Film capacitors – Power Factor Correction

B25836B4337A305

MKV capacitors

MKV440-D-20-02

Preliminary data

FK PC OH RD

September 2008

Please read Cautions and warnings and

Page 7 of 9

Important notes at the end of this document

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Overpressure disconnector

To ensure full functionality of an overpressure disconnector, the following must be observed:

1. The elastic elements must not be hindered, i.e.

- connecting lines must be flexible leads (cables),

- there must be sufficient space (min. 12 mm) for expansion above the connections. This will

enable a longitudinal extension of the can to secure the overpressure disconnector work.

- folding beads must not be retained by clamps.

2. Maximum allowed fault current of 10000 A in accordance with UL 810 standard must be assured by

the application.

3. Stress parameters of the capacitor must be within the IEC 60831 specification.

Overcurrent and short circuit protection

Use HRC fuses or MCCBs for short circuit protection. Short circuit protection and connecting

cables should be selected so that 1.5 times the rated capacitor current can be permanently

handled.

HRC fuses do not protect a capacitor against overload

- they are only for short circuit protection.

The HRC fuse rating should be 1.6 to 1.8 times rated capacitor current.

Do not use HRC fuses to switch capacitors (risk of arcing).

Use thermal magnetic over current relays for overload protection.

Resonance cases

Resonance cases must be avoided by appropriate application design in any case. Maximum total

RMS capacitor current (incl. fundamental harmonic current) specified in technical data must not be

exceeded.

Re-switching vs. phase-opposition

In case of voltage interruption, a sufficient discharge time has to be ensured to avoid phase-

Vibration resistance

The resistance to vibration of capacitors corresponds to IEC 68, part 2–6.

Max. test conditions:

Test duration

6 h*

Frequency range 1

10 ... 55 Hz*

Displacement amplitude

0.75 mm*

*corresponding to max. 98.1 m/s” or 10 g