By Alvin Wong, CEO of Innovative Green Power Sdn. Bhd.
When it comes to EV charging protection systems, the choice of circuit breakers is not just a matter of cost — it’s a matter of safety, reliability, and long-term performance. Two names often raised in discussions are Terasaki and TEMLite. But are they the same? And more importantly, should they be used together in the same circuit?
The short answer is: No, they are not the same, and they should not be mixed in a single EV charging protection system.
Why Circuit Breaker Quality Matters More in EV Charging
Unlike most household appliances, EV chargers demand high continuous current over long charging sessions. A 7kW to 22kW wallbox, for example, may run for hours at near-maximum load.
This puts sustained stress on protective components, including:
- MCBs (Miniature Circuit Breakers) for overload and short-circuit protection
- RCCBs (Residual Current Circuit Breakers) for leakage and life safety
- MCBs and RCCBs in combination, which must work seamlessly under demanding conditions
Inconsistent or low-quality protection devices can lead to:
- Overheating of contacts due to poor material quality
- Nuisance tripping under normal charging loads
- Reduced lifespan of the breakers from continuous stress
- Failure to trip in a real fault scenario, potentially resulting in fire or electrocution
For EV charging, the margin for error is slim. That’s why consistent, industrial-grade components are non-negotiable.
Terasaki: A Benchmark in Quality
Terasaki is a Japanese manufacturer with a long track record in electrical protection systems. Known globally for:
- High build quality and durability, suitable for critical infrastructure
- Certified IEC compliance and consistent factory testing
- High breaking capacities (often 10kA or more), ideal for heavy EV loads
- Use in marine, industrial, and EV charging installations where uptime and safety are crucial
In short, Terasaki breakers are designed for environments where failure is not an option.
TEMLite: A More Budget-Friendly Option
TEMLite, in contrast, is generally positioned as a cost-effective alternative. While these breakers may display IEC markings, the real-world performance often shows:
- Lower breaking capacities than premium brands
- Less robust materials, leading to shorter operational lifespan
- Quality variation between batches, which affects long-term reliability
- Suitability for general-purpose, light-duty applications, but not continuous high-load EV charging
This doesn’t mean TEMLite is “unsafe,” but in demanding EV charging scenarios, the margin for error is too thin to rely on entry-level breakers.
Should They Be Mixed in the Same Circuit?
While technically possible, mixing Terasaki and TEMLite in the same circuit is strongly discouraged. The reasons include:
- Inconsistent Trip Curves: Different brands calibrate their breakers differently, which can cause poor coordination during faults.
- Weakest-Link Effect: A premium Terasaki breaker paired with a lower-grade TEMLite still leaves the system only as reliable as its weakest component.
- Warranty & Compliance Risks: Many EVSE manufacturers and installers (including us at Innovative Green Power) specify the use of consistent, proven brands to ensure both safety and warranty validity.
A mixed system creates uncertainty — and uncertainty is the enemy of safety in high-load applications like EV charging.
Our Professional Recommendation
For EV charging installations:
- Use consistent, high-quality protection devices from the same manufacturer.
- Ensure MCBs and RCCBs are rated at 10kA breaking capacity or higher.
- Prefer trusted brands such as Terasaki, Lovato, or Hager, which have proven reliability in long-duration, high-load applications.
- Avoid cutting corners on protection systems — the risks far outweigh the cost savings.
At Innovative Green Power, we install Lovato industrial-grade protection components as part of our EV charging systems. Lovato is recognized globally for its 10kA-rated breakers, ensuring superior durability, consistent performance, and the safety margins required for continuous EV charging.
Why Lovato’s 10kA Standard Matters for EV Charging
Most consumer-grade breakers on the market are rated at 6kA. While acceptable for light-duty residential circuits, they can be insufficient for EV charging systems where:
- Short-circuit currents can exceed 6kA, especially in urban and industrial supply networks.
- Continuous high loads accelerate the wear of lower-capacity breakers, shortening lifespan.
- A breaker rated below the fault potential may fail to trip under a real fault, leaving your home and EV charger exposed.
Lovato’s 10kA MCBs are built for high-stress, continuous-load environments like EV charging, giving you:
- Greater fault tolerance
- Longer service life under heavy loads
- Confidence that your system will protect both your family and your EV investment in the event of a fault
This is why at Innovative Green Power, we trust Lovato as one of our go-to brands for EV charging protection.
Final Thought
An EV charger is only as safe as the protection behind it. Using inconsistent or mismatched circuit breakers is like pairing a world-class seatbelt with a budget airbag — the system is only as strong as its weakest part.
Let our obsession with quality protect your safety.
Because when it comes to EV charging and electrical systems, there’s no room for compromise.
