(Peak) making current:
The peak value of the first major loop of the current in one pole of a
switching device during the transient period following the initiation of current during a
The peak value of the first major loop of current during the transient period
Current in one pole of a switching device at the instant of initiation of
an arc during a breaking process.
Value of the prospective breaking current that a circuit-breaker or load switch can break at a given voltage under prescribed conditions for application
and performance; e.g. overhead line (charging current) breaking capacity.
Short circuit on an overhead line at a short but not negligible distance
from the terminals of the circuit-breaker.
Out of phase (making or breaking) capacity:
Making or breaking capacity for which the specified conditions for use and behavior include the loss or the lack of synchronism between the parts of an electrical system on either side of the circuit breaker.
The voltage between the terminals of a circuit-breaker pole immediately
before making the current.
Voltage occurring between the terminals of a circuit-breaker pole
after interruption of the current.
The interval of time between application of the auxiliary power to the opening release of a switching device and the separation of the contacts in all three
The interval of time between application of the auxiliary power to the closing circuit of a switching device and the contact touch in all poles.
interval of time between the beginning of the opening time of a switching
device and the end of the arcing time.
the interval of time between application of the auxiliary power to the closing circuit of a switching device and the instant in which the current begins to flow in the
value of a characteristic quantity used to define the operating conditions
for which a switching device is designed and built and which must be verified by the
Rated normal current:
the current that the main circuit of a switching device can
continuously carry under specified conditions for use and behaviour. See below for
Rated short-time withstand current:
current that a switching device in a closed position can carry during a specified short time under prescribed conditions for use and behaviour. See below for standardized values.
The upper limit of the highest voltage of the network for which a switching device is rated. See below for standardized values.