Introduction
When managing high-voltage DC circuits, selecting the right contactor is essential to ensuring system safety, efficiency, and longevity. This DC Contactor Selection Guide is specifically designed to help you navigate the 👉 full range of BSB DC contactors, offering clear and practical advice based on application needs, technical parameters, and environmental conditions.
At BSB Electric, we specialize in the development and manufacturing of high-performance DC contactors tailored for electric vehicles, energy storage systems, industrial equipment, and more. Our product lines, including the C7, C8, C9, and C10 series, cover a wide range of voltage and current requirements.
Whether you are searching for a compact solution for EV battery systems or a robust contactor for large-scale energy storage applications, understanding the key factors for DC contactor selection will help you choose the most suitable BSB model for your project. This guide will walk you through how to select the right DC contactor, avoid common mistakes, and ensure optimal performance in your specific application.
Understand Key Factors for DC Contactor Selection
Choosing the right DC contactor involves evaluating several key technical parameters. BSB Electric offers a complete range of options across the C7, C8, C9, and C10 series to meet different requirements. Below are the major factors to consider when selecting your BSB DC contactor:
Rated Voltage (Voltage Class)
Ensure that the DC contactor can safely interrupt the maximum system voltage.
For electric vehicle and industrial applications, models rated at 750VDC or 1000VDC are commonly used, such as the BSBC7 DC contactor series and certain models of the BSBC8 DC contactor series.
For energy storage or photovoltaic systems requiring higher voltages, BSBC8P DC contactor series and C10 DC contactor series support up to 1500VDC and 2000VDC or more (C10 series), providing robust solutions for demanding environments and the growing voltage trends in the energy storage industry.
(high voltage DC contactor selection)
Current Rating
Verify that the rated current matches your system’s continuous and peak operating conditions.
BSB’s DC contactors cover a wide range from 10A up to 800A and beyond.
For example, the BSBC8V-300C model offers excellent performance for 300A continuous current in EV drive systems.
Proper DC contactor selection ensures optimal thermal management and operational stability.
Contact Form
Determine whether you need a Normally Open (NO) or Normally Closed (NC) configuration.
BSB offers standard Normally Open (NO) main contacts and selected models with configurable NO or NC auxiliary contacts.
If you are looking for Normally Closed (NC) auxiliary contacts, you may refer to the C7 series contactors.
Mounting Type
Choose between PCB mounting, plug-in, or bolt mounting types based on installation needs.
- PCB-mounted options such as C8-20 to C8-80 and C9 series are ideal for compact battery systems.
- The C8 and C9 series also provides plug-in designs for ease of replacement and field maintenance.
- Bolt-mounted types, like the the C8 series, as well as the C7 and C10 series, offer both stud-type and internal thread-type bolt mounting options, providing greater mechanical stability for large-scale systems.
Sealing Method
Different sealing technologies determine the product positioning and cost.
BSB Electric offers:
- Epoxy resin sealed products (C7 series) for cost-effective industrial applications.
- Ceramic brazed sealed products (C8 and C10 series) for high reliability in EV and higher voltage energy storage systems.
- Open-Type Contactors (C9 Series) for EV and Pre-Charge Circuits.
Choosing the right sealing method is essential for a successful high voltage DC contactor selection.
Application Type
Match the product to the application environment.
- Industrial Applications: BSBC7 Series – 1000VDC, cost-effective and highly flexible. Suitable for EV charging, energy storage systems under 1000V, and low-speed electric vehicle applications.
- Electric Vehicles (EV): BSBC8V series – vibration resistant, compact, 1000VDC rated.
- Energy Storage Systems: BSBC8P Series and BSBC10P Series – 1500VDC and 2500VDC, featuring superior electrical clearance design to support higher voltage energy storage system applications.
This ensures you are selecting a DC contactor optimized for the specific system requirements.
Application-Based DC Contactor Selection
Here is a simplified reference for selecting the right BSB DC contactor based on typical applications:
| Application | Recommended Series | Key Features | Model Pages |
|---|---|---|---|
| Industrial Equipment | BSBC7 Series | 750 to 1000VDC, Epoxy Resin Sealing, Cost-effective | BSBC7 Series |
| Electric Vehicles (EV) | BSBC8V & BSBC9V Series | 1000VDC, Ceramic Sealing, Vibration Resistance | BSBC8 Series, BSBC9 Series |
| Higher Voltage Energy Storage Systems | BSBC8P & BSBC10P Series | 1500 to 2500VDC, Ceramic sealing, High Durability | BSBC8 Series, BSBC10 Series |
Application Notes
- For industrial applications, the BSBC7 DC contactor series offers a balance between cost-efficiency and reliable performance, ideal for DC charging, automation, and backup power systems.
- For electric vehicle applications, the BSBC8V DC contactor series is designed with high vibration resistance and compact structure, suitable for onboard battery systems.
- For energy storage systems, the BSBC8P DC contactor series and BSBC10 DC contactor series provide robust solutions supporting up to 1500VDC and 2500VDC, matching the growing demand for higher voltage platforms.
