What is an Armored Frequency Converter Cable?
Armored inverter cables are specifically designed for power transmission between inverters and motors, suppressing electromagnetic interference (EMI), bearing current, and reflected voltage generated by high-frequency harmonics of the inverter.
The difference between armored inverter cables and ordinary inverter cables lies in the addition of an armor layer (steel tape or steel wire armor), providing mechanical protection and making them suitable for direct burial, cable trenches, or environments susceptible to external damage.
Common Standards:
Domestic: GB/T 12706, JB/T 8734
International: IEC 60502, UL 1277 (TC-ER rating)
Structure of Armored Inverter Cables
Armored inverter cables employ a symmetrical structural design, consisting of:
1. Conductor — Multi-strand finely stranded tinned copper wire (Class 5 flexible conductor), common cross-section 4-300mm².
2. Insulation — XLPE (cross-linked polyethylene), temperature resistant 90℃ or 105℃.
3. Grounding Core — Three symmetrically distributed grounding cores (3+3 structure) to reduce bearing current.
4. Shielding — Copper tape/copper wire braided + aluminum foil composite shielding, shielding rate ≥85%.
5. Inner Sheath — PVC or LSZH.
6. Armor Layer — Double steel tape armor (STA) or steel wire armor (SWA).
7. Outer Sheath — PVC, LSZH, or special oil-resistant material.
Armored frequency converter cable parameters
| Parameter categories | Specific parameters | Technical indicators | Notes |
|---|---|---|---|
| Electrical performance | Rated voltage | 0.6/1kV, 1.8/3kV, 3.6/6kV | The 0.6/1kV version is a general-purpose version, suitable for most industrial applications; the higher voltage level is compatible with large-scale frequency converters. |
| DC resistance of conductor | At 20℃, ≤0.017241Ω·mm²/m (1.5mm²) | Made of oxygen-free copper, conforming to GB/T 3956 standard. | |
| Insulation resistance | ≥1000MΩ·km (90℃) | Cross-linked polyethylene insulation possesses excellent electrical insulation properties. | |
| withstand voltage performance | 3.5kV/5min without breakdown (0.6/1kV level) | Finished cables must pass a power frequency withstand voltage test. | |
| Capacitor imbalance | ≤0.5nF/100m | Symmetrical structural design reduces electromagnetic interference | |
| Mechanical properties | Armor layer material | Galvanized steel strip/galvanized steel wire | Steel strip armor is suitable for fixed installation, while steel wire armor has stronger tensile strength. |
| Armor layer thickness | Steel strip 0.3-0.8mm, steel wire 1.0-2.0mm | Select based on cable cross-section and application scenario. | |
| compressive strength | ≥1000N/100mm (steel belt armor) | Resisting external mechanical compression and crushing by heavy objects | |
| Bending radius | Fixed installation ≥15D, mobile installation ≥20D (D is the outer diameter of the cable) | Avoid armor layer cracking and insulation damage | |
| Environmental performance | Conductor long-term operating temperature | 90℃ | Short-term overload tolerance: 130℃ |
| maximum short circuit temperature | 250℃ (duration ≤ 5 seconds) | Compliant with GB/T 12706 standard | |
| Ambient temperature for laying | ≥-10℃ (fixed installation), ≥0℃ (mobile installation) | For low-temperature environments, it is recommended to use a cold-resistant outer sleeve. | |
| Flame retardant properties | GB/T 19666-2005 Class B (ZR type) | Low-smoke halogen-free conforms to GB/T 31247-2014 standard. | |
| Structural parameters | Conductor structure | Category 5 soft stranded copper wire | Multiple strands of fine filaments twisted together, resulting in good flexibility. |
| Insulation thickness | 0.7-4.5mm (depending on voltage rating) | Cross-linked polyethylene insulation with excellent corona resistance | |
| Shielding structure | Copper wire braiding + copper strip wrapping composite shielding | Shielding coverage ≥90%, effectively resisting electromagnetic interference. | |
| Outer sheath thickness | 1.5-5.0mm (depending on cable cross-section) | Low-smoke halogen-free polyolefin or polyvinyl chloride materials |
Three Core Advantages of Armored VFD Cables:
Superior Electromagnetic Compatibility (EMC): Inverters generate significant high-frequency noise. The armor layer, combined with the shielding layer, effectively prevents interference with surrounding sensors and control signals.
Strong Mechanical Protection: No additional conduit required; pressure-resistant, impact-resistant, and rodent-proof, significantly reducing installation costs and maintenance frequency.
Environmental Adaptability: Resistant to chemical corrosion, ultraviolet radiation, and extreme temperature differences.
Common Model Classifications:
Commonly used models in China (BP Series):
BP-YJVP2-22: Cross-linked polyethylene insulated, PVC sheathed, copper tape shielded, steel tape armored inverter cable.
BP-YJVP3-22: Aluminum-plastic composite tape shielded, steel tape armored inverter cable.
BP-YJV-32: Copper wire shielded, steel wire armored inverter cable (suitable for applications with high tensile strength).
ZR-BPYJVP2-22: Flame-retardant armored inverter cable.
Commonly Used Models in International/American Standards:
VFD-AIA (Aluminum Interlocked Armor): Aluminum interlocked armored frequency converter cable (common in North America).
VFD-SWA (Steel Wire Armor): Steel wire armored frequency converter cable (common in European/British standards).