The Story of 'Numbers' Beyond 'Passing': Protecting Someone's Smile [Second-Class Electrician Written Exam Preparation]

Are you sighing right now in front of the inanimate numbers lined up in your textbook? '1.5m', '2m', '6 times'... If you try to just memorize them by rote, it might be a painful task.

However, stop and think for a moment. That line, that number you are learning right now, is not just a tool to pass an exam. It is a bible for protecting 'someone's daily life and safety' beyond the construction work you will handle in the future!

Give your all to this very moment. Let's pour that passion into these wiring construction rules!

1. The Iron Rule: Rules Named 'Kindness'

First, the '6 times' rule, which is the foundation of everything. Why must we make it 'gentle' when bending conduit?

If you bend it sharply, the wires inside will be damaged and cannot perform as intended. 'Don't bend the pipe un-reason-ably (6)!'. Don't you think this number '6' is, in itself, 'consideration' for the wires and for the people who use them!

And connecting wires inside a conduit is absolutely, absolutely forbidden! When there is trouble, cutting corners in hidden places makes someone unhappy. If you must connect them, always do it inside a 'box' that acts like a spacious parking area. Sincere work is the proof of a professional.

Not putting outdoor 'OW wire' into conduit is also a judgment of using the right tool for the right place. 'Don't put in the OW (over/finished) wire'.. Make this decision your own right here and now!

2. Synthetic Resin Conduit: A Harmony of Trust and Self-Reliance

When handling plastic conduit (such as VE conduit), what we face is the drama of 'fixing' and 'connecting'.

• Distance between support points is 1.5m or less: 'Plastic likes strawberries (1.5)'.. What a lovely, and reliable, sense of distance.

• The philosophy of insertion depth: This is important! If you trust your partner, the adhesive, then a shallow '0.8 times or more'. If you don't use adhesive and challenge it with your own strength alone, then a deep '1.2 times or more'. 'Trust or self-reliance'.. This dialogue is what determines the quality of the site!

3. Metal Conduit and Cables: Professional Pride Residing in the Details

• Metal conduit: If embedding in concrete, use a thickness of 1.2mm or more to withstand the pressure. Cover the cut ends with insulating bushings to protect the wires from damage. Never let them touch the metal wall (metal lath). This obsession becomes the breakwater that prevents fires.

• Cable work: The basic distance between support points is 2m or less. Please gently guide the 'wiggly (2)' cables. However! If it is in a 'place where there is no risk of people touching it' and you are installing it 'vertically', you can use gravity to your advantage and extend the interval to 6m or less. The eye to discern the conditions—that is the professional's judgment!

4. Lighting Ducts: A Fusion of Safety and Aesthetics

Even ducts that illuminate stylish spaces have strict safety standards.

• The opening must face downward and the terminal end must be protected with a cover (end cap).

• Do not penetrate structural members (walls or ceilings). Beauty is built upon safety.

• Grounding to protect lives: In principle, Class D grounding work must be performed. However, it can be omitted if the 'voltage to ground is 150V or less' and the 'duct length is 4m or less.' This is a special exception allowed only when safety is guaranteed by being 'short and low voltage'!

5. Today's Summary: 'Organizing the Numbers'

I have summarized the points I want you to remember today!

Everyone, are you ready! 'Grounding can be omitted if it is 150V or less and 4m or less.' Do not let these numbers end up as mere rote memorization. Why can it be omitted? Because safety is already ensured.
Knowing the rules means gaining freedom. And it means taking responsibility.

If you find an incorrect option in an exam question, shout in your heart, 'No! That's not safe!'
'If not now, when!' With that passion, the two characters for 'pass' are already within your reach.

I am cheering for your challenge from the bottom of my heart!

If you get stuck in your studies, please call on me for a break!