Can I ground the washing machine from the bathroom?
Is it possible to ground the washing machine to the bath ground panel? Under the bath there is a plastic shield to which there is a wire connected to the bath, is it possible to ground the washing machine to this wire?
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It is possible, but not quite as you write. Put the PMC - this is a type of distribution box with only a bus inside, connect the ground wire to it, which goes to the bathroom. And already from this bus you connect separately a bathroom and a washer. We considered a similar question in more detail in the article.
Although if I correctly presented your situation, then maybe this is the plastic shield that you have installed. What is inside it? If what I wrote above, then you can connect the grounding of your washing machine there - everything should be fine!