- For photovoltaic systems, the BSBC8P and BSBC10 DC contactor series ensures excellent arc-extinguishing capabilities and long electrical life even under frequent operation.
Common Mistakes in DC Contactor Selection
Selecting the wrong DC contactor can lead to premature failure, system instability, or even serious safety risks. Here are the most common mistakes to avoid when choosing your BSB DC contactor:
1. Underestimating Voltage Interrupt Capability
It is critical to verify that the DC contactor can safely interrupt the maximum system voltage under both normal and fault conditions.
Choosing a contactor rated below the application’s peak voltage can result in contact welding, insulation breakdown, or catastrophic failure.
Always refer to the rated voltage class and, for high-voltage applications, prioritize products like the BSBC8P DC contactor or BSBC10 DC contactor series designed for 1500VDC and 2500VDC systems.
2. Ignoring Peak Current and Inrush Currents
Focusing only on continuous current ratings while ignoring short-duration peaks is a common mistake.
Certain applications, such as EV traction or battery precharge, generate large inrush currents that can exceed nominal ratings.
When selecting a DC contactor, ensure it can withstand not just continuous loads but also peak surge events without performance degradation.
3. Overlooking Environmental and Installation Conditions
Failing to consider environmental factors such as temperature extremes, humidity, vibration, or dust can shorten contactor life.
In harsh conditions, using a BSB DC contactor with IP67 or IP68 protection and vibration-resistant designs (such as the BSBC8V DC contactor series) ensures stable and reliable operation.
4. Neglecting the Need for Auxiliary Contacts
Many advanced applications require real-time feedback to monitor the contactor’s status (open/closed).
Choosing a model without auxiliary contacts when they are required can complicate system integration later.
BSB offers auxiliary contact options on selected models like the BSBC7-40P DC contactor and BSBC8V-200B DC contactor to meet monitoring needs.
5. Choosing Based Solely on Cost
While cost is an important consideration, selecting a lower-cost DC contactor without verifying performance capabilities can result in higher maintenance costs and unexpected failures.
Investing in a properly rated, reliable BSB DC contactor minimizes total cost of ownership over the system’s life cycle.
Why Choose BSB Contactors?
Selecting a reliable DC contactor is critical for ensuring the long-term stability and safety of your high-voltage systems.
BSB Electric stands out as a trusted partner for your DC contactor selection needs, offering industry-leading quality, performance, and support.
Proven Expertise in High-Voltage DC Contactor Technology
With nearly 30 years of experience in manufacturing low-voltage and high-voltage electrical components, BSB Electric has developed a full portfolio of high voltage DC contactors for electric vehicles, energy storage systems, photovoltaic applications, and industrial automation.
Our BSB DC contactors are designed to meet the rigorous demands of modern applications, combining robust performance with compact designs.
Comprehensive Product Portfolio
BSB offers one of the most complete ranges of DC contactors on the market, covering:
- Rated voltages from 750VDC up to 2000VDC
- Current capacities from 10A to 800A and beyond
- Sealing technologies including epoxy resin, ceramic brazing, and gas-sealed designs
- Mounting options for PCB, bolt-on, and plug-in installations
- Auxiliary contact availability for system monitoring needs
Whether you need a compact BSBC8V DC contactor for an EV battery system or a heavy-duty BSBC10 DC contactor for an energy storage plant, BSB has a tailored solution.
Certified Quality and Reliability
All BSB DC contactors are manufactured under strict quality management systems certified to IATF 16949, ISO 9001, ISO 14001, and ISO 45001 standards.
Our products are rigorously tested for electrical endurance, mechanical durability, thermal stability, and environmental resilience to ensure they perform reliably even in the harshest conditions.
We also offer models compliant with UL, CE, and RoHS standards, supporting international project requirements.
In-House Manufacturing and R&D Capabilities
Unlike many competitors, BSB Electric controls the full production chain—from mold design, injection molding, and stamping to assembly and testing.
This vertical integration enables us to maintain consistent quality, deliver customized solutions quickly, and support innovation in next-generation DC contactor technologies.
Our provincial-level laboratory provides advanced testing capabilities, ensuring that every BSB DC contactor meets or exceeds industry performance expectations.
Dedicated Customer Support
Our experienced sales and engineering teams are ready to provide personalized assistance for your project, from early-stage design consultation to post-sales support.
Whether you require help with selecting a DC contactor, custom modifications, or technical validation, BSB Electric is committed to delivering value and building long-term partnerships.
Conclusion
Choosing the right DC contactor is critical for ensuring the safety, efficiency, and longevity of high-voltage DC systems. This DC Contactor Selection Guide has provided a comprehensive overview of the key factors to consider, common pitfalls to avoid, and the advantages of selecting from BSB Electric’s high-performance product lines.
Whether you are working on an electric vehicle platform, an energy storage system, or an industrial automation project, BSB offers a complete portfolio of DC contactors to meet your specific requirements. For further guidance, technical specifications, or personalized selection assistance, please refer to our full DC contactor application guide or contact our sales team directly.
We are here to help you select the most reliable and efficient BSB DC contactor solution for your application.
Contact BSB Electric today and ensure the success of your next project with the right DC contactor choice!