DFK series capacitor with smart composite switching on-off switch (hereinafter referred to as the composite switch), it is mainly used for ac 50 hz - 60 hz rated voltage of 220 v or 380 v low voltage reactive power compensation connected and breaking power capacitors in the system. Its main characteristic is in no flow, no noise, stable and reliable with low consumption. Function characteristics: DFK compound switch is made up of three separate compound switch, is suitable for low voltage reactive power compensation capacitor group of on-off control. The basic working principle of composite switch is to keep SCR and magnetic relay and answered. Make the composite switch at the instant of the on and off has the advantages of thyristor zero for and during normal through has the advantages of the contactor switch without power.

1, zero cutting: the basic working principle of compound switch is to keep magnetic relay and thyristor switch, achieve zero current conduction and the zero voltage disconnect, made of composite switch in the on and off the moment has the advantage that the thyristor switch without inrush current, and during the normal connected and has the advantages of physical switch without power. Its implementation method is: when the input voltage zero moment control thyristor forerunner, stability and then keep magnetic relay and conduction; And removal is to keep the magnetic relay disconnect, silicon controlled delay zero disconnect, so as to realize zero current removal.

2, cutting and intelligent monitoring and controlled by single chip microcomputer, magnetic hold relay, and operation condition of the input power and load, which has perfect protection function:

Fault phase voltage protection: system voltage phase power supply, switch refused to close;

Supply voltage lacks protection: the working power supply when the power is lack of phase, switch refused to close;

Self-diagnosis fault protection: the system automatically monitor running state of thyristor, magnetic hold relay, if it fails, refused to close or exit automatically disconnect;

After connecting a power outage protection: meet a sudden power failure, automatic trip off.

3, no harmonic injection: due to conduction is triggered by thyristor zero moment, after a time delay is kept by magnetic relay and conduction, and won't produce harmonic relay work.

4, low consumption, the adoption of magnetic hold relay, control device in the cutting action only instantaneous power, no electricity at ordinary times; And as a result of the magnetic stick relay contact resistance is small, and therefore not fever, instead of plus heat sink or fan, reduces the cost. Can completely avoid silicon controlled burning phenomenon, at the same time also to be run on the same other appliances cause no harm, truly achieved the purpose of saving energy and reducing consumption.

5, the input signal and compound switch photoelectric isolation: strong anti-jamming capability, safe and reliable work.