The ability to switch between the AC and DC circuits is very different and the rating is confirmed. In the case of DC, the control capacity is very low. This is mainly because DC does not have a zero point (current zero crossing point) like AC, so it is difficult to eliminate the arc once it is generated, and the arc time is long. Moreover, the current direction does not change, so there is a phenomenon of contact migration, and the contact may not be broken due to unevenness, which may cause malfunction.
The constant current and surge current of some types of loads vary widely. It must be used within the range of allowable inrush current values. The greater the inrush current during closed circuit, the greater the consumption and migration of the contacts, and the failure of the contacts to switch due to the fusion and migration of the contacts. In the case of electric induction, a reverse induced voltage is generated. The higher the voltage, the greater the energy, and the consumption and migration of the contact increases. Therefore, the rated condition is confirmed, and the control capacity is indicated in the rated value, but These are not enough. In the special load circuit such as the voltage, current waveform, and type of load at the time of switching on and off, it is necessary to perform actual device test confirmation. For small voltages and currents, use a product with a small load. When using general-purpose silver contacts, contact reliability may be degraded. When the push button switch is out of the small and high load type of the button switch range, connect a relay suitable for the load.