C7 Series Epoxy Sealed DC Contactors – Reliable Solutions for EV Charging, ESS
Epoxy sealed and energy-saving, the C7 series is built for EV charging, storage, and high-voltage DC applications
BSB’s C7 series epoxy sealed DC contactors are engineered for demanding applications such as EV charging stations, energy storage systems (ESS), photovoltaic power setups, and electric forklifts. Featuring high-voltage handling capabilities and durable epoxy encapsulation, these contactors offer superior protection against dust, moisture, and harsh environments. Designed with precision in our cleanroom facility, every unit is built to ensure long-term performance and operational safety. Whether for electric motorcycles, solar storage, or high-current switching needs, the C7 series delivers reliable control with energy-saving PWM economizer technology and wide coil voltage support.
- Epoxy Sealed for Durability
- Wide Coil Voltage Range
- Energy-Saving PWM Economizer
- High-Voltage Handling
- Precision Manufacturing
- Compliant with RoHS standards
- All series are certified by UL, CE, TÜV standards
What is an Epoxy Sealed High Voltage DC Contactor?
Epoxy sealed high voltage DC contactors are designed to ensure reliable switching and long-lasting performance in high voltage environments. BSB’s C7 series uses epoxy resin encapsulation, which is vacuum-cured and nitrogen-filled, providing excellent insulation and protection. This makes them ideal for applications in EV charging, energy storage systems (ESS), and other high-demand systems.
C7 series part number
| Product | Part Number | Amp Rating | Switching Voltage | Coil Voltage Rating | Main Contact Form | Auxiliary Contact / Form | Load Termination | Mounting Type | Coil Characteristic | Certificates |
|---|---|---|---|---|---|---|---|---|---|---|
 | BSBC7-30 | 30A | 1000VDC | 12VDC, 24VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil | UL, CE, TÜV |
| BSBC7-50 | 50A | 1000VDC | 12VDC, 24VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil | UL, CE, TÜV |
 | BSBC7-100 | 100A | 1000VDC | 12VDC, 24VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil | UL, CE, TÜV |
| BSBC7-100 (PWM) | 100A | 1000VDC | 9-36VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil + PWM | UL, CE, TÜV |
 | BSBC7-150 (PWM) | 150A | 1000VDC | 9-36VDC, 32-96VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil + PWM | UL, CE, TÜV |
| BSBC7-200 (PWM) | 200A | 1000VDC | 9-36VDC, 32-96VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil + PWM | UL, CE, TÜV |
| BSBC7-250 (PWM) | 250A | 1000VDC | 9-36VDC, 32-96VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil + PWM | UL, CE, TÜV |
| BSBC7-300 (PWM) | 300A | 1000VDC | 9-36VDC, 32-96VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil + PWM | UL, CE, TÜV |
| BSBC7-350 (PWM) | 350A | 1000VDC | 9-36VDC, 32-96VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical, Horizontal | Single-coil + PWM | UL, CE, TÜV |
 | BSBC7-400 (PWM) | 400A | 1000VDC | 9-36VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical | Single-coil + PWM | UL, CE |
| BSBC7-500 (PWM) | 500A | 1000VDC | 9-36VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical | Single-coil + PWM | UL, CE |
| BSBC7-600B (PWM) | 600A | 450VDC | 9-36VDC | SPST-NO (1 Form A) | SPST-NO, SPST-NC | Male thread, Female thread | Vertical | Single-coil + PWM | UL, CE |
Why Choose BSB’s C7 Series DC Contactor?
The C7 series stands out due to its unique combination of epoxy sealed technology and PWM economizer. The PWM economizer minimizes coil power consumption by rapidly switching the voltage applied to the coil. This results in lower energy consumption and reduces heat generation, extending the lifespan of the contactor. It also features a wide voltage range of 9-36V and 36-95V, allowing users to select the voltage suitable for their design needs, whether it’s 12V, 24V, or even 48V.
How Epoxy Sealed Technology Enhances Reliability
One of the primary reasons epoxy sealed DC contactors are chosen is their ability to prevent the risk of contamination in the contact points. The C7 series is assembled in a cleanroom environment to ensure that no particles are present during production, especially on the contact points, which is often the cause of failure in many DC contactors. This makes the C7 series particularly effective in applications like EV charging and energy storage systems, where reliability and safety are paramount
Internal structure of C7 series contactors
What applications are sealed DC contactors used in?
