This is exactly what the title of the question from the reader Dmitry sounded like.
I continue to publish the questions that readers asked me. For new dear readers who came to my channel for the first time, I inform you that this is already 18 such publication.
Consider in this 18th part a question from Dmitry:
Hello. We bought a new boiler, plugged it in, but the water shocks a little (when the boiler is plugged into the outlet), when it is turned off, nothing like that is observed. The old boiler sometimes gave it out too. Therefore, we doubt the operation of grounding. How can it be checked without the intervention of the master and is it necessary to check the circuit itself and the cable going to it for this?
I gave Dmitry the following answer within the limits of my knowledge and qualifications:
Dear Dmitry! You need to start with the fact that grounding, according to its definition, is an action, namely, the electrical connection of conductive parts to the local ground.
Therefore, if you focus on your question and answer it literally, then yes - you need to check all the electrical connections of the conductive parts of the boiler to the local ground.
But there are many unknowns in your question. For example, I do not know anything about how you generally performed the electrical installation of your individual residential building. What type of system grounding and so on ...
During the check, available at home, I can recommend you only the following basic measures:
- Perform a visual inspection - the purpose of this action is to identify a visible rupture or damage to any electrical circuits of protective conductors. As a rule, the visible open areas of the protective conductor, its connections and connections to the main grounding bus are subject to inspection. (GZSH) (you should have it if we are talking about the correct implementation of the grounding device) and then directly with the grounding itself device.
- It is necessary to check the grounding conductor, through which the GZSh is connected to the ground electrode;
- It is necessary to check the protective conductor, through which the protective bus of the input-distribution device (ASU) is connected to the GZSh. Again, if you have this lie, I do not know anything about it.
If there is no visible break, it is necessary to check for the "presence of a circuit" between the protective conductor (s) and the GSP. For "continuity", you just need to connect the multimeter leads, in the appropriate mode, to the protective conductor and to the main ground bus. You can also check the circuit between the protective conductor and the grounding device.
The most effective option, in my opinion, is to measure the contact resistance between the ground electrodes and the local ground. But for this you need a special device - a "ground resistance meter", which is connected in a certain way. But this work can only be done by a qualified or trained person - so I will not describe how to do it within the scope of this answer.
However, even with a spreading resistance of less than 4 ohms, there is no guarantee that you will be safe. Since no electrical devices must supply a dangerous potential to the housing under normal operating conditions. Therefore, in addition to checking the grounding device, I would recommend that you also check the insulation condition of the boiler itself. As a rule, damage or defect in insulation in the water heater itself or in its supply circuit can lead to the appearance of a potential on the body of the electric boiler.
Due to the fact that not every commentator or just a reader can sensibly understand the purpose and essence of my advice and my answers to specific questions from other readers, after each publication I will publish the following disclaimer (Disclaimer):
My information is just information for thought. Electrical work performed without skills and appropriate experience is very dangerous! The materials of the publication are only advisory in nature and are provided for informational purposes only. I am not responsible for the application of the information provided in real conditions!
For a detailed solution of the issue, you must definitely contact a qualified person who will come and solve your problem on the spot.
P.S. Dear Readers! If you have your own version of the answer to this question, then please write it in the comments. It will also be interesting for me to read it and, if necessary, discuss it.
P.S. Link to some past parts - Part 17, Part 16, Part 15, Part 14, Part 13.