Siemens SIVACON User Manual

Overpressure disconnector
6
Electrical components do not have unlimited life expectancies; this also applies to self-healing
capacitors. As polypropylene-type capacitors seldom produce a pronounced short circuit, HRC
fuses or circuit breakers alone do not o󹪜er su󹪟cient protection.
All capacitors of the PhaseCap Premium, PhaseCap Compact, PhaseCap Energy+, PhaseCap HD,
DeltaCap and PhiCap series are consequently 󹪝tted with a disconnector that responds to
overpressure. If numerous electric breakdowns occur at the end of life or as the result of thermal
or electric overload (within IEC 60831 speci󹪝cation), the formation of gas causes the pressure
inside the capacitor case to rise.
This causes a change in length because of curvature of the lid or stretching of the expansion
bead. Expansion beyond a certain degree will separate the internal wires (tear-o󹪜 fuses) and
disconnect the capacitor from the line.
CAUTION
The function of an overpressure disconnector can be a󹪜ected.
To ensure full functionality of an overpressure disconnector, observe the following
requirements:
1. The elastic metal top must not be impaired.
• The connecting lines must be 󹪞exible leads (cables).
• There must be su󹪟cient space for expansion above the connections (stated for the
di󹪜erent models).
• The folding groove must not be retained by clamps.
2. The maximum allowed fault current of 10000 A to the UL 810-standard must not be
exceeded.
3. Stress parameters of the capacitor must be within the IEC 60831speci󹪝cation.
Installation and maintenance instructions for Power Factor Correction (PFC) capacitors
Installation Manual, 05/2022, L1V30884033A 25

Siemens SIVACON Specifications

General

Type	Low-voltage switchgear and controlgear assembly
Modular design	Yes
Form of internal separation	Up to Form 4b
Standards	IEC 61439-1/-2
Installation type	Fixed or withdrawable