How a multimeter detects if it's shorted or grounded
But I still according to no circuit breaker and leakage circuit breaker protection under the gate switch distribution line how to detect a short circuit or ground to answer the question; (in fact, the gate switch distribution if there is a short circuit phenomenon on the line, then; the consequences of its either burned off the conductor is burned out of the gate switch, nonetheless; I'm still according to the principle of detection to answer the question).
(1) the power distribution line at the beginning of the power switch off, all the load switch on the line disconnected, including plugged in the socket plug load separation, with a multimeter resistance × 100 gear measurement of the power switch out of the end of the two wires out of the resistance, if it is measured to the multimeter resistance is very small (i.e., the pointer to the right swing almost the end of the end), then prove that there is a short-circuit phenomenon between the phase line and the zero line, or else it is not a short-circuit. Otherwise, there is no short circuit. The same test method to measure the phase line to the protective ground (zero) line, zero line to the protective ground (zero) line whether there is a short-circuit phenomenon.
(2) If you exclude the phase line to the zero line, phase line to the protective grounding (zero) line, zero line to the protective grounding (zero) line no short-circuit phenomenon, you can test the phase line and the zero line whether the grounding phenomenon.
Detect grounding if you have a clamp meter on hand is best to use a clamp meter to detect grounding current. Detection method is: first disconnect the power switch, the distribution of zero line from the power switch from the end of the line removed (and mark), and then close the power switch, with a clamp meter clamp measurement of the phase line with or without grounding current (clamp meter first dialled to the 100A file such as the current can not be detected and then slowly dialled to the smaller current level) if still not measured grounding current; can be excluded from the phase line grounding. After testing the phase line, disconnect the power switch to remove the phase line, connect the zero line to the power switch on the phase line out of the contact point, close the power switch with the above clamp meter to measure the phase line method of testing the zero line.
If there is no clamp meter at hand; you can also find a chandelier head with about 25 watts of incandescent bulbs and install the head, connected to two 15 cm or so of wire backup. Detection method is; disconnect the power switch, remove the phase line and zero line, first of all, the lamp head and bulb series in the phase line and power switch between the phase line out of the contact point, do a good job of safety measures, close the power switch, at this time, if the bulb is bright to prove that there is a grounding phenomenon of the phase line, the higher the brightness of the bulb grounding current will be bigger, and vice versa, the smaller the grounding current, if the bulb does not light up to rule out the grounding of phase line. After testing the phase line, disconnect the power switch, remove the phase line, the original bulb in series in the zero line and the power switch out between the phase line junction, but also do a good job of safety measures, close the power switch to detect the zero line, the test results are the same as the above detection of the phase line.
