When installing a Tesla home charger, one of the most important considerations is determining the proper circuit breaker size. The size of the circuit breaker must be large enough to handle the electric load of the Tesla charger, while not exceeding the capacity of the electrical system. Choosing the right breaker size is crucial for safety and optimal charging performance.
Quick Answers
Here are quick answers to some common questions about Tesla charger circuit breaker sizes:
- For a Tesla Wall Connector (the standard Tesla home charger), a 60 amp or 80 amp circuit breaker is recommended.
- Higher amperage breakers allow faster charging, but require sufficiently sized electrical wiring.
- The Tesla Mobile Connector that comes with Tesla vehicles can work on lower amperage circuits, like 20-30 amps.
- Always follow local electrical codes and have an electrician size and install the circuit breaker.
- The breaker size must match the capacity of the electrical system, including the wiring, utility service, etc.
Tesla Wall Connector Breaker Requirements
The Tesla Wall Connector is the standard Level 2 home charging unit included with a Tesla purchase. It provides significantly faster charging than the regular Mobile Connector. According to Tesla, the Wall Connector requires a 60 amp or 80 amp circuit breaker. Either size will work, but the larger 80 amp breaker will enable faster charging.
Here are the specifications for the Tesla Wall Connector breaker requirements:
- 60 amp circuit breaker: Allows up to 44 amps (9.6 kW) of charging
- 80 amp circuit breaker: Allows up to 48 amps (11.5 kW) of charging
- Wall Connector max charging rate: 11.5 kW (48 amps)
With an 80 amp breaker, the Wall Connector can charge at its maximum rated power of 11.5 kW. This provides about 45 miles of range per hour of charging for most Tesla models. The 60 amp breaker slightly limits the charging rate to 9.6 kW, but still provides over 30 miles of range per hour.
Considerations for Choosing 60 Amp vs 80 Amp Breaker
When installing a new Wall Connector circuit, an 80 amp breaker is recommended if the electrical system can handle it. However, there are some reasons you may need to use a 60 amp breaker instead:
- The existing wiring is only rated for 60 amps
- The utility service/meter limits the total home load to less than an 80 amp circuit
- Cost savings from using smaller wiring gauge for a 60 amp circuit
- You don’t need max charging speed and a 60 amp circuit will suffice
Consult your electrician to determine if your home’s electrical system can accommodate an 80 amp circuit or if a 60 amp circuit is more appropriate.
Mobile Connector Circuit Breaker Needs
The Mobile Connector that comes standard with all new Tesla vehicles is a lightweight portable charger. It can plug into a regular wall outlet or be hardwired to a dedicated circuit. The Mobile Connector has adjustable charge rates from 8-12 amps on a 15 amp breaker up to 40 amps on a 50 amp breaker. Here are the common circuit breaker sizes used with the Mobile Connector:
| Circuit Breaker Size | Maximum Charging Rate |
|---|---|
| 15 amps | 12 amps (2.8 kW) |
| 20 amps | 16 amps (3.8 kW) |
| 30 amps | 24 amps (5.6 kW) |
| 40 amps | 32 amps (7.6 kW) |
| 50 amps | 40 amps (9.6 kW) |
With lower amperage circuits, the charging rate and speed will be reduced. But the benefit is that smaller, cheaper circuit breakers can be used.
Recommended: 30-50 Amp Breaker for Mobile Connector
Tesla recommends using a 30 amp or larger breaker for the Mobile Connector when hardwired. This provides a good balance of charging speed versus installation cost. A 30 amp breaker allows overnight charging on most circuits, while a 40-50 amp breaker provides even faster charging for flexibility.
Electrical System Capacity is Key
When determining the circuit breaker size, the amperage rating of the breaker must align with the capacity of the home’s electrical system. The wiring size, utility service, main panel rating, and other factors must be verified. Some key points:
- The wiring must be thick enough gauge to safely handle the amperage
- The main circuit breaker/utility service must have sufficient amps remaining
- Applicable electrical codes must be followed
- An electrician should always size and install the circuit breaker
Installing too large of a breaker can overload the wiring which can cause fires or other major safety issues. Hiring a qualified electrician is highly recommended for any Wall Connector or hardwired Mobile Connector installation.
