Film capacitors – Capacitors for Power Factor Correction
WindCap capacitors
B25668A6836A375
MKK690-D-12.5-11
Service life expectancy
Electrical components do not have an unlimited service life expectancy; this applies to self-healing
capacitors too. The maximum service life expectancy may vary depending on the application the
capacitor is used in.
Safety
Electrical or mechanical misapplication of capacitors may be hazardous. Personal injury or property
damage may result from bursting of the capacitor or from expulsion of oil or melted material due to
mechanical disruption of the capacitor.
Ensure good, effective grounding for capacitor enclosures.
Provide means of disconnecting and insulating a faulty component/bank.
The terminals of capacitors, connected bus bars and cables as well as other devices may also be
energized.
Follow good engineering practice.
Thermal load/over-temperature
After installation of the capacitor it is necessary to verify that maximum hot-spot temperature is not
exceeded at extreme service conditions.
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 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.
FK PFC R&D
July 2007
Page 5 of 8
EPCOS [ EPCOS ]
