[Class 2 Electrician Skills Examination] Published Problem 5 Strategy Guide [200V Outlet with Grounding Terminal]

12/09/2025

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(Time switch + terminal block + 100V outlet/single-phase 2-system circuit)

Publication question 5 is one of the ``high points'' that you should practice thoroughly among the candidate questions.
The level of difficulty is said to be 4 out of 5, as there are two single-phase power circuits, and a 100V outlet with a terminal block, which is rarely seen, and a time switch come as a set. (Electricist Peco)

This article is based on the explanations provided by HOZAN, Gamidenki Channel, and Denkiya Peko.
From ``How to think about double-line diagrams'' to ``How to connect terminal blocks and time switches'' to ``Rules for 4-IV joints''.
We will organize the exercises at a level where even beginners can complete the practice just by using this page.

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Table of Contents

Basic information

Class 2 electrician skill test published question 5
This work involves two systems of single-phase, two-wire power supply circuits, and is a combination of time switches, terminal blocks, 100V outlets, and lighting equipment. (Electricist Peco)
What is the theme of this exam number?
- Correctly organize and wire the "two systems" of single-phase two-wire power supply using terminal blocks.
- Understand the meaning of the time switch terminals (S1, S2, L1, etc.) and insert the non-installation side and installation side into the correct terminals.
- Observe the polarity of the 100V outlet with a terminal block (white wire on the W terminal, black wire on the other) (Electricist Peko)
- At the joint part, please adhere to the installation conditions such as ``Plug-in connector only where 4 IVs are connected, and ring sleeve everywhere else'' (Electricist Peco)

Once you understand this, you will be able to apply it to published problem 4 and other terminal block problems at once.

Tools needed for this exam

In addition to basic tools, it is important to ``reliably align the dimensions and peel off'' around the terminal block and time switch.

Electrical knife (for stripping the exterior. Cuts 5cm, 10cm, etc. of VVF exterior) (Hozan)
va stripper
- It is convenient to use one with a gauge at the position where you want to strip 10mm of the 1.6mm² core wire. (Hozan)
- HOZAN's VA strippers and passing multi-tools are popular among test takers as they are easy to match with a 10mm core wire and a 20mm exterior in one go (candidates can be found by searching for "HOZAN VA stripper P-958" or "HOZAN passing multi-tool" on Amazon or Yahoo Shopping).
Crimping pliers (for ring sleeves. Crimp with the correct markings on sleeves of specified size) (Hozan)
nipper pliers
Driver (+/-)
Voltage detector/tester (We do not check the power during the actual performance, but it is safe to have it for self-checking during practice)

The good thing about “passing multi-tools” is that
・Exterior stripping length guide
・Guide for core wire 10mm strip
・VVF exterior notch enters stably
In that sense, you can use it for multiple roles, so you can use it consistently from practice to actual performance with the same feeling.

Materials to be prepared for this exam

The actual length and number may vary slightly from year to year, but the composition image is almost the same.

VVF cable
- 1.6mm² 2-core (black/white): power supply to terminal block, terminal block to outlet, terminal block to joint box, etc.
- 1.6mm² 3-core (black, white, red): Used for multi-core wiring around time switches and terminal blocks
- When practicing, it is easier to handle if you align the outer 5cm + core wire 10mm on the terminal block side, and the box side with the outer 10cm + core wire 10mm as standard. (Hozan)
IV wire (single core vinyl insulated wire)
- 1.6mm² (black, white, red as required): Connection between terminal block and time switch, terminal block and lighting equipment, etc.
- There is a place around the time switch where 4 IVs gather in one place, and the key point is that this is the only place where a plug-in connector is specified. (Electricist Peco)
utensils
- Terminal block (type used as a substitute for molded circuit breaker + earth leakage breaker + 100V outlet/time switch) (Hozan)
- time switch body
- hook ceiling
- lamp receptacle
- Embedded switch (single cut)
- Built-in outlet (with W indication)
- Continuous mounting frame (must be used if provided. If not used, it will be considered unfinished) (Hozan)
joint parts
- Ring sleeve (small)
- Plug-in connector (for 2 or 3 wires)

The installation conditions specify that ``if you are using four IVs, use a plug-in connector, otherwise use a ring sleeve.''
When practicing, be aware of where the joints will be for 4 IVs. (Electricist Peco)

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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Main flow

Publication question 5 has a complex structure, so it is recommended that you first keep in mind the "overall setup" before moving on.

