Shielded Control Cable

85% Tinned Copper Braid Shielding

The defining feature: tinned copper wire braid wrapped helically over the cabled cores at 85 percent geometric coverage density — the industry-standard minimum for effective EMI/RFI suppression up to several MHz. Higher densities (90-95%) available on request for severe noise environments (heavy VFD installations, large motors, radio transmission sites). The tinning prevents long-term braid corrosion in humid environments.

2 to 61 Cores in a Single Cable

Control cables routinely carry 24, 37, or even 61 individual conductors in a single jacketed cable — far more cores than typical 4-core or 5-core power cable. This is the defining selection feature for industrial control wiring: a PLC I/O panel with 24 digital inputs and 12 digital outputs needs a 37-core cable (24+12+1 PE) running back to the field, not 37 individual single-conductor cables. Saves cable tray space, installation time, and material cost.

Clear Core Identification (Numbered or DIN 47100)

High-count multi-core cables need unambiguous core identification at termination time. GB/T 9330 standard: black-with-white-numbers (e.g., “1”, “2”, “3” through “37” printed on each core insulation) plus green-yellow earth. DIN 47100 standard (LiYCY): defined colour sequence with no colour repetition up to 36 cores, then numbered. Misidentified cores at the panel are the most common control cable installation defect — clear ID at the cable level prevents this.

450/750V Insulation, 24V to 230V Operating

KVVP and KYJVP rated 450/750V per GB/T 9330; LiYCY rated 300/500V per DIN VDE 0812. Actual operating circuits typically run at 24V DC (PLC I/O signals), 110V or 230V AC (control circuits, relay coils), or 4-20 mA (analog instrumentation) — the high insulation rating gives generous safety margin and tolerates control circuits that briefly transit through power-conductor voltages during fault conditions or maintenance.

Flame Retardant, Multiple Performance Grades

Standard KVVP per IEC 60332-1-2 (single-cable flame test). For cable-tray installations with multiple cables bundled, specify the ZR-KVVP flame-retardant variant per GB/T 19666 / IEC 60332-3-22 (Category A bundled-cable test). For data centres, hospitals, and underground stations, specify the WDZ-KVVP low-smoke halogen-free variant per GB/T 19666 + IEC 60754 + IEC 61034. Specify the required fire-performance class at order — the production line setup varies.

CCC, VDE, BS, CE Multi-Market Certified

KVVP per GB/T 9330-2020 with CCC certification for the Chinese domestic market. LiYCY per DIN VDE 0812 for the German and European market. YSLCY per DIN VDE 0250-602 for the broader European industrial automation market. BS 5308 for UK and Commonwealth instrumentation applications. CE marking under the Low Voltage Directive available on request alongside the standard certifications. For OEMs supplying global markets, dual or triple certification on a single cable is the norm.

For 4-20 mA, RTD, thermocouple, and other low-frequency analog signals, earth the cable shield at the control room end only — never both ends. Earthing both ends creates a ground loop that circulates mains-frequency current through the shield and injects noise into the signal conductors via mutual coupling. The shield must always be earthed somewhere — a floating shield does nothing. For digital and high-frequency signals, both-end earthing through proper EMC glands is the correct approach.

If you have to splice or junction a shielded cable, the shield must be carried through the splice with the same coverage density as the cable itself — otherwise the splice becomes an EMI “antenna” that injects noise into the cable downstream. Use proper shielded junction boxes with 360-degree EMC glands at entry and exit. The most common installation defect is “pigtail” shield connections at panel entries, where the shield is wrapped into a small wire that’s screwed to a terminal — this works for low-frequency installations only.

Even shielded control cables benefit from physical separation from power cables in cable trays — the shield reduces but does not eliminate induced noise. Industry standard practice: control cables in their own dedicated cable tray, or separated by at least 200 mm from power cables in shared trays, with at least 50 mm vertical separation. If they must cross, do so at 90 degrees to minimise inductive coupling. The cable tray itself should be metal and properly earthed — concrete or plastic trays defeat the EMC benefits.

KVVP minimum bending radius is 12× OD per GB/T 9330 (or 6× OD for the flexible KVVRP and LiYCY variants). Tighter bends during cable pulling permanently damage the braid shield — individual braid wires fracture, gaps open up in shield coverage, and the cable’s EMC performance drops drastically. The damage is invisible from outside but shows up as intermittent signal noise weeks or months later. Use proper cable rollers at corners during installation, not manual pulling around tight bends.

Multi-core control cables routinely have 24, 37, or 61 individual conductors — field troubleshooting becomes nearly impossible without clear labelling. Industry practice: heat-shrink cable ID labels at both ends of every cable run; individual core ferrule sleeves printed with the I/O function (e.g., “PT-101 +” for pressure transmitter loop power positive); cable schedule documentation maintained in the project handover package. The labelling effort during installation pays back many times over in maintenance and modification work later.

Test insulation resistance (megger test at 500V DC) between every core and earth, and between adjacent cores, before energising the cable. Expected reading is > 100 MΩ for new cable; readings below 10 MΩ indicate water ingress, damaged insulation, or installation faults that will cause signal problems in service. Document the megger test results in the project handover — the baseline values are useful for comparison during future maintenance to detect insulation degradation. Repeat the test after one year of service for high-criticality installations.