This is to distinguish the power limiting system. Some intelligent power limiting systems can identify load types, that is, the restrictions on resistive loads are more serious, while the restrictions on other types of loads are wider. There are also some power limiting systems, which limit power regardless of the load type, and automatically cut off power when the power exceeds the standard.

The difference between resistive load and other types of loads is that the power factor of resistive load is 1 and the phase angle of voltage and current is 0, so the power limiting system can judge the load type accordingly.