Confirmation of question paper and construction conditions
- Be sure to read the test center's construction conditions, such as ``Two single-phase two-wire power supplies'' and ``4 IVs are plug-in connectors, and the others are ring sleeves.'' (Electricist Peco)
Confirmation of supplied items
- Check the quantity of cables, equipment, ring sleeves, and plug-in connectors, and report any shortages to the examiner.
Creating a double line diagram (goal: within 3 minutes)
- Quickly draw double-line diagrams using your own patterns, such as Gamidenki's ``4 Steps to Victory.'' (Gamidenki channel)
Dimensioning, cable cutting, exterior stripping
- Determine the length of each section and cut the cable all at once.
- Peel off the joint box side with an exterior of about 10 cm and core wire of about 10 mm, and the appliance side with a standard multi-tool or VA stripper, using a standard multi-tool or VA stripper.
Equipment attachment/terminal block/time switch wiring
- Attach the switch/outlet to the continuous frame first and check the polarity. (Electricist Peco)
- Arrange the N, L, and TS terminals on the terminal block side, and insert the IV wire and VVF into the designated positions.
- Correctly connect the power supply L (S1), power supply N (S2), and load side wires to the time switch.
Wiring inside the joint box
- While counting the number of VVF/IV, connect them with ring sleeves/plug-in connectors as specified. (Electricist Peco)
Final confirmation
- We check each appliance for polarity, connection errors, protruding coatings, and how well the exterior covers.

(How to use the passing multi-tool)

VVF exterior 5cm and 10cm available
Accurately strip 10mm of core wire
Machining 5 cm of exterior wire and 10 mm of core wire on the terminal block side "many times to the same length" at once
It can perform these simple tasks quickly and uniformly, which is a great advantage for skill exams that only take 40 minutes.

How to draw wiring diagrams and things to be careful about

There are three points that can easily cause you to stumble on the multi-line diagram in Publication Question 5:

There are two single-phase power supply circuits.
The terminal block replaces the “hardwire circuit breaker + earth leakage circuit breaker”
Route to the hook ceiling via the time switch

Here, we will organize it using the Gamidenki style ``4 steps''.

Step 1: Copy the equipment exactly as it is

From the single-line diagram on the question paper, copy the power supply, terminal block, time switch, joint box, lighting equipment, and outlet directly onto the whiteboard or in the empty spaces on the question paper.
The terminal block has terminal numbers N, L, and TS (L1, etc.) indicated, so writing them in small letters below the diagram will prevent connection mistakes later.

Step 2: Pass power N (white) through all loads

As a general rule, one wire on the installation side (N side white wire) always reaches "all load appliances (lights, outlets)".
In published problem 5, there is a section where the N side goes through "terminal block → time switch → hook ceiling", so
"Going directly from the joint box to the ceiling" is no good. Don't forget the wiring that goes through the time switch. Hozan

Step 3: Connect power L (black) to switch/outlet/time switch

The non-installation side (L side black wire) goes into the switch, outlet, and time switch.
The installation conditions state that ``all wires on the non-installation side from the power source to the switch, outlet, and time switch should be black,'' so do not mix other colors here.
The time switch terminals are determined based on the internal circuit.
- Power supply L → S1
- Power supply N → S2
- Load side (to hook ceiling) → L1, etc.
  In this way, power is supplied to the motor between S1 and S2, and the L1 side is turned on and off by a timer operation.

Step 4: Match each switch to load equipment

A switch → A lamp
B switch → B lamp
Connect the ``switch proxy line'' and ``load side'' according to the symbols on the problem diagram. (Gamidenki channel)
It is also important to check which appliance is controlled by the time switch (usually a hook ceiling) and connect that appliance directly from the time switch without going through the switch.

If you have drawn the double-track diagram correctly, you will naturally be able to see where the four IVs meet in the joint box, terminal block, and time switch.
If you mark the rule on the double-track diagram to use the plug-in connector only in that location, you will be less likely to get confused during the actual production. (Electricist Peco)

How to proceed with practical skills and take a breather

From here, let's imagine how to actually move your hands with a time allocation.
It will be more stable if you roughly divide the 40 minute test time as follows.

Material confirmation/construction condition check: 5 minutes
Double track diagram: 3-5 minutes
Dimensioning/cable processing: 10-12 minutes
Equipment attachment/terminal block/time switch: 10 to 12 minutes
Joint connection: 5 to 7 minutes
Final check: 3-5 minutes

Cable dimensions and strip length

In the explanation by electrician Peko,
"Where it says the specified size is 150 mm, if you cut it to 250 to 300 mm, you won't run out."
“It will not be a defect unless it is less than 50% of the specified coating length.”
A practical guideline is presented. (Electricist Peco)

However, it is safer to leave a margin in the exam, so it is easier to handle if the following is the standard.

