operation) in the equipment without flashover. S-type RCBO has sufficient resistance to false tripping even when surge voltage causes flashover and generates continuous current. 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 GB 16895.12). 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 the RCBO for plugs, sockets, or appliance connectors installed for household and similar general purposes, or specifically used in combination with them, as well as for frequencies expected to be used beyond 50 Hz or 60 Hz.