Wiring and Conduit Requirements
Here are the recommended wiring sizes and conduit types for various amperage Tesla charger circuits:
| Circuit Breaker | Minimum Wire Size | Conduit Recommendation |
|---|---|---|
| 60 amps | 6 AWG copper | 1″ conduit |
| 80 amps | 6 AWG copper | 1″ conduit |
| 30 amps | 10 AWG copper | 3/4″ conduit |
| 40 amps | 8 AWG copper | 3/4″ conduit |
| 50 amps | 6 AWG copper | 3/4″ conduit |
These recommendations are based on the National Electrical Code (NEC) standards in the US. The conduit provides physical protection for the wires. Always check local building codes for exact requirements.
Tesla Charger Voltage and Phase Requirements
In addition to selecting the proper amperage circuit breaker, the line voltage and phase requirements must be met:
- The Wall Connector requires 208-250V single phase input
- The Mobile Connector requires 110-240V single phase input
Most standard residential circuits are 120/240V single phase which meets these needs. But for some commercial or industrial electrical services, verify that the supply voltage and phases match the charger requirements before installing.
GFCI and AFCI Circuit Breaker Options
Ground fault circuit interrupter (GFCI) and arc fault circuit interrupter (AFCI) breakers provide added safety and protection. Here are some guidelines if you choose to use them for a Tesla charger circuit:
- A GFCI breaker is recommended for any outdoor charger installation
- Indoor installations generally don’t require a GFCI breaker
- Use a standard or CAFI circuit breaker for indoor, dry locations
- An AFCI breaker provides protection against arc faults
- Combination AFCI/GFCI breakers are available
- Follow local electrical codes for GFCI/AFCI requirements
The Tesla Wall Connector and Mobile Connector have built-in GFCI monitoring that may allow using a standard circuit breaker. Check with your electrician on the best options for your individual installation and situation.
Electrical Panel and Breaker Considerations
The home’s main electrical panel must also be properly sized to accommodate the added load from the Tesla charger.
Some best practices include:
- Confirm the main breaker rating; 100 amps is common for older homes
- Calculate the total current draw with the added charger circuit
- See if the main panel needs to be upgraded to a larger amperage
- Leave room for additional future circuits and expansion
- Use a dedicated breaker at the panel for the charger wiring
Upgrading an older electrical panel may be needed to allow installing a higher amperage charger circuit. This is especially true when adding an 80 amp circuit for the Wall Connector in an older home.
The electrical panel breaker type (single pole, double pole, etc) must also match the Tesla charger wiring configuration.
Consider a Load Sharing Setup
For situations where the home electrical service is limited, a load sharing setup can allow powering multiple Tesla Wall Connectors from a single circuit:
- Uses Tesla’s smart load sharing feature
- Allows 2-4 Wall Connectors on one circuit
- Reduces installation cost and panel spaces used
- Manages power across chargers as needed
This distributes the available power across vehicles automatically as they charge. For example, two Wall Connectors could share a 100 amp circuit. The total charging rate is reduced, but both vehicles can still charge simultaneously.
Consult an Experienced Electrician
Determining the proper circuit breaker size and installation requirements for a Tesla Wall Connector or Mobile Connector involves many technical considerations. Always consult with a qualified, licensed electrician who has experience with EV charger installations.
An experienced electrician will:
- Correctly size the circuit breaker based on your electrical system
- Determine if your panel needs to be upgraded
- Install appropriate conduit and wiring for the charger amperage
- Pull permits and schedule inspections as required
- Help you take advantage of any local, state, or federal EV charger incentives or rebates
Investing in a professional electrical installation will help ensure your Tesla charger is set up correctly and safely.
DIY Installation Not Recommended
Tesla does provide installation manuals and documentation for handy homeowners. But they strongly recommend having a certified electrician install any Wall Connector or hardwired Mobile Connector:
- Prevents potential safety hazards from improper installation
- Helps ensure the system meets all national and local electrical codes
- May be required anyway to pass final inspection in many regions
- Provides peace of mind knowing the system was installed correctly
So while a DIY EV charger installation may seem possible for some handy homeowners, professional installation is almost always worth the added cost for such a critical system.
Conclusion
When installing a Tesla home charger, selecting the proper circuit breaker size is an important decision. For a Wall Connector, a 60 amp or 80 amp breaker is recommended depending on your home’s electrical capacity. Lower amperage circuits (15-50 amps) can work for the Mobile Connector in certain situations. Always consult a qualified electrician to determine the optimal circuit breaker rating based on your existing electrical panel, wiring, and overall system capacity. This helps ensure a safe, effective Tesla charging setup.