VFD Cable (Variable Frequency Drive Cable / Frequency Converter Cable)

1. Product Introduction

VFD cables are dedicated power cables for variable frequency drive systems, marked with series code BP, with standard rated voltage 0.6/1kV. They connect frequency converters and variable frequency motors. The high-speed switching of IGBT modules inside inverters generates steep pulse voltage, high-frequency harmonics, common-mode voltage and electromagnetic radiation. Conventional YJV power cables cannot withstand pulse surges or suppress EMI, which easily causes bearing electroerosion, insulation breakdown, disturbance to surrounding instruments, excessive motor noise and other failures. Designed with three core technologies: symmetrical 3+3 core layout, corona-resistant XLPE insulation and double composite shielding, VFD cables absorb voltage spikes, return common-mode current and block harmonic radiation to meet strict EMC requirements. Complying with national cable standards, equivalent to IEC 60228 and VDE 0250 international specifications, they are widely deployed in industrial transmission, water pumps & fans, metallurgy, mining, crane machinery, papermaking and textile variable speed systems.

2. Model Definition & Common Types

Code Explanation

BP = VFD dedicated cable; YJ = XLPE cross-linked polyethylene insulation; V = PVC sheath; P = overall copper braided shield; TP2 = copper tape wrapped + copper braided composite shield; R = flexible conductor; ZR = flame retardant; WDZ = LSZH low smoke zero halogen Main mainstream models:

1. BPYJV: Basic symmetrical VFD cable without shield, for mild interference environments

2. BPYJVP: Copper braided overall shielded VFD cable, universal type for general industrial conditions

3. BPYJVTP2: Double composite shield (longitudinal copper tape + copper braid), preferred for complex environments with strong electromagnetic interference and high EMC requirements

4. BPYJVP12R: Flexible double shielded VFD cable, for equipment requiring repeated bending and cable chain movement

5. BPGGP: Silicone rubber insulated high-temperature resistant VFD cable, applied to high-temperature ovens and metallurgical workshops Core configuration: Standard symmetrical 3+3 cores (3 phase conductors + 3 equal-section PE earthing cores); optional 3-core / 3+1-core layouts; common cross-sections: 1.5mm² ~ 240mm²

3. Internal Structure (Inner to Outer)

1. Copper ConductorClass 2 compact stranded oxygen-free copper for fixed installation; Class 5 fine stranded tinned flexible copper for frequent bending and cable chain applications. Enlarged conductor surface area mitigates high-frequency skin effect, reducing high-frequency impedance and heat loss.

2. XLPE Insulation (Core for Pulse Resistance)Low dielectric constant cross-linked polyethylene with outstanding corona resistance and resistance to high-frequency pulse voltage shocks. It suppresses reflection of steep dv/dt voltage spikes; thicker optimized insulation withstands cyclic high-frequency electrical stress and delays insulation cracking & aging.

3. Symmetrical 3+3 Cabling StructureThree phase conductors twisted uniformly with three earthing cores of identical cross-section. This layout counteracts odd-order harmonics, balances loop inductance and capacitance, and provides a low-impedance return path for high-frequency common-mode current. It fundamentally reduces shaft voltage and prevents motor bearing electrocorrosion, the key difference from ordinary 4-core power cables.

4. Double Composite Shield System (EMC Core)Inner layer: Longitudinal wrapped copper tape with 100% coverage to block low-frequency common-mode coupling interference; Outer layer: Tinned copper braided shield (coverage ≥85%~90%) to attenuate high-frequency harmonics ranging 1~30MHz; Both cable ends shall be grounded properly to form a complete shielding loop, preventing EMI intrusion into peripheral PLCs, sensors and intrinsic safety circuits.

5. Inner Cushion LayerPVC / LSZH polyolefin material, separating shield and outer sheath to buffer mechanical compression.

6. Outer SheathStandard black wear-resistant PVC sheath; nitrile rubber for oil, acid & alkali corrosive environments; LSZH sheath for enclosed fire-protection spaces; UV-resistant PVC for outdoor weather-resistant applications.

4. Key Technical Parameters

1. Rated voltage: 0.6/1kV

2. Continuous operating temperature: 90℃ (XLPE); 180℃ (silicone rubber); short-circuit withstand temperature: 250℃ (max 5 seconds)

3. Minimum laying temperature: 0℃; cold-resistant version down to -40℃

4. Minimum bending radius: ≥10 times cable OD for fixed laying; ≥15 times OD for flexible cable chain routing

5. Power frequency withstand voltage: No insulation breakdown after 5 minutes under 3.5kV

6. Shielding effectiveness: ≥45dB attenuation at 1MHz, blocking most electromagnetic radiation generated by inverters

5. Core Performance Advantages

1. Excellent pulse voltage endurance, extended insulation service life Thickened corona-resistant XLPE insulation absorbs steep voltage spikes from inverters and suppresses superimposed voltage reflection, avoiding premature breakdown of motor winding insulation; service life is more than twice that of conventional power cables.

2. Symmetrical 3+3 design eliminates bearing electroerosion Balanced earthing cores discharge common-mode voltage and lower shaft voltage, thoroughly resolving abnormal noise, wear and premature failure of VFD motor bearings, cutting equipment maintenance costs.

3. Double composite shielding delivers superior EMC performance Hierarchical suppression of low & high frequency interference: it avoids outward harmonic radiation disturbing PLCs, sensors and IS instruments, meanwhile resisting EMI from large peripheral equipment to guarantee stable operation of industrial control systems.

4. Lower heat generation & higher current carrying capacity Optimized conductor structure weakens skin effect, producing less heat under high-frequency operation with better heat dissipation for densely laid cable trays.

5. Wide environmental adaptability Optional flame retardant, LSZH, high-temperature resistant, oil-proof and cold-resistant sheaths are available to adapt to harsh conditions including high-temperature workshops, outdoor sites, underground trenches and oily metallurgical plants.

6. Application Scenarios

1. General Industry: Variable frequency drive systems for water pumps, fans, central air conditioning compressors and air compressors;

2. Heavy Industry: Metallurgical rolling mills, mine winches, overhead travelling cranes and steel production line variable frequency transmission equipment;

3. Light Manufacturing: Servo & VFD equipment for papermaking, textile, printing and packaging production lines;

4. Special Working Conditions: Reciprocating cable chain equipment, high-temperature heat treatment workshops and port lifting machinery;

5. Municipal & Building: Ventilation & smoke exhaust systems in subways and central air conditioning power distribution for large shopping malls.