Terminal block side (VVF): Exterior 5cm, core wire 10mm
Outlet box side: Exterior 10cm, core wire 10mm
Hook ceiling/lamp receptacle: Core wire 10mm (make a wire and insert it into the terminal)
Time switch/terminal block IV wire: Core wire 10mm

If you use a passing multi-tool or a stripper with a gauge, you can almost automatically align these dimensions, reducing the number of measurements and saving time.

Construction of terminal block

In the HOZAN video, the cable processing on the terminal block side is done quite carefully.

Prepare 3 VVF 2 cores (I, Ro, Ha, etc.) with a specified length (e.g. 350mm) to be inserted into the terminal block.
Strip the terminal block side with 5cm exterior + 10mm core wire.
Outlet box side: Exterior 10cm + core wire 10mm
If the terminal block screws are closed, loosen them slightly before inserting the cable.
Insert it according to the specified number (black line at 1, white line at 2, etc.) and tighten the screw firmly.

For terminal blocks, it is important that the outer sheath is at least a few mm deep inside the pedestal and that the core wire sheathing is not too exposed when viewed from below. Be careful not to cut too much to the point where the exterior is not visible, as this may result in defects. Hozan

time switch wiring

Wiring the time switch while imagining its internal structure will make it easier to get lost.

S1: Non-installation side of power supply (L: black)
S2: Power supply installation side (N: white)
L1: Load side (line towards hook ceiling)

Connect these three wires to the terminal block or joint box using IV wires.
The section that goes to the hook ceiling via the time switch is
After checking the flow on the N side from "Joint Box → Time Switch → Hook Ceiling" on the double line diagram, let's move on to the actual wiring. Hozan

100V outlet polarity

On the outlet side,

White line on the W mark (White) side (N side)
Black line on the other side (L side)
so that it enters. (Electricist Peco)

After the battle, be sure to visually check that the core wire protrudes within 5 mm and that there is a white line on the W side when the screws are tightened. (Electricist Peco)

breathing point

The most important part is where the terminal block and time switch area are finished.
If you can finish in about 25 minutes up to this point, you'll be on time.
Before you start wiring the joint box, stop and mark the areas where there will be 4 IVs and the ring sleeve before proceeding. This will calm your heart rate and reduce mistakes. (Electricist Peco)

Items to check for defects and oversights

Finally, I will summarize the flaws that are particularly likely to occur in Publication Question 5.

Wrong terminal number on terminal block
- Mistaking N side and L side
- Accidentally inserting a load wire directly into the time switch terminal (TS terminal)
  → Check the diagram below of the terminal block (explanatory diagram on the question paper) and check which terminal corresponds to which device by comparing it with the double-track diagram.
Reverse connection of S1 and S2 of time switch
- Add a white line to S1 and a black line to S2
  → The installation conditions often include "white line on time switch S2", so be sure to get into the habit of reading the text. Hozan
Connect N directly from the joint box to the ceiling without going through a time switch.
- If you look closely at the single-line diagram, you'll see that it says "via a time switch," so make sure you don't make a mistake in the route when you look at the double-track diagram.
Wrong connection tool for 4 IV joints
- Even though there are 4 IVs, they are crimped with the ring sleeve.
- Conversely, plug-in connectors are used to connect 2 to 3 wires.
  → Confirm the installation conditions out loud: ``If you are using 4 IVs, use a plug-in connector, otherwise use a ring sleeve'' before connecting. (Electricist Peco)
Incorrect outlet polarity
- I put a black line on the W side and a white line on the other side.
  → Remember “W=White” and be sure to confirm it again during the final check. (Electricist Peco)
Exposed core wire length/insufficient sheathing
- The core wire protrudes by 5 mm or more from the terminal block or outlet.
- The exterior is not inside the pedestal, and the core wire coating is fully visible when viewed from below.
  → The HOZAN video also emphasizes that ``the exterior is inside the pedestal, and the exposed core wire is within 5mm.''
Forgetting to attach the continuous mounting frame
- If you do not use the provided item, it will be treated as unfinished, so check the surroundings of switches and outlets. Hozan

Based on this article, try practicing by dividing it into ``just the double-track diagram'' and ``just the terminal block and time switch''.
Once you get used to it, time yourself for 40 minutes and use HOZAN's passing multi-tool to solidify your own steps.

Next time, I will explain Publication Question 6 while organizing the "theme and pitfalls" in the same way.