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In this article, we will focus on "Published Question 2" of the Type 2 Electrician Skills Examination and summarize everything from the concept of wiring diagrams to practical procedures and defect checking, including references.

Publication problem 2 is a set of problems that includes a pilot light (always on), an outlet, and wiring that "turns on two lamps with one switch."

It may seem simple at first glance, but there are many pitfalls, such as forgetting the wiring for a lamp that has been omitted, or handling the pilot lamp incorrectly (according to an explanation on the Gami Denki channel).

This article focuses on information on HOZAN, Gamidenki Channel, and Denkiya Peko.

• What is being asked in Publication Question 2?
• How to think about wiring diagrams (double line diagrams)
• How to recommend practical skills (even where to take a break)
• Common defect patterns

I will organize it in detail.

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Basic information

• Summary of Publication Question 2
• What is the theme of this exam number?

Publication question 2 is a question that combines the following elements.

• Pilot lamp (always on)
• Embedded switch (1 circuit)
• One of the two lamp receptacles (lighting) is omitted (only on the drawing)
• Outlet with grounding terminal (for 100V)
• Power supply is single phase 2 wire 100V (using VVF 1.6 mm²)

The three main themes covered in this question are:

1. Can a pilot lamp's "always on" status be treated as "always on" like an outlet?
   → Connect the wires with the image of always giving the neutral (white) and non-grounded side (black) (from Gamidenki Channel's "Published Problem 2 Explanation").
2. Do you understand the multi-line diagram and wiring rules for the outlet correctly?
   → Do not confuse the "W (white)" and "L (black)" of the grounded electrical outlet.
3. Don't forget to wire the "installation-selected part" to turn on two lamps with one switch.
   → The ability to complement and connect the parts drawn with dotted lines and small lamps in your head in your mind.

In particular, the third part, ``the lamp whose construction was omitted,'' is a point that Gamidenki Channel repeatedly points out, saying that ``quite a lot of people forget this point'' (Gamidenki Channel ``Published Problem 2'').

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#Tools needed for this exam

The basic tool configuration is the same as published problem 1, but the number of pilot lamp and outlet connections increases, so the amount of ``making loops'' and ``tightening terminals'' increases.

• Phillips screwdriver number 2
  → For terminal screws of outlets, switches, pilot lamps, and lamp receptacles.
• flathead screwdriver
  → Removing cables from equipment and fine prying work.
• VVF stripper (VA stripper)
  → Required for sheathing and stripping VVF1.6 mm².
• nipper
  → Cable cutting and ring sleeve “re-cut” processing.
• pliers
  → Twisting the core wire, making rings, and preparing the wire before inserting the ring sleeve.
• Crimping tool (with JIS mark)
  → Crimp the ring sleeve. Crimp 2 to 4 VVF1.6 with "Small".
• Passed multi-tool (HOZAN D-200 series, etc.)
  → Very useful as a gauge for bending mounting frame tabs, pushing ring sleeves, and stripping length.
• Measure/oil pen
  → For measuring and marking cable lengths.

If you don't have the tools yet, you can search Amazon or Yahoo! Shopping with keywords such as "Class 2 Electrician Proficiency Test Tool Set," "VVF Stripper," and "Electrician Knife" to find many complete sets.

On the actual question paper, the ``distance between cores'' of each cable is indicated in dimensions such as 100 mm, 150 mm, and 200 mm. On the other hand, the idea is to cut the cable by adding the length that will fit inside the device or the length required for the joint (Electrical Shop Peko, 2023).

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Materials to be prepared for this exam

The materials typically provided for Publication Question 2 are as shown below (there may be slight differences depending on the year).

• VVF1.6 mm² 2 cores (white/black)
• VVF1.6 mm² 3 cores (white, black, red)
  → Used for wiring and crossover wires to pilot lights and outlets.
• Molded circuit breaker or terminal block (power side)
• Outlet with grounding terminal
• Embedded switch (1 circuit)
• Pilot lamp (indicator light)
• Lamp receptacle (lighting equipment)
• Continuous mounting frame
• Ring sleeve (small)
• Plug-in connector (for 2 to 3 connectors)

On the question paper, the ``center-to-center distance'' of the cable is specified in the form of, for example, 150 mm, 200 mm, or 250 mm. The actual length to be cut is

• Dimensions in the drawing + length to enter the device (20 to 30 mm on one side) x 2
• Additional margin of +50 to 60 mm at the joint part.

