Page 17 - ELECTRONICON_Katalog_PFC-60Hz

SAFE OPERATION

Protection against Overvoltages and Short Circuits: Self-Healing Dielectric
All dielectric structures used in our power capacitors are “self-healing”: In the event of a voltage breakdown the metal layers
around the breakdown channel are evaporated by the temperature of the electric arc that forms between the electrodes. They
are removed within a few microseconds and pushed apart by the pressure generated in the centre of the breakdown spot. An
insulation area is formed which is reliably resistive and voltage proof for all operating requirements of the capacitor. The capa-
citor remains fully functional during and after the breakdown.

For voltages within the permitted testing and operating limits the capacitors are short-circuit- and overvoltage proof. They are also
proof against external short circuits as far as the resulting surge discharges do not exceed the specified surge current limits.

Self-healing
SAFE OPERATION
breakdown

pic.3

Protection Against Accidental Contact
All capacitors are checked by routine test (voltage test between shorted terminations and case: U > 2 U + 2000 V, at least 3000V)
BG
N
in accordance with IEC 60831. Accessible capacitors must be earthed at the bottom stud or with an additional earthing clamp.
The CAPAGRIP™ terminal blocks are rated IP20, i.e. they are protected against accidental finger contact with live parts. The
discharge modules are designed in the same way (compare page 45). Unused contact cages of design M terminal blocks must be
covered by a proper blank (available as standard accessory, see page 49).

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