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引用第1楼包子于2011-04-13 23:52发表的 :
0 F7 F5 v# A5 h$ e1 y' L对单相设备做法是将火线和地之间接一个10K可调电阻,调节电阻值使得GFCI动作,同时记录一下火线和零线的电流值作为参考,并记录火线和零线的不均衡电流(可能是AC,可能是DC也可能都有)
5 i# W; E6 A5 x u2 wA GFCI is much more subtle. When you look at a normal 120-volt outlet in the United States, there are two vertical slots and then a round hole centered below them. The left slot is slightly larger than the right. The left slot is called "neutral," the right slot is called "hot" and the hole below them is called "ground." If an appliance is working properly, all electricity that the appliance uses will flow from hot to neutral. A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second. , [0 c' _1 }' u: B7 E8 q. U4 W8 o+ c
包子,这个测试是不是有专门的仪器测的?? |
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