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News Release

Release of High Voltage Contactor with the Highest Current Overload Capacity in the Industry

  Tokyo, May 24, 2017 - Fuji Electric Co., Ltd. (TSE:6504) (“FE”), headquartered in Tokyo, Japan, led by President Michihiro Kitazawa, is pleased to announce the release of a High Voltage Contactor capable of delivering the highest current overload capacity in the industry for more reliable vehicle operation.


Electric and hybrid vehicles are becoming increasingly popular around the world. Because these next-generation automobiles are equipped with high-voltage, high-capacity batteries, maintaining and improving their safety is a critical concern. Meanwhile, automakers are demanding more compact, lightweight vehicle body structures to help boost fuel efficiency and extend cruising range.

Conductors are devices that open and close the electrical circuits that link the battery to the inverter and the motor. Fuji Electric forecasts that global market for automotive contactors would grow at least 30% a year and sales would reach at least JPY 70 billion by 2020.

Now, taking advantage of the first-rate technical expertise and business performance in industrial power distribution and control devices that we have achieved in Japan, we have successfully developed a new automotive contactor capable of delivering the highest withstand capability (maximum allowed current/time) in the industry. This latest device is one of many that we will gradually be adding to our expanded contactor lineup.

Our Fukiage Plant in Kounosu, Saitama Prefecture is equipped with Japan’s leading short-circuit breaking test equipment. This gives us the ability to better support customer product development, since we are able to carry out high-current short-circuit withstand capability tests and breaking tests for battery charge/discharge circuits that include our High Voltage Contactor.

2.Product Features

1) Unique contact structure greatly improves safety

When a vehicle breaks down or gets into an accident that results in a short circuit and overcurrent, magnetic forces (electromagnetic repulsion) cause the contact of the contactor to be lifted, which may generate a massive arc (discharge phenomenon) of several thousand or even several tens of thousands of amperes. Our High Voltage Contactor, however, features a unique contact structure that compensates electromagnetic repulsion-allowing it to deliver an industry-leading 20,000 amperes of withstand capability. The result is a contactor with significantly reduced risk of rupture and/or fire.

2) Sealed contact block for better safety and more compact design

Although an arc is generated when the circuit is interrupted (when contact points open), the structure of the High Voltage Contactor features sealed contact block that prevent sparks from the arc from shooting out of the device while also preventing dust contamination. We’ve also enclosed a gas that boosts breaking performance within the sealed contact block, making distance required for electrical interruption shorter than it would be with an air circuit breaker and allowing for the kind of compact design required in today’s automotive applications.

3) Makes circuit design customization easier

Magnetic force from a permanent magnet installed in contactors lengthen arcs generated during breaking in order to extinguish them, but in the past, there was an issue with these devices having different breaking performance depending on the direction of the current (charging vs. discharging). We’ve been able to achieve equal breaking performance in both directions with design that improves permanent magnet configuration, for example. This brings flexible installation to battery charge/discharge circuits, which in turn allows for easier circuit design customization.



  • • Next-generation automobiles (e.g. electric vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles)
  • • Transportation equipment mounted with secondary batteries (e.g. forklifts, construction equipment, automated guided vehicles)

4.Timing of Release

The date of this announcement

5.Product Specifications

Model SVE135
Rated current/voltage 135A / 450VDC
Breaking performance 400A / 450VDC (50 times)
Current overload capacity 20kA, 50ms
Main circuit polarity None (equal breaking performance in both directions)
Dimensions (mm) WxHxD 48.3×104×86
Weight (g) 650

6.Product Inquiries
  Operation Department, Business Planning Group, Fuji Electric Co., Ltd.
  Telephone: +81-3-5437-7161

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