BS IEC 62873-2:2016 pdf free download – Residual current operated circuit-breakers for household and similar use
3.3.27 RCD type A
RCD for which tripping is ensured for residual sinusoidal alternating currents and residual pulsating direct currents, whether suddenly applied or slowly rising, and in addition for residual pulsating direct currents superimposed on smooth direct current up to 6 mA
3.3.28 RCD type F
residual current device for which tripping is ensured as for type A as applicable, and in addition:
– for composite residual currents, whether suddenly applied or slowly rising intended for circuit supplied between phase and neutral or phase and earthed middle conductor;
– for residual pulsating direct currents superimposed on smooth direct current up to 1 0 mA Note 1 to entry: The tripping for type A is according to IEC 61 008-1 or IEC 61 009-1 .
3.3.29 RCD type B
residual current device for which tripping is ensured as for type F and in addition:
– for residual sinusoidal alternating currents up to 1 000 Hz;
– for residual alternating currents superimposed on a smooth direct current equal to 0,4 I ∆n or 1 0 mA, whichever is the higher value;
– for residual pulsating direct currents superimposed on a smooth direct current;
– for residual pulsating rectified direct current which results from two or more phases;
– for residual smooth direct currents whether suddenly applied or slowly increased independent of polarity
3.3.30 test device
device incorporated in the RCD simulating the residual current conditions for the operation of the RCD under specified conditions
3.4.3 limiting value of the non-operating current in case of single phase overcurrent
maximum value of single phase overcurrent which, in the absence of a residual current, can flow through an RCD (whatever the number of poles) without causing it to operate Note 1 to entry: In the case of overcurrent in the main circuit, in the absence of residual current, operation of the detecting device may occur as a consequence of asymmetry existing in the detecting device itself.
3.4.4 overload current
overcurrent occurring in an electrically undamaged circuit
Note 1 to entry: An overload current may cause damage if sustained for a sufficient time.
3.4.5 short-circuit current
overcurrent resulting from a fault of negligible impedance between points intended to be at different potentials in normal service
Note 1 to entry: A short-circuit current could result from a fault or from an incorrect connection.
3.4.6 residual short-circuit withstand current
maximum value of the residual current for which the operation of the RCCB is ensured under specified conditions and above which the device may undergo irreversible alterations
3.4.7 prospective current
current that would flow in the circuit, if each main current path of the RCD and of the overcurrent protective device, if any, were replaced by a conductor of negligible impedance
Note 1 to entry: The prospective current can be qualified in the same manner as an actual current, for example:prospective breaking current, prospective peak current, prospective residual current, etc.
[SOURCE: IEC 60050-442:1 998, 442-01 -47, modified – In the definition, “switching device” has been replaced by “RCD”.]