15. PE（protective earth）和FE（functional earth）有什么区别

protective earth or circuit protective earth is intended to protect the personals from electric shock during an earth fault in any appliances he/she is using. This earth conductor will have a connection from appliances metalic exposed part up to the main earth terminal in the supply intake room. The fault current will flow through this conductor to the eart mass which will in turn on the protective devices such as MCB or RCD to safely open the circuit within 0.4 seconds.

Functional earth is intended to reduce the radio frequency noise, computer filters to enhance the clarity of signals or other equipments which have always 10mA leakage current. Functional earthing must be separated from installation earthing except at the main earth terminal connection point.


2019.12.18 朱元 编辑