When moving to a new apartment or buying a house in the private sector, you can never be sure that the installation of power networks in the premises is carried out properly. And if the switching of phase and neutral wires can be checked visually and practically by turning on, for example, a lamp, then the situation with the grounding wire is more complicated. The fact that it is connected to the desired contact does not yet prove its operability. The article will discuss how to check the grounding in the outlet using various tools.
Color coding of cable cores
Previously, all wires were monophonic, which led to a complication of wiring. Now the veins are marked with various colors. This is very convenient, especially when you have to pull a three-phase line. Neutral wires are always painted in blue or blue color, more shades are highlighted for phase: orange, red, black, gray, purple. In some brands of cables, all conductors are white, however, in this case there is a thin strip of the corresponding color along them.
And what color is the ground wire? It is impossible to confuse it with others. Most often it is a bright yellow vein with a green stripe or vice versa. Less commonly used is a plain yellow or green color. Surprisingly, the ground loop tires running along buildings, structures and structures are painted only in black. This is customary because the gas line turns yellow.
Algorithm for grounding verification
Not everyone gives due weight to such protection, although it can at some point save a life. Before checking the grounding in the outlet, it is necessary to prepare a certain tool and materials. For work you will need:
- ordinary and indicator screwdriver;
- a piece of wire, 20-30 cm long with stripped ends;
- multimeter.
There are several verification methods, some of which will now be considered.
Step # 1: visual inspection
The first thing to do is to make sure that there is a ground bus in the control cabinet, after which, without turning off the voltage, you need to alternately touch the tip of the screwdriver-indicator to all three contacts of the socket. The indicator light in the housing should only light when connected to a phase.
After, remembering the location of the zero contact, you need to turn off the input machine. Once again, make sure that there is no voltage, after which you can remove the decorative cover of the outlet. Now it is clearly visible whether the corresponding wire is connected to the grounding contact (what color the grounding wire is already known) and whether the jumper from the neutral is installed on it. Quite often, the "craftsmen" try, using zeroing, to protect themselves, which is completely unacceptable. If the yellow-green wire is connected correctly, the outlet can be closed and after applying voltage, proceed to the next steps.
Step # 2: check with an indicator screwdriver and wire
All subsequent actions are performed when the voltage is on, which requires utmost care and accuracy. If the home master is afraid of electricity or is not confident in his abilities, it is better to turn to professional electricians for help.
The easiest way to check the grounding in the outlet will be the option in which an RCD is installed in the switchboard. In this case, a minimum of actions is required. A piece of wire connects the previously noted zero contact to the ground bracket. If everything functions as expected, the RCD will trip.
Another option would be to use an indicator. It is inserted into the phase socket, and its contact pad is connected by a wire to the ground bracket. If the indicator lights up, it means that the wire is connected, but it is not a fact that it is not neutral. To check this, you need a multimeter.
Step number 3: use of additional equipment
We will figure out how to check the presence of grounding in the socket with a multimeter. To check, voltage is also required. The tester switch is set to 600, 700, or 750 VAC. One of the probes is connected to the phase contact, the second alternately with the neutral and the ground bracket. The readings that are displayed in this case on the display of the multimeter must be compared. If they are ideally identical, then there is reason to think. Most likely, the ground wire, if this is not visible in the input shield, is connected to the neutral in one of the junction boxes. In this case, there is a long and painstaking work to find twisting.
Ideally, the voltage reading between zero and phase should be different. This happens because it is not possible to carry out a ground loop with parameters completely similar to zero. However, based on one check, conclusions should not be drawn. It makes sense to check all sockets with grounding contacts that are located in the apartment or house. As a sample, you can first measure the voltage in the control cabinet. If there is a difference between the ground / phase and neutral / phase contacts in the shield, it must be on the outlets.
Conclusion
Protective grounding is one of the most important moments in organizing the safety of a home electrical network. It is precisely at a certain moment ”that can save the life of those living in the house. Having figured out how to check the grounding in outlets, the home master takes the first step to a calm and comfortable stay. The next should be the installation of protective automation in case of its absence. You should not save on this - in the event of an emergency, everything can be much more expensive.