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For those who are renovating their homes and are wondering what to do with their distribution board (breaker box).We will thoroughly explain how to choose a 60A distribution board, which is useful for those who think, "We might introduce solar power generation, storage batteries, and EV chargers in the future, but we're still a while..." or those who want to support renewable energy right now!"

In this article, we will explain in an easy-to-understand manner what kind of board will suit the standard 60A main distribution board, from the perspectives of "initial costs," "future response capabilities," and "difficulty of construction."

So, here you go.

What is a distribution board?How long does it last?

The distribution board is the "heart of electricity" that safely distributes electricity throughout the house.Not only does it divide electricity into air conditioners, induction heaters, lighting, etc., but it also plays an important role in protecting your home appliances and homes from leakage and overcurrent.

The lifespan of a household distribution board is generally considered to be 13 to 15 years (survey of the Japan Electric Manufacturers Association).After 15 years, internal breakers and insulating components are likely to deteriorate, increasing the risk of malfunction and heat generation, so you should consider updating them.

This is a great opportunity to replace the product, especially when renovating or in full skeleton state.There is no need to open the wall, so construction costs can be significantly reduced compared to replacing it later.

Is 60A sufficient?Contract Ampere's concept

The question "Is the 60A okay? What should I do if I run out of stock?" is a frequently asked question for those who are choosing a distribution board for the first time.

To put it simply,For a typical detached house (family of 3-5), 60A is sufficient.Rather,Considering the current contract structure of electric power companies and the status of all-electricity support, there are many regions where 60A is the maximum "maximum ampere", and the most selected standard is the 60A..

What is amperage?

A contract ampere (A) is a number that indicates the upper limit of current that can be used simultaneously across the entire house.Since electricity is calculated as "voltage (V) x current (A) = power (W), 60A means

• Use only 100V equipment: 100V x 60A = Can be used simultaneously up to 6000W (6kW)
• Including the use of 200V devices (IH, Ecocute, and EV), the actual supply is efficiently carried out by circuit division.

How long can it be used?Typical home appliance guide

In other words, if simultaneous use occurs, such as "Cooking on an induction, turning the washer and dryer, and microwave oven..."Possibility of temporary exceeding 50A to 60AIt's not zero either.

However, current distribution boards and contract structures provide "overcurrent countermeasures for each branch circuit," soJust because it exceeds 60A for a moment doesn't mean that the electricity in the house will go down, only overloaded circuits will be cut off by the breaker..

Are you worried about the 60A in the all-electric and EV era?

Certainly, if you install EV charging or large storage batteries in the future, there may be situations where the battery exceeds 60A.

However, major Japanese electric power companies (such as Tokyo Electric Power Company and Kansai Electric Power Company)The maximum contract ampere is 60A in principleto.If this exceeds this,You need to switch to "Main switch contract (no breaker contract)" or "Low voltage power contract (for commercial use)"Therefore, it is a special case for residential use.

Conclusion: If you're unsure, 60A is OK

• 60A is enough for a normal household
• If you live in a lifestyle where it is used more frequently at the same time, you can adjust it by using the split circuit distribution and time difference.
• Even if you install renewable energy devices afterwards, you can handle them by installing a separate dedicated circuit.
• If you are unsure, it is easier to change your contract in the future by keeping the 60A contract with a "main breaker 75A compatible board"

In other words, "If you're unsure, 60A" is fine.Depending on the ingenuity and design on the distribution board, you can live comfortably even with a 60A contract..

What will happen if we look at future changes in law and institutions?

Starting in 2025, energy-saving standards will become mandatory even for homes with a capacity of less than 300m².Furthermore, towards 2030, the government has set a policy of "sunlight is standardized in 60% of newly built homes."

In other words, even if there are no plans to introduce renewable energy now, there is a high possibility that it will become a "required" in a few years.

To meet the ZEH (Net Zero Energy House) standards, the following functions are required:

• Power measurement for each circuit (=HEMS linkage)
• Separate three power supply sections: solar, storage battery, and EV
• Lightning Surge Protection (SPD)
• Seismic Sensor Blocking Device (Automatically blocks electricity in the event of an earthquake)

If you try to "add" these functions later, the entire distribution board will be replaced, which doubles the cost and effort.

What is HEMS?What role does it have?

HEMS stands for "Home Energy Management System" and is a system that "visualizes" electricity usage in the home and reduces electricity waste.

To put it more simply, HEMS is like a "household electricity account book + controller."You can grasp all the power usage within your home in real time, including lighting, air conditioners, induction and outlets, and check the data as graphs and numbers on your smartphone or tablet.

Why do you need HEMS?