We will decide based on this idea. This is the same idea that Denki-ya Peko repeatedly introduces in his explanations of double-line diagrams and measurements (Electric-ya Peko, ``How to determine the candidate problem of double-line diagrams and cable lengths'').

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Main flow

The general flow for completing published question 2 within 40 minutes is as follows.

1. Confirmation of construction conditions (especially pilot lamp "always on" condition)
2. Confirmation of supplied materials
3. Creating a double line diagram
4. Measuring, cutting, and pre-processing of cables
5. Wire connection to equipment/connection of joint part
6. Final check (defect confirmation)

Among these situations, HOZAN's passing multi-tool is particularly useful in the following situations.

• Quickly fix outlets, switches, and pilot lights to the continuous mounting frame.
• Push the ring sleeve firmly to the base
• As a gauge for stripping length, keep it the same length each time.

Gami Denki Channel's construction explanation shows how bending the tabs of the mounting frame using a certified multi-tool allows the work to be done more stably and quickly than with a flat head screwdriver (Gami Denki Channel's "Published Problem 2 Construction Edition").

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How to draw wiring diagrams and things to be careful about

1 Imagine the pilot light as an “outlet”

Publication Question 2 The biggest point is that the pilot light is "always on."

Constant lighting means that the light remains on from the moment the power is turned on, regardless of the switch operation. In other words, you can think of it as ``just like an electrical outlet, L (black) and N (white) are always present'' (Gami Denki Channel ``Published Problem 2 How to Draw a Double-Line Diagram'').

Therefore, in a double line diagram,

• Draw the ungrounded side (black) and grounded side (white) of the power supply so that they go “directly” to both the outlet and the pilot light.

That will be our basic policy.

2 Steps for drawing double-line diagrams (recommended way to draw)

The ``order of how to draw a double-line diagram,'' which is often introduced by Peko the Electrician, is slightly arranged for publication problem 2 as follows.

1. Distribute the ground side (white) to all “loads” first
   • Lamp receptacle (lighting)
   • Lamp whose construction has been omitted (virtual lamp in my head)
   • pilot lamp
   • outlet
2. Take out the non-grounded side (black) from the power supply and distribute it to the outlet and pilot light first.
   → At this point, the outlet and pilot light are always energized.
3. Pass the non-grounded side (black) to the switch
   • An easy-to-understand idea is to draw a "crossover wire" (a short black line) from the L terminal of the pilot lamp to the common terminal of the switch.
4. Draw a "return line" from the switch to the two lamps you want to control.
   • From the switch to the lamp receptacle (the one that actually has the fixture)
   • From the switch to the construction omitted lamp (drawn at the top of the drawing)

The important thing here is that

"The return wire from the switch connects the two lamps in parallel."

It's about having that image.

In single-line diagrams, lamps whose construction has been omitted are often drawn with dotted lines, or lamp symbols are drawn smaller, but in double-line diagrams, it is necessary to draw them exactly like the actual fixtures.

3 Double line diagram of outlet

The outlet is

• Ground side to W terminal (white)
• Non-grounded side to L terminal (black)

It's OK as long as you follow these basic rules.

In published problem 2, the pilot lamp and outlet are often configured to branch from the same joint, and on the double track diagram,

• White wire: Power supply → Joint → Outlet W terminal + Pilot lamp N terminal
• Black wire: Power supply → Joint → Outlet L terminal + Pilot lamp L terminal

It will be easier to understand if you draw them together like this.

4 How to assemble joints

In published problem 2, for joints such as point A and point B,

• A: Plug-in connector
• B: Ring sleeve

There may be specifications such as:

In a double line diagram,

• Count the white lines and black lines that gather at position A
• Count the lines that meet at position B

If you do this while drawing a double-track diagram, it will be easier during construction.

“There are three VVF1.6s here, so there is one small ring sleeve.”

This decision can be made quickly.

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How to proceed with practical skills and take a breather

From here, we will follow the actual procedure step by step and organize where to use the passing multi-tool and where to take a break.

