Page 22 - ELECTRONICON_Katalog_PFC-60Hz

DEFINITIONS AND SELECTION CRITERIA

Rated Voltage U N
Root mean square of the max. permissible value of sinusoidal AC voltage in continuous operation. The rated voltage of the
capacitors indicated in the data charts must not be exceeded even in cases of malfunction. Bear in mind that capacitors in
DEFINITIONS AND SELECTION CRITERIA
detuned equipment are exposed to a higher voltage than that of the rated mains voltage; this is caused by the connection of
detuning reactor and capacitor in series. Consequently, capacitors used with reactors must have a voltage rating higher than
that of the regular mains voltage (compare U on page 55). Unless indicated otherwise, all voltages stated in this catalogue
C
are rms values.

Maximum RMS Voltage U max
Maximum rms voltage, which the capacitor can be exposed to permanently. This value also considers the maximum reactive
power and the resulting power losses of the capacitor.

Test Voltage Between Terminals U BB
Routine test of all capacitors conducted at room temperature, prior to delivery. A further test with 80 % of the test voltage
stated in the data sheet may be carried out once at the user‘s location.

Voltage test between terminals and case U BG
Routine test of all capacitors between short-circuited terminals and case, conducted at room temperature. May be repeated at
the user’s location.

Rated power Q C
Reactive power resulting from the ratings of capacitance, frequency, and voltage: Q = 2πf · C · U 2 N
C

Maximum RMS Current Rating I max
Maximum rms value of permissible current in continuous operation. The maximum permitted rms current for each particular
capacitor is related either to construction features or to the current limits of the terminals. In accordance with IEC 60831 all
ELECTRONICON capacitors are rated at least 1.3×I (with I being the nominal current of the capacitor at rated voltage and
N
N
frequency), allowing for the current rise from permissible voltage and capacitance tolerances as well as harmonic distortion.
As a rule, our values of maximum permitted continuous current are substantially higher. The exact value for each capacitor can
be found in the individual data sheet. Higher rms values can be implemented by adjustments in construction and are available
on request.
»!« Continuous currents that exceed the I values specified in the data charts will lead to a build-up of heat in the
max
capacitor and may cause reduced lifetime or premature failure. Permanent excess current may even result in
malfunction of the capacitor’s safety mechanisms, i.e. bursting or fire (see page 18).

Care must be taken not to exceed the maximum voltage and current ratings when installing capacitors in close-tuned or detuned
equipment (see data sheets for maximum ratings). The thermal monitoring of reactors, or the use of overcurrent protection re-
lays in the capacitor circuit is recommended to protect against overloads.

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