With the current ZEH subsidy system and the future implementation of VPPs (virtual power plants) and DRs (demand response), "being able to manage the energy of your home" is a must-have condition.Having HEMS offers the following benefits:

• I can see that I use too much electricity in my home, and I feel more aware of energy saving
• It can increase the self-consumption rate of solar power generation (more economical to use it yourself than selling electricity)
• Avoid high electricity bills and use them wisely
• Cooperation with storage batteries and EVs (electric vehicles) makes it easier to secure electricity in the event of a power outage

What kinds are there?

There are two main types of HEMS:

1. A built-in/connected to a distribution board from the beginning (e.g. Smart Cosmo + AiSEG3)
   → Compatible with the common communication standard called ECHONET Lite, which is eligible for subsidies.It is the mainstream of ZEH-compatible homes.
2. An external installation type afterwards (e.g. Nature Remo E2)
   → It can be easily installed and visualized without updating the distribution board.There are also simple but subsidies available.

How to install HEMS?

To install HEMS, you will need to either "install the measurement sensor on the distribution board" or "install an already built-in HEMS compatible distribution board."Additionally, you can choose the HEMS main unit (controller) based on the home use situation, such as AiSEG or Remo E2.

In an age of renewable energy and energy saving, HEMS is not just an option, but an important facility so important that it can be called "the brains of the house."When choosing a distribution board, check whether the configuration is compatible with HEMS, and you can reduce future regrets.

How to choose a 60A distribution board: Comparison of four types

Recommended composition patterns with an eye toward the future

Pattern 1: For those who just want to get it cheap

• ECHONET Lite compatible external HEMS such as the "Standard Edition" + "Nature Remo E2" enables circuit-specific measurements
• If you reserve 2-4 free modules (spaces), you can attach a PV breaker after the
• When installing PVs in the future, you can simply insert a 40A solar breaker to handle this.

Pattern 2: Ensuring minimal scalability while aiming for subsidies

• Introducing a ready-made version such as Panasonic's "Smart Cosmo BHR86142J"
• Initial costs are high, but sensor wiring and communication harnesses have been installed at the factory.
• In the future, we can meet the requirements for ZEH subsidies by adding HEMS controllers such as AiSEG.

Pattern 3: If future introduction of renewable energy is almost certain

• Choose a fully compatible ZEH type with built-in PV/storage battery/EV charger breakers, SPDs, and seismic blocking devices, including Panasonic's "BHMF86222J".
• By combining AiSEG3 and other devices, it can also be used for VPP and DR (power supply and demand response).
• It is easy to apply for subsidies (ZEH up to 600,000 yen, GX-oriented type up to 1.6 million yen)

Replacing the panel is surprisingly difficult.It's definitely a good deal to install inside the skeleton

It's often thought, "If the amperage does not change, it can be easily replaced later?", but in reality it's not that easy.

When replacing the distribution board in an existing home:

• Wall openings and repairs are required (cross and plasterboard)
• Temporary power outage application to the electric power company
• Extend and re-crimp power and ground wires
• Construction time is 4 to 6 hours, and costs around 70,000 to 100,000 yen

On the other hand, when installing in a skeleton:

• Wiring can be completed before finishing the wall
• Construction time: 2-3 hours, cost: 50,000 to 70,000 yen

In other words, by keeping it in "now", you can significantly reduce additional costs and hassle in the future.

Construction points and points to note

• The work must be carried out by a qualified person above the second class electrician (legal obligation)
• When replacing the distribution board, insulation resistance tests and ground resistance measurements must also be performed (fire prevention)
• If you plan to install solar and storage batteries afterwards, it will be smoother if you lay two PF tubes (diameter 22mm) in advance.
• If you are considering charging EVs in the future, it is best to have at least three empty modules so that you can install a 200V 2P2E dedicated breaker.

Conclusion: What is the "strongest distribution board" for you?

• I just want it cheap, but I also want a minimum of future potential → Standard edition + external HEMS
• Renewable energy is gently supported while taking advantage of subsidies → Ready model (semi-smart)
• Renewable energy is almost confirmed, and I want to complete the board in one go → Initial introduction of ZEH compatible models

With any option, future freedom can change dramatically depending on how you think, "preserve an empty circuit" or "pass piping first."

If you're wondering "How much renovation or remodeling can I actually do on my own home?" or "Where should I even start?", please visit this page. If you're looking to learn more about specific renovation processes or construction details, don't miss this page as well!

References, products, and websites

• Panasonic Smart Cosmo Series Official Page
• Kawamura Electric Eco-Eye Cloud HEMS
• Nature Remo E2 Product Information
• Ministry of Economy, Trade and Industry and Ministry of Land, Infrastructure, Transport and Tourism ZEH related publication materials
• Japan Electrical Manufacturers Association "Report on the lifespan of distribution boards"
• Electrician Act and PSE Act (Brief explanation)

We hope this article will be of use to create homes with a look into the future and DIY renovations.