Page 179 - 1SBC104119C0202_MainCatalog_R contactors

Terms and technical definitions

Terminology Rated breaking or making capacity

Altitude Root mean square value (R.M.S.) Of the current that the contactor is
able to break or make at a given voltage according to the conditions
Characterizes the place of use. It is expressed in metres above sea specified by standards and for a given utilization category.
level.

Circuits Ambient temperature
–– Auxiliary circuit:
Air temperature close to the contactor.
All the conductive parts of a contactor designed to be inserted in
a different circuit from the main circuit and the contactor control Time
circuits. –– Time constant :
–– Control circuit:
All the conductive parts of a contactor (other than the main circuit Ratio of the inductance to the resistance (L/R = mh/Ω = ms).
and the auxiliary circuit) used to control the contactor's closing op- –– Short-time withstand current Icw:
eration or opening operation or both.
–– Main circuit: Current that the contactor is able to withstand in closed position for
All the conductive parts of a contactor designed to be inserted in the a short time interval and in specified conditions.
circuit that it controls. –– Minimum switching time:
This is the minimum closing or opening order time necessary for the
Rated operational current Ie contactor to reach complete closing or opening.
–– Closing time:
Current rated by the manufacturer. It is mainly based on the rated Time interval between the beginning of the closing operation and the
operational voltage Ue, the rated frequency, the utilization category, the instant the contacts touch on all the poles.
rated duty and the type of protective enclosure, if necessary. –– Opening time:
Time interval between the specified starting instant of the opening
Conventional free air thermal current Ith operation and the instant the arcing contacts separate on all the
poles.
Current that the contactor can withstand in free air for a duty time of
8 hours without the temperature rise of its various parts exceeding the Rated control voltage Uc
maximum values given by the standard.
Control voltage value for which the control circuit is sized.

Electrical durability Rated operational voltage Ue

Number of on-load operating cycles that the contactor is able to carry Voltage to which the contactor's utilization characteristics refer. In
out. It depends on the utilization category. three-phase it is the phase-to-phase voltage.

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Mechanical durability Rated insulation voltage Ui
Number of no-current operating cycles that a contactor is able to carry Reference voltage for dielectric tests and creepage distances.
out.
Rated impulse withstand voltage Uimp
Switching frequency Peak value of an impulse voltage, having a specified form and polarity,
Number of switching cycles per hour. which does not cause breakdown in specific test conditions.

Coil operating limits Shock withstand
Expressed in multiples of the nominal control circuit voltage Uc for the Requirement for vehicles, crane drives, installations on board ships and
upper and lower limits. plug-in equipment. The contactors must not change position and the
overload relays must not trip.
Mounting position
Comply with the manufacturer's instructions. Resistance to vibrations
Requirements for vehicles, boats and other means of transport. For
the specified vibration amplitude and frequency values the device must
remain able to operate.

1SBC104079S0201

ABB R contactors | 10/3