Step 1 Temporarily place the equipment and get an overview (3 minutes)

• Place the outlet, switch, pilot lamp, and lamp receptacle on the practice board roughly in the positions shown in the drawing.
• There is no actual lamp for which construction has been omitted, but we create an image of ``there's another lamp here.''

At this point, we will not fix it yet, but will concentrate on creating an image of where the cable will extend from.

Step 2 Fix the device to the mounting frame (5 minutes)

• Be sure to check the installation conditions to determine whether to attach the outlet and pilot light to the same mounting frame or to the switch side as explained.
• For fixing to the mounting frame, it is efficient to bend the tabs using the tip of a certified multi-tool.

A video on the Gami Denki Channel also shows how pressing the tabs with a multi-tool rather than a flathead screwdriver is more likely to prevent them from slipping and ensure a more secure fixation (Gami Denki Channel's "Published Problem 2 Construction Edition").

This is the first "breathing point".

• Is the equipment about to fall out of the frame?
• Is the frame itself not shaky?

Please check it thoroughly before proceeding to the next step.

Step 3 Measuring, cutting, and stripping the cable (10 minutes)

In published problem 2, there are sections where it would be difficult to redo the cable if the length is incorrect, such as the cable that connects lamp receptacles at a certain distance, or the section that connects the pilot lamp and switch with a short crossover wire.

On the Gamidenki channel,

• With the device in its actual position, measure from center to center with a tape measure, and for example, where it says "250 mm", cut out the cable at that center-to-center distance.

A method is introduced. This will prevent you from misreading the drawing and cutting it too short.

moreover,

• Add 20-30 mm to each end to fit inside the device.
• In total, cut "drawing dimensions + about 40 to 60 mm"

If you allow enough leeway, the core wires will be less likely to become tight during construction.

For sheath stripping and coating stripping, use the gauge engraved on the passed multi-tool or VVF stripper.

• Sheath removal: Approximately 30 mm
• Core wire covering: Approximately 12 mm for outlet, switch, and pilot light

Aligning the parts will give a clean appearance and reduce the risk of defects.

Once you've finished this far, it's time for the second "breathing point."

• Have you disconnected all necessary cables?
• Are there any edges where you forgot to remove the sheath/coating?

Check all at once.

Step 4 Wiring to the equipment (10 minutes)

First, we will connect the equipment that requires constant power supply.

1. outlet
   • White wire to W terminal, black wire to L terminal.
   • If the type has a grounding terminal (earth terminal), connect the green wire if instructed to do so.
2. pilot lamp
   • White wire to N terminal (neutral wire), black wire to L terminal.
     → Image of white and black branching from the same joint as the outlet.
3. Lamp receptacle (actual)
   • White wire (ground side) on the silver screw side.
   • Return wire (line from switch) on the gold screw side.

The basic way to make a ring is to use pliers to make it in a right-handed (clockwise) direction, aligning it with the direction of rotation of the screw. HOZAN's explanation also explains that if the direction of the ring is reversed, the core wire will come undone when the screw is tightened, resulting in a defect (HOZAN "Lamp Receptacle Wiring" explanation).

Step 5 Connection of switch and return wire/crossover wire (7 minutes)

Next is the switch area.

1. Wire from pilot light to switch
   • Connect a short black wire from the L terminal of the pilot lamp to the common terminal of the switch.
     → Power (L) is now supplied to the input side of the switch.
2. Return wire from switch to 2 lamps
   • Branch a return line from the output terminal of the switch to both the actual lamp and the omitted lamp.
   • In a double-line diagram, two lines come out from the switch output and are connected to two lamps in parallel.

On the lamp side where construction is omitted, in reality, only the lines branch within the joint box, so

• Gather the three return wires (from the switch, the actual lamp, and the omitted lamp) at the joint part.

Connect with a ring sleeve or connector.

A common mistake here is the pattern of forgetting the branching of the lamps that have been omitted and connecting only the return wires to the actual lamps.

Step 6 Connecting the joint (ring sleeve/connector) (5 to 7 minutes)

At the joint,

• Plug-in connector specification part
• Ring sleeve designated part

It is very important not to make this mistake.

