How to distinguish between zero ground

I read the forum on the two speakers have some reason, if the connection is reversed, then disconnect the ground line which at least one has no electricity, no electricity naturally; another second floor said in the electrical appliances to determine the firewire after the operation of the clamp ammeter to measure the other two with the line's current, there is a current for the zero line is right. Because the ground current will trip, under normal circumstances, the ground is not current, even if there is a normal range of leakage current:

(1) hand-held electrical equipment for 15mA;

(2) environmentally hostile or humid places of electrical equipment for the 6 ~ 10mA;

(3) medical electrical equipment for 6mA;

(4) Building construction site electrical equipment for 15 to 30mA;

(5) household electrical circuit for 30mA;

(6) complete sets of switchgear distribution boards, etc. for 100mA;

(7) to prevent electrical fires for 300mA

Also want to ask you a question: can you close up immediately after the tripping, if you can not be connected to the reverse of the problem, because after the trip, to be followed by the use of electrical equipment. Because after the connection is reversed, to use the electricity behind the jump, jump after the electrical appliances are not off (not disconnected), then the same can not be closed up. So you have to be clear about this issue, if the jump can be closed up, it may be an instantaneous leakage, it may be leakage current is set too small, you can adjust (generally so large leakage protector can be adjusted), of course, there may be leakage protector quality problems (this is not easy to say, if you determine that it is not zero-ground connection is inverted, the leakage current is set to the maximum, and can be closed up immediately after jumping is the problem of it). (This is not easy to say).

So many users want to check or troublesome, if the jump after the close up, you can break the sub-switch to determine that a circuit has a problem, can not be closed is problematic, after disconnecting these sub-switches, there is no electricity since you will find you. Then start from their home, the user should also have a leakage protector, to jump should be the user leakage protector first jump ah.