{"id":53211,"date":"2024-11-29T08:00:37","date_gmt":"2024-11-28T23:00:37","guid":{"rendered":"https:\/\/norimen.net\/wordpress\/?p=53211"},"modified":"2026-06-07T21:56:51","modified_gmt":"2026-06-07T12:56:51","slug":"class-2-no-earth-required","status":"publish","type":"post","link":"https:\/\/norimen.net\/en\/class2-mark-no-earth-needed\/","title":{"rendered":"If You Have a Type 2 Mark, You Don't Need a Ground! Measures to Prevent Electric Shock Accidents!"},"content":{"rendered":"

Hello, everyone.<\/p>\n

This is Enta.<\/p>\n

\"Meeting\"<\/p>\n

The other day, I was contacted by a general contractor, who discussed my next job with me.<\/p>\n

I'm really grateful.<\/p>\n

I truly hope that, little by little, I can be of help to all of you in this way.<\/p>\n

We'll do our best\u2014for the prime contractor's profit (and our own, too)!!<\/p>\n

\n

But that's beside the point.<\/p>\n

Does everyone know this symbol?<\/p>\n

\"Makita<\/p>\n

This is the Makita hammer drill I recently bought.<\/p>\n

This is what's written on the specification label for this hammer drill.<\/p>\n

\"Double<\/p>\n

This is the symbol.<\/p>\n

Did you know?<\/p>\n

\"Makita<\/p>\n

This symbol.<\/p>\n

 <\/p>\n

Actually, I just found out about this myself recently, but,<\/p>\n

This is the symbol for a double-insulation structure.<\/span><\/strong><\/span><\/p>\n

 <\/p>\n

Power tools without this mark have only basic insulation and come with alligator clips or 3-pin plugs, right?<\/p>\n

\"Alligator<\/p>\n

In such cases, you must always install a ground.<\/p>\n

However, electric appliances with a double-insulation design don't need to be grounded!!!!<\/p>\n

 <\/p>\n

Double insulation is,A product that adds \"auxiliary insulation\"\u2014which provides protection in the event of a failure in the standard \"basic insulation\"\u2014to the standard \"basic insulation.\"<\/strong>It seems to be a general term for the structure of [...].<\/p>\n\n\n\n
\n
Double Insulation<\/span><\/div>\n
(Nij\u016bzetsuen)<\/span><\/div>\n
\n

Double insulation refers to a system in which \u201cbasic insulation\u201d\u2014which provides basic protection against electric shock\u2014is supplemented by \u201csupplementary insulation,\u201d which provides protection in the event that the basic insulation fails.<\/p>\n

Even if the primary insulation fails for any reason, the system is designed so that dangerous voltages do not reach the surface thanks to the secondary insulation, thereby ensuring a high level of safety.<\/p>\n

Products with a double-insulation design can be identified by the \"double square\" symbol.
\nIt is frequently used in electrical equipment at construction sites, such as temporary lighting, power drills, and sanders.<\/p>\n

Keep in mind that for electrical equipment with a rated voltage of 150 V or higher\u2014which is required to be \u201cdesigned so that it can be grounded\u201d\u2014there is no need to ground the equipment if it has a double-insulation structure.<\/p>\n

Many electrical devices used in environments prone to contamination from water, dust, and other substances\u2014such as power tools used at construction sites\u2014feature a double-insulation design to enhance safety.<\/p>\n

Conversely, when using electrical equipment that does not have a double-insulation structure, connecting a ground wire is required by law.<\/p>\n<\/div>\n

https:\/\/koujishi.com\/glossary\/<\/div>\n
Electrician.com<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Even if a safety inspection points out that grounding is required, since we use double-insulated power tools, grounding is not necessary!<\/p>\n

I could tell you, but depending on how I put it, it might get complicated, so let's just ask nicely lol<\/p>\n

\"Double<\/p>\n

It's this symbol!<\/p>\n

Please be sure to remember this.<\/p>\n

This type doesn't need a ground connection!!<\/p>\n

 <\/p>\n

That said, if a major company\u2019s internal rules say grounding is absolutely required, then I guess it really is, lol.<\/p>\n

I can just hear someone saying, \u201cEven if that\u2019s true, we still need a ground wire,\u201d lol.<\/p>\n

 <\/p>\n

Well, if you want to be extra safe, grounding is a good idea, but it\u2019s more important to install a ground-fault circuit interrupter.<\/p>\n

 <\/p>\n

\"Ground<\/p>\n

For example, rather than running a single extension cord from a generator to connect to a power tool,<\/p>\n

Place the cord reel with the ground-fault circuit interrupter shown above in between.<\/p>\n

That way, if anything happens, the power will be cut off there.<\/p>\n

 <\/p>\n

The generator side will probably go down too, but we need to set up a system that ensures it goes down even during that process.<\/p>\n

That way, it\u2019s definitely safe, and using power tools with a double-insulation design provides almost complete protection against electric shock, right?<\/p>\n

 <\/p>\n

Please keep that in mind ^^<\/p>\n

We civil engineers aren't very familiar with electrical systems and mechanisms, so I want you to make sure you learn this thoroughly.<\/p>\n

 <\/p>\n

See you later.<\/p>\n

 <\/p>\n

\n

If you're going to buy one, I recommend the 30-meter version.<\/p>\n

As a general rule, the cord reel should be fully extended when in use.<\/p>\n

50 meters is a bit of a slog, so 30 meters is probably more reasonable, lol.<\/p>\n

And the thicker ones are better, you know ^^<\/p>\n

Of course, if it rains, you should stop all work involving power tools immediately!<\/a><\/p><\/blockquote>\n