Product Introduction
The BSB C7-150A DC contactor is a robust 150-amp high-voltage DC contactor engineered for demanding switching operations in electric vehicles (EVs), energy storage systems (ESS), and photovoltaic equipment. Featuring a fully epoxy-sealed design, this model provides exceptional reliability in high-vibration and high-temperature environments. With a max switching current of 1500A and an ultra-low contact resistance of just 0.2 mΩ, the C7-150A is built for heavy-duty, long-life performance.
Product Features
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Ultra-Low Resistance: Main contact resistance as low as 0.2 mΩ @150A, ensuring high efficiency and low heat.
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High Switching Capability: Rated for 150A continuous and up to 1500A switching current at 320VDC.
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Reinforced Structure: M8 external threads and 10–12 N·m torque for heavy load environments.
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Flexible Coil Options: Supports 12/24V and 48/72V coil voltages, ideal for both standard and high-voltage systems.
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Optional Auxiliary Contacts: NO, NC, or changeover types available.
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Certified Reliability: UL, CE, TUV, and RoHS compliant, designed to meet stringent industry standards.
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Environmental Durability: -40°C to +85°C operation, vibration resistance up to 20G, IP67-rated enclosure.
Typical Applications
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High-voltage bus switching in electric commercial vehicles (EVs and buses)
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Battery energy storage systems requiring high inrush capabilities
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High-power photovoltaic inverters
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DC charging infrastructure and converters
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Military-grade or off-road EVs with shock and vibration exposure
Summary of Technical Parameters
| Parameter | Value |
|---|---|
| Rated Current | 150A |
| Rated Voltage | 12–1000VDC |
| Main Contact Type | SPST-NO (1SH) |
| Contact Resistance | ≤0.2 mΩ |
| Max Switching Current | 1500A @ 320VDC |
| Dielectric Strength | AC 3000V |
| Insulation Resistance | ≥1000 MΩ @ 1000VDC |
| Mechanical Life | 300,000 cycles |
| Capacitive Load Life | 360A (RC=1ms), 50,000 cycles |
| Operating Temperature | -40°C to +85°C |
| Coil Voltage Options | 12/24VDC or 48/72VDC |
| Auxiliary Contact (Optional) | NO / NC / Changeover / None |
| Mounting Orientation | Vertical / Horizontal |
| Weight | ~425g–430g depending on configuration |
| IP Rating | IP67 |
| External Conductor Area | ≥50 mm² |
Dimensional Drawing & Wiring Diagram
Vertical type with economizer
Horizontal type with economizer
FAQs About The BSBC7-150A DC Contactor
Q1: Does the C7-150A DC contactor have reverse surge protection?
A1: Only products equipped with a PWM economizer include a surge suppression circuit. If you choose a standard product without an economizer, you need to address the issue of counter-electromotive force (back EMF) from a design perspective.
Q2: Does the C7-150A DC contactor support auxiliary contacts?
A2: Yes. Optional configurations include normally open (NO), normally closed (NC), and changeover (Z-type) auxiliary contacts.
Q3: What’s the minimum conductor size recommended?
A3: At least 50 mm² for safe, low-resistance current flow.
Precautions for Use
To ensure long-term safety and optimal performance of the C7-150A high voltage DC contactor, please follow these important guidelines:
Mechanical Installation
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Use spring washers during installation to prevent screw loosening.
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Tighten mounting screws with a torque of 2.5–3.5 N·m. Over-tightening may lead to damage.
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Do not use the contactor if it has been dropped or mechanically impacted, even if no visible damage is found.
Wiring and Polarity
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Main contacts and control coil leads are non-polarized, meaning installation is flexible and there is no requirement for terminal polarity.
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Ensure clean, secure connections at the main terminal.
Avoid contamination with dust, grease, or foreign matter, which may cause terminal overheating.
Coil Surge Protection
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Models with economizer include a built-in reverse surge protection circuit—no external protection is required.
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For models without economizer, install a TVS diode or varistor rated at 1.5–2× the coil voltage across the coil terminals.
⚠️ Do not use diodes, as they reduce the contactor’s breaking capacity.
Environmental and Installation Conditions
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Ambient operating temperature: –40°C to +85°C
The sealed internal chamber contains gas, and higher ambient temperature accelerates gas diffusion, which shortens the product’s life. -
Avoid installing near strong magnetic fields (e.g., transformers, magnets) or heat-emitting components (e.g., fuses, shunt resistors).
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If installation near heat is unavoidable, perform a temperature rise test to verify thermal safety.
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Altitude limit: ≤4000m
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IP rating: IP67 (sealed)
Switching and Circuit Design
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Do not exceed rated switching life or current capacity.
The contactor may lose disconnection capability at end-of-life.
➤ It is strongly recommended to design the circuit to cut off power within 1 second if the contactor fails. -
For resistive loads, rated current and voltage can be directly applied.
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For inductive loads (L/R > 1ms), a parallel surge suppressor (e.g., TVS or varistor) must be installed.
Coil Drive Requirements
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If the contactor is repeatedly energized and de-energized at full load and rated voltage, coil temperature will rise, increasing resistance and required pull-in voltage.
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In such cases, consider:
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Reducing load current
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Limiting continuous “on” time
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Using a coil voltage slightly higher than the rated pickup voltage
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The coil drive circuit must provide sufficient power (≥ coil rated power). Otherwise, cut-off performance may deteriorate.
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In economizer models, the coil switches to holding power mode approximately 0.1s after energizing.
Do not attempt to switch off at exactly this moment, as it may damage the coil.