Siemens 6FX3002-5BL03-1CA0 is a pre-assembled brake cable designed specifically for Siemens motion applications. Siemens describes it as a brake cable pre-assembled 2 × 0.75 for SIMOTICS S-1FL6 HI 400 motors used with SINAMICS V70/V90, within the MOTION-CONNECT 300 connection system. It is supplied in a 20 m length, has a straight connector version, and a maximum outer diameter Dmax = 6.3 mm. Siemens also notes an important compliance detail: “No UL for connector on the motor side.”
At a practical level, this product exists to remove variability from brake wiring. A factory-assembled cable helps ensure consistent conductor size, insulation, mechanical strain relief, and connector integrity—exactly the kinds of details that separate a motion system that “works in commissioning” from one that keeps working after months of vibration, maintenance handling, and thermal cycling.
Key Identification and Commercial Data
| Item | Value |
|---|---|
| Manufacturer | Siemens |
| Order number (MLFB) | 6FX3002-5BL03-1CA0 |
| Cable type | Pre-assembled brake cable |
| Connection system | MOTION-CONNECT 300 |
| For use with | SINAMICS V70/V90 and motor S-1FL6 HI 400 (ordering text) |
| Length | 20 m |
| Max outer diameter | 6.3 mm |
| Product family | Pre-assembled signal cables for SINAMICS V90 |
| PLM lifecycle | PM300: Active Product (Industry Mall export) |
| Country of origin | China |
| Commodity code | 85444290 |
| Net weight | 2.624 lb (Industry Mall export) |
| Packaging dimensions | 19.685 × 19.685 × 3.15 in (Industry Mall export) |
| EAN / UPC | EAN 4042948696507; UPC 804766909740 |
| RoHS restriction note | RoHS restriction compliance since 08/03/2016 (Industry Mall export) |
Technical Specifications (Electrical + Mechanical)
| Category | Specification |
|---|---|
| Number of cores / cross-section | 2 × 0.75 mm² |
| Connection type | Straight connector (fixed cable outlet direction) |
| Rated voltage (U0/U, EN 50395) | 30 V / 30 V (power conductors) |
| Test voltage (rms) | 500 V (power conductors) |
| Degree of protection | IP65 |
| Ambient temperature | −25 … +80 °C (operation with permanently installed cable) |
| Cable sheath material | PVC |
| Insulation type | PVC |
| Flame resistance standard | EN 60332-1-1 to 1-3 |
| Oil resistance | EN 60811-2-1 (mineral oil only) |
| Min bending radius (flexible installation) | 155 mm |
| Min bending radius (fixed installation) | 6 × diameter |
| Max number of bends | 1,000,000 |
| Torsional stress | Absolute 30°/m |
| Tensile stress (max) | Flexible: 50 N/mm²; Fixed: 20 N/mm² |
| Compliance notes | “No UL for connector on the motor side” (Siemens ordering text) |
A small but important nuance: one generated technical document lists “UL approval: No” and “CE marking: No.” Meanwhile, Siemens’ own ordering description emphasizes that the motor-side connector has no UL. If your project has strict regulatory documentation requirements, treat this as a cue to pull the official Siemens certificates and regional compliance statements for your exact delivery market and installation context, rather than assuming all approvals automatically apply.
What a Brake Cable Actually Does in a Servo Axis
Many SIMOTICS servo motors include a holding brake whose purpose is to keep the axis from moving when the system is de-energized. In real machines, that typically covers scenarios like:
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preventing vertical axes from dropping when the drive is disabled
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holding a load in place during E-stop or power loss response sequences
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stabilizing mechanical positioning when the axis is at standstill and power is removed
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enabling safer maintenance states when motion power is off
The brake is not “the servo loop.” It’s a separate electromechanical component that needs a clean, reliable electrical connection. A weak connection can produce confusing symptoms: brake release delays, intermittent faults that look like drive problems, or unexpected axis behavior during startup and shutdown. That’s why pre-assembled, application-specific brake cabling exists in Siemens motion ecosystems.
Why a Pre-Assembled Siemens Cable Is Worth It (Even When You Think You Can Build One)
Consistent conductor sizing and predictable voltage behavior
This cable is specified as 2 × 0.75 mm² with defined test and rated voltages. In brake circuits, conductor sizing and insulation quality affect voltage drop, heat, and long-term reliability—especially on longer runs like 20 m, where the “it’s only a brake coil” assumption starts to get punished by physics.
Mechanical life is explicitly engineered
Siemens/technical documentation provides concrete mechanical limits: 155 mm bending radius for flexible routing, 6×D for fixed routing, torsion allowance of 30°/m, and up to 1,000,000 bends. Those aren’t decorative numbers—they are the boundary conditions that keep a cable from becoming a future intermittent fault.
Environmental robustness aligned with industrial reality
With IP65 and an ambient range of −25 to +80 °C for permanently installed cable operation, the part is aimed at real industrial enclosures and machine environments, not office-grade wiring habits. The PVC sheath and insulation, flame resistance standard, and mineral oil resistance note help engineers predict behavior in typical production settings.
Correct connector orientation without improvisation
The product is specified with a straight connector version (fixed cable outlet direction). That sounds minor until you’ve tried to route cables neatly in a crowded cabinet or a tight machine frame where bend radius and strain relief matter.
Application Guidance and Selection Notes
| Engineering concern | Recommendation tied to stated data |
|---|---|
| Tight routing in cabinets or carriers | Respect 155 mm minimum bend radius for flexible installation to prevent conductor fatigue |
| Fixed routing through conduits | Use 6× diameter minimum bend radius in fixed installation |
| High-motion cable carrier use | Validate your bend-cycle expectations against the specified 1,000,000 bends |
| Torsion in rotating axes | Keep torsional load within 30°/m specification |
| Compliance paperwork | Note Siemens statement: no UL for motor-side connector; verify project compliance needs early |
Summary
Siemens 6FX3002-5BL03-1CA0 is a MOTION-CONNECT 300 pre-assembled brake cable engineered for Siemens motion systems using SINAMICS V70/V90 with SIMOTICS S-1FL6 HI 400 motors. It is supplied as a 20 m cable with 2 × 0.75 mm² conductors, a straight connector version, and Dmax 6.3 mm. Its technical profile emphasizes durability and installation predictability: IP65, −25…+80 °C ambient range for permanently installed cable, defined bending/torsion/tensile limits, and documented electrical test data.
