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 done 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 ground wire is more complicated. The fact that it is connected to the correct contact does not yet prove its performance. The article will look at how to check the grounding in the outlet using various tools.
Colour marking of cable cores
Earlier, all the wires were of the same color, which led to the complication of wiring. Now the cores are marked with different colors. This is very convenient, especially when you have to pull a three-phase line. Neutral wires are always painted blue or cyan, more shades are allocated for phase wires: orange, red, black, gray, purple. In some brands of cables, all cores are white,however, in this case, a thin strip of the corresponding color runs along them.
What color is the ground wire? It is impossible to confuse him with others. Most often it is a bright yellow core with a green stripe or vice versa. Less often, a monochromatic yellow or green color is used. Surprisingly, the ground loop buses running along buildings, structures and structures are painted only black. This is accepted because the gas line is painted yellow.
Algorithm of actions for checking grounding
Not everyone attaches due importance to such protection, although it can save a life at some point. Before you check the grounding in the outlet, you should prepare certain tools and materials. For work you will need:
- Regular and indicator screwdriver;
- piece of wire, 20-30 cm long with stripped ends;
- multimeter.
There are several ways to check, some of which will be discussed now.
Step 1: visual inspection
The first thing to do is to make sure that there is a ground bus in the switch cabinet, after which, without turning off the voltage, you need to alternately touch the tip of the indicator screwdriver to all three pins of the socket. The control lamp in the housing should only light up when connected to the phase.
After, remembering the location of the zero contact, you need to turn off the introductory machine. You need to make sure again that there is novoltage, after which you can remove the decorative cover of the socket. Now it is clearly visible whether the corresponding wire is connected to the grounding contact (what color of the grounding wire is already known) and whether a jumper is installed from the neutral to it. Quite often, "craftsmen" try, using zeroing, to protect themselves, which is completely unacceptable. If the yellow-green wire is connected correctly, the socket can be closed and power on, proceed to the following steps.
Step 2: Check with indicator screwdriver and wire
All subsequent actions are performed with the voltage 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 seek help from professional electricians.
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, you need to do a minimum of actions. A piece of wire connects the previously noted zero contact to the grounding bracket. If everything is functioning properly, 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 grounding bracket. If the indicator lights up, then the wire is connected, but not the fact that it is not neutral. You will need a multimeter to check this.
Step 3: Use an optionalequipment
Let's figure out how to check the presence of grounding in the socket with a multimeter. Voltage is also required for testing. The tester switch is set to 600, 700, or 750 VAC. One of the probes is connected to the phase contact, the second in turn to the neutral and the grounding bracket. The readings that are displayed on the multimeter display must be compared. If they are ideally the same, 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 will be a long and painstaking work to find the twist.
Ideally, the voltage readings between zero and phase should be different. This happens because it is impossible to make a ground loop with parameters completely similar to zero. However, conclusions should not be drawn on the basis of a single test. It makes sense to check all sockets with grounding contacts that are located in an apartment or house. As a sample, you can first measure the voltage in the switch cabinet. If there is a difference between the contacts "earth / phase" and "neutral / phase" in the shield, it must be on the sockets.
Conclusion
Protective grounding is one of the most important moments in organizing the security of a home electrical network. It is it at a certain moment that can save the life of those living in the house. Having figured out how to check the grounding in sockets, the home master takes the first step towards a calm and comfortable life. The next step should be to install a protectiveautomation in case of its absence. It is not worth saving on this - in the event of an emergency, everything can cost much more.
