Film capacitors – Power Factor Correction
PhaseCap MKK capacitors
B25667B2457A175
MKK230-I-7.5-01
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. The 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 IEC60831 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-
opposition and resulting high inrush currents.
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
These figures apply to the capacitor alone. Because the fixing and the terminals may influence the
vibration properties, it is necessary to check stability when a capacitor is built in and exposed to
vibration. Irrespective of this, you are advised not to locate capacitors where vibration amplitude
reaches the maximum in strongly vibrating equipment.
FK PC PM PFC
April 2008
Please read Cautions and warnings and
Important notes at the end of this document.
Page 6 of 8
EPCOS [ EPCOS ]