1. plug-in connector
   • Used to group together 3 white lines, 3 black lines, etc.
   • Adjust the stripped length of the core wire with a gauge, and after inserting it, pull each wire lightly to check if it comes out.
2. ring sleeve
   • Used in areas where 2 to 4 VVF1.6 gather.
   • Twist the core wires together one or two times or more, then use the hole in the multi-tool to push the ring sleeve all the way in.
   • Crimp with the ``small'' crimping tool, and don't forget to ``cut again'' with the nippers at the end.

HOZAN's skill test commentary clearly explains that ``If the core wire is visible from the edge of the ring sleeve for more than 1 cm, it is a defect'' and ``If you forget to cut it, it is also a defect.'' (HOZAN skill test preparation video)

Step 7 Final check (5 minutes)

I just use the last 5 minutes to calm down and check things out.

• Follow the double-track diagram and the actual wiring one by one by pointing.
• Is the wiring set so that the pilot light is always on? (Are you sure the switch is in the wrong position?)
• Are the W and L terminals of the outlet reversed?
• Is the return wire from the switch branched correctly to the two lamps? (Did you forget the installation omitted lamp?)
• Is the crimp mark on the ring sleeve set to "small"?
• Have you forgotten to cut it again?
• Is the connector inserted halfway?
• Is the mounting frame wobbling?

If you can do this up to this point, you will be able to approach the actual Publication Question 2 with a lot of peace of mind.

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Items to check for defects and oversights

Finally, we will summarize the flaws and oversights that are particularly likely to occur in Publication Question 2 as a checklist.

1. The pilot lamp is linked to the switch.
   • Even though it's always on, I wired it to the back of the switch, so it turns on and off.
     → The pilot lamp must be wired to be ``always energized'' in the same way as the outlet.
2. Misconnection of the W/L terminals of the outlet
   • Connect black to the W terminal and white to the L terminal.
     → Be sure to use “W=white” and “L=black” for electrical outlets. There is a stamp on the terminal, so be sure to visually check it before installation.
3. Forgetting to wire the lamp without installation
   • Connect the return wire from the switch only to the actual lamp and you are done.
     → Even if a lamp drawn on a single-line diagram is written as ``construction omitted,'' on a double-line diagram it must be drawn as one unit and branched at a joint.
4. Ring sleeve crimping mistake
   • Even though there are 3 VVF1.6, they are crimped at "Medium".
   • The crimp mark is so crushed that it can't be read.
     → In the Type 2 skill test, 2 to 4 wires of VVF1.6 are in principle "small" and most of the patterns are crimped. It's a good idea to write down in advance where to crimp for each problem.
5. I forgot to cut it again
   • I submitted the ring sleeve without cutting it.
     → It's easy to forget, especially when time is tight, so it's a good idea to decide to spend the last 3 minutes checking the joint again.
6. Insufficient insertion of the plug connector
   • Only a small amount of the copper wire is visible, and if you pull it lightly, it will come out.
     → Get into the habit of pulling each plug gently after inserting them to make sure they don't come out.
7. Wrong direction of ring making
   • The ring of the lamp receptacle or outlet is twisted to the left, and it comes undone when the screw is tightened.
     → All you need to do is practice until you can memorize right-handed (clockwise) winding.

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Finally

Publication question 2 is

• Pilot lamp always on
• outlet polarity
• Installation-free lamp wiring

This is a problem filled with elements typical of a Class 2 electrician.

On the other hand, if you can smoothly handle this problem from double track drawings to construction, you will be able to apply it to other problems that involve pilot lights and electrical outlets.

While watching the videos on HOZAN Yagami Denki Channel and Denkiya Peko, try using your hands several times according to the steps in this article. As you get used to it,

"The pilot light is the same as the outlet. Always turn on L and N."
"The return wires coming out of the switch are wired in parallel, including the installation omitted lamp."

This feeling naturally comes to me.

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Main materials/videos referenced (sources mentioned in the text are in parentheses)

• Gamidenki Channel “Class 2 Electrician Publication Question 2 Explanation (Double-track diagram and construction)”
• HOZAN official "Class 2 electrician skill test preparation video (ring sleeve crimping, lamp receptacle wiring, etc.)"
• Electrician Peko “Class 2 Electrician: How to draw double-line diagrams, how to determine cable lengths, candidate problem explanation series”