Differences are as follows:
①Current capacity is different, generally the first level in the overcurrent capacity is much larger than the second level, the first level is mainly used for current relief, the second level is mainly used for limiting the pressure, the people who have done the impact test know that, after the first level of current relief, and then after the second level of current limitation, the residual voltage becomes obviously very low.
②Response time is different, generally the first level of SPD if the switching type, the response time switching type than the pressure-limiting type to slow.
③Of course the level of protection will be different. Now the development and improvement of lightning protection, the previous use of multi-level protection, layers of pressure-limiting ways and means, now at a level that can meet the requirements.
Knowledge extension:
Surge, also known as the surge, as the name suggests, is beyond the normal operating voltage instantaneous overvoltage. Surge protection Device (Surge protection Device, referred to as SPD), also known as lightning protection, lightning arrester, is a variety of electronic equipment, instrumentation, communication lines to provide safety protection of electronic devices. Suitable for AC 50/60HZ, rated voltage to 380V power supply system (or communication system), the indirect lightning and direct lightning effects or other transient overvoltage surge protection, applicable to family homes, tertiary and industrial areas of the surge protection requirements, with relative phase, relative ground, relative to the center line, the center line to ground and its combination of protection modes.