The C7 series epoxy sealed dc relays are engineered to provide reliable and efficient switching for a wide range of high-voltage applications. In electric vehicle (EV) charging stations, they ensure smooth and safe operation during the charging process by managing the flow of electricity. Their durable epoxy sealing makes them ideal for demanding environments, such as energy storage systems (ESS), where they help regulate the transfer of power between storage units and the grid.
In photovoltaic systems, the C7 dc relays play a critical role in controlling the power distribution between solar panels, storage systems, and the grid, providing reliable protection even under harsh conditions. They are equally effective in electric forklifts and other electric vehicles, where they manage high-current switching, ensuring that operations remain efficient and safe in industrial settings.
The C7 series is also widely used in electric motorcycles, where compact yet reliable high-voltage switching is essential. Moreover, their application extends to UPS systems, where they ensure that power continues to flow seamlessly during grid failures, providing protection for sensitive electronic equipment. In the railway sector, the C7 contactors offer robust performance, maintaining the safety and reliability of electrical systems in trains and railway infrastructure.
These diverse applications demonstrate the versatility of the C7 series, which, thanks to its epoxy sealing technology, delivers long-lasting, efficient performance in everything from EV charging to railway systems, all while reducing the risk of failure from environmental factors like moisture and dust.
EV Charging
Energy Storage
Photovoltaic
Electric Vehicle
Electric Construction Vehicle
High Speed Railway
The contactor shown above is a custom-developed solution.
The PWM economizer is externally mounted at the bottom, which may look unusual—but it’s exactly what the customer wanted, and BSB delivered!
C7 Series Models and Voltage Options
The C7 series epoxy sealed dc contactors are designed to handle a wide range of applications, offering flexible current ratings from 30A to 600A. With the ability to support up to 1000V, the C7 series is well-suited for high-voltage systems in electric vehicle charging stations, energy storage systems, solar power systems, and other industrial applications.
As a leading manufacturer of epoxy sealed DC contactors, BSB is committed to delivering reliable, high-performance products. Leveraging our extensive manufacturing capabilities, we are able to provide competitive pricing without compromising on quality. Our large-scale production allows us to offer highly consistent products and efficient delivery timelines.
In addition, we take pride in our ability to offer customized development services for our customers. Whether you need modifications to meet specific voltage, current, or application requirements, BSB’s engineering team is ready to collaborate with you to create tailored solutions that meet your exact needs.
Frequently Asked Questions (FAQs)
What is the polarity of the main epoxy sealed dc contactors and coil of the C7 series epoxy sealed dc contactors?
The main contacts and coil of the C7 series are non-polarized.
The economizer type of C7 series contactor?
The C7 series contactor uses a PWM-type economizer.
Advantages of choosing a PWM-type economizer contactor?
The PWM economizer works by rapidly switching the voltage supplied to the coil. This switching occurs at a high enough frequency such that the inductance of the coil smooths the current, maintaining sufficient magnetic field strength to keep the contactor engaged while significantly reducing power consumption. Meanwhile, the BSB C7 series contactors support wide coil voltages of 9-36V and 32-95V.
Advantages:
Significantly reduces power consumption.
Reduces heat generation, extending the contactor’s lifespan.
Adapts to wide voltage coils.
What should be considered when choosing a contactor without a PWM economizer?
Contactors equipped with an economizer have a built-in reverse surge absorption circuit, eliminating the need for an external surge protector. For products without an economizer, it is recommended to install a resistor or a TVS diode with a rated voltage 1.5 to 2 times the coil voltage at the coil terminals as a surge protector. Diodes should be avoided, as they may reduce the product’s breaking capacity.
Are BSB C7 series contactors position sensitive?
No. BSB C7 series contactors are not sensitive to position and can be safely installed in any axial direction. However, it is important to note that the product will be used in environments with vibration and mechanical shocks. Over time, areas with high vibration or high impact may affect the overall performance of the relay. At the same time, we also offer contactors with a horizontal mounting option for customers who require it. There will be no performance difference compared to the vertical mounting products.