BS IEC 62873-2:2016 pdf download – Residual current operated circuit-breakers for household and similar use Part 2: Residual current devices (RCDs) — Vocabulary
3.1.3
pulsating direct current
current of pulsating wave form which assumes, in each period of the rated power frequency,the value 0 during one single interval of time, expressed in angular measure, of at least 180R*
Note 1 to entry: The adjective “pulsating” is defined in lEC 60050-103:2009,103-06-07.
3.1.4
current delay anglea
time，expressed in angular measure， by which the starting instant of current conduction isdelayed by phase control
[SOURCE: IEC 60050-442:1998,442-05-42,modified – ln the definition,”the phase anglerepresenting the time” has been replaced by “time, expressed in angular measure,”.]
3.1.5
smooth direct current
direct current which is ripple free
Note 1 to entry: A current is considered to be ripple free when the coefficient of ripple is below 10 %.3.2Definitions relating to the energization of an RCD
3.2.1
energizing quantity
electrical excitation quantity which，alone or in combination with other such quantities，isapplied to an RCD to enable it to accomplish its function under specified conditions
3.2.2
energizing input-quantity
energizing quantity by which the RCD is activated when it is applied under specifiedconditions
Note 1 to entry: These conditions involve, for example, the energizing of certain auxiliary elements.3.2.3
residual currentIA
r.m.s. value of the vector sum of the instantaneous values of the currents flowing through themain circuit of the RCD
[SOURCE: IEC 60050-442:1998,442-05-19，modified – “of the instantaneous values” hasbeen inserted.]
3.2.4
residual operating currentIAn
value of residual current which causes the RCD to operate under specified conditions
[SOuRCE: lEC 60050-442:1998,442-05-20]
3.2.5
residual non-operating currentIAno
value of residual current at which (and below which) the RCD does not operate underspecified conditions
[SOURCE: IEC 60050-442:1998,442-05-21]
3.2.6
residual currentIAt
<of an RCBO> value of residual current which is the lower limit of the overcurrentinstantaneous tripping range
3.3Definitions relating to the operation and functions of an RCD
3.3.1
switching device
device designed to make or break the current in one or more electric circuits
[SoURCE: IEC 60050-441:2000,441-14-01]
3.3.2
mechanical switching device
switching device designed to close and open one or more electric circuits by means ofseparable contacts
[SOURCE IEC 60050-441:2000,441-14-02,modified – Note has been deleted.]
3.3.3
circuit-breaker
mechanical switching device,capable of making, carrying and breaking currents under normalcircuit conditions and also making,carrying for a specified duration and breaking currentsunder specified abnormal circuit conditions such as those of short-circuit
[SoURCE: IEC 60050-441:2000,441-14-20]
3.3.4
fuse
a device that by the fusing of one or more of its specially designed and proportionedcomponents，opens the circuit in which it is inserted by breaking the current when thisexceeds a given value for a sufficient time.The fuse comprises all the parts that form thecomplete device
[soURCE:IEC 60050-441:2000,441-18-O1]
3.3.5
residual current deviceRCD
mechanical switching device or association of devices designed to make，carry and breakcurrents under normal service conditions and to cause the opening of the contacts when theresidual current attains a given value under specified conditions
3.3.6
detection
<of a residual current device> function consisting in sensing the presence of a residual current
Note 1 to entry: This function can be performed, for example, by a transformer integrating the vector sum of the currents.
[SOURCE: IEC 60050-442:1 998, 442-05-24]
3.3.7
evaluation
<of a residual current device> function consisting in giving to the residual current device the possibility to operate, when the detected residual current exceeds a specified reference value
[SOURCE: IEC 60050-442:1 998, 442-05-25]
3.3.8
interruption
<for a residual current device> function consisting in bringing automatically the main contacts of the residual current device from the closed position into the open position, thereby
interrupting the current(s) flowing through them [SOURCE: IEC 60050-442:1 998, 442-05-26]
3.3.9
r.c. unit
device performing simultaneously the functions of detection of the residual current and of comparison of the value of this current with the residual operating value, and incorporating
the means of operating the tripping mechanism of a circuit-breaker with which it is designed to be assembled or associated
3.3.1 0
residual current operated circuit-breaker without integral overcurrent protection
RCCB
residual current operated circuit-breaker not designed to perform the functions of protection against overloads and/or short circuits
[SOURCE: IEC 60050-442:1 998, 442-05-03, modified – “switching device” has been replaced by “circuit-breaker”.]