Detailed Description
What Is General Purpose Electrical Wire?
General purpose electrical wire is a single-core insulated conductor used for the internal wiring of electrical and electronic equipment — it is the wire that connects terminal A to terminal B inside a control panel, an appliance, a power supply, or an electronic assembly. Unlike building wiring cable (which is pulled through conduit and fixed in place), general purpose wire is handled by equipment assemblers — it is cut to length, stripped, crimped or soldered, and routed through equipment chassis, wire ducts, and cable ties.
The wire is defined by two distinct international standards families:
- IEC 60227 (and harmonized HD 21): Covers PVC insulated single-core wires for equipment wiring at 300/500 V (light duty, ≤1 mm²), 450/750 V (standard), and the associated temperature ratings (70°C TI1, 90°C TI2). The designations RV, H05V-K, and H07V-K are the IEC equipment-wire types.
- UL 1581 / UL 1007 / UL 1015 / UL 1569: Cover recognized component wire for the North American market. UL 1007 is 300 V / 80°C, UL 1015 is 600 V / 105°C, UL 1569 is 300 V / 105°C. These are the standard wires inside every UL-listed industrial control panel, appliance, and electronic product sold in North America.
Conductor Class Selection — Solid, Stranded, or Flexible?
| Conductor Class | IEC Designation | Flexibility | Typical Application | Termination Method |
|---|---|---|---|---|
| Class 1 (Solid) | BV, H07V-U | Rigid | PCB insertion, wire-wrap, automated harness assembly | Solder, wire-wrap, screw clamp (no ferrule needed) |
| Class 2 (Stranded) | BVR, H07V-R, UL 1015 stranded | Semi-flexible | Control panel point-to-point wiring ≥2.5 mm² | Screw clamp, crimped lug, spring clamp |
| Class 5 (Flexible) | RV, H07V-K, UL 1007/1569 | Flexible | Equipment door hinges, moving harnesses, tight routing | Ferrule + screw clamp, crimp terminal |
Class 5 flexible conductor is the most common for general equipment wiring because it combines good current-carrying capacity with the flexibility needed to route wires neatly inside equipment enclosures. The fine stranding (single wire diameter 0.20–0.41 mm depending on cross-section) allows tight bends without conductor damage. For cross-sections of 10 mm² and above in control panels, Class 2 stranded is typically used because the conductor is stiff enough to hold its shape after forming, which keeps the panel wiring neat and serviceable.
UL vs IEC — Voltage and Temperature Designations Compared
| Parameter | IEC 60227 (RV/H07V-K) | UL 1015 | UL 1007 |
|---|---|---|---|
| Rated voltage | 300/500 V (≤1 mm²); 450/750 V (≥1.5 mm²) | 600 V | 300 V |
| Temperature rating | 70°C (TI1) or 90°C (TI2) | 105°C | 80°C |
| Flame test | IEC 60332-1-2 | UL VW-1 (vertical flame) | UL VW-1 |
| Conductor | Class 1, 2, or 5 bare copper | Stranded or solid bare/tinned copper | Stranded bare/tinned copper |
| Cross-section range | 0.5–120 mm² | AWG 20–4/0 (0.52–107 mm²) | AWG 20–16 (0.52–1.31 mm²) |
| Primary market | Europe, Asia, IEC countries | North America, global OEM | North America, electronics |
An important practical distinction: UL 1015 at 600 V and 105°C is the most versatile single specification — it meets or exceeds the voltage and temperature requirements of most equipment internal wiring applications. If a design must use a single wire type across all internal connections, UL 1015 (with IEC 60227 compliance verified) is the recommended specification. For high-density, low-voltage wiring where space is the primary constraint (e.g., dense control panels with thousands of terminations), UL 1007 or IEC H05V-K thin-wall construction reduces the wire cross-section without compromising safety.
Practical Considerations for Equipment Wiring
- Ferrules (cord end terminals): Flexible (Class 5) conductors terminated in screw-clamp terminals should always be fitted with a ferrule — a thin-walled copper tube crimped over the stripped conductor end. The ferrule contains the individual fine strands, prevents them from splaying when the screw is tightened, and protects them from damage. Ferrules are color-coded by cross-section per DIN 46228
- Stripping length: The insulation strip length must match the terminal depth. For screw-clamp terminals, the stripped length should be the terminal depth plus 0.5–1.0 mm — enough for full conductor insertion without exposed copper outside the terminal. For ferrules, the strip length equals the ferrule barrel length
- Wire marking: Every wire in a control panel or equipment assembly should be identified at both ends. Wire markers can be heat-shrink sleeves, clip-on numbered rings, or printed labels. The identification must remain legible for the service life of the equipment — ink that fades or adhesive that fails after years of operation defeats the purpose of wire identification
- Bundling and ampacity de-rating: When multiple wires are bundled together inside a wire duct, the mutual heating reduces each wire's ampacity. Per IEC 60364-5-52, a bundle of 5–7 current-carrying wires requires a de-rating factor of approximately 0.6. A 2.5 mm² wire rated 25 A in free air becomes a 15 A wire when part of a 7-wire bundle. Panel designers must account for this de-rating when sizing wire cross-sections in high-density wiring ducts
- Temperature derating: PVC insulation has a maximum continuous conductor temperature rating that must not be exceeded. The actual conductor temperature in operation is the sum of the ambient temperature inside the equipment enclosure plus the temperature rise from I²R heating in the conductor. For equipment with internal ambient above 40°C, the wire ampacity must be de-rated or a higher temperature class insulation (105°C or silicone) specified
Why Choose Yichi General Purpose Electrical Wire
- Dual IEC + UL compliance from a single source: Yichi wire is manufactured and tested to IEC 60227 and UL 1007/1015/1569 standards, supported by UL recognized component listings. One wire part number for global equipment builds — no dual sourcing for different markets
- Full conductor spectrum: Class 1 solid, Class 2 stranded, and Class 5 flexible conductors in metric (0.5–120 mm²) and AWG (20–4/0) sizes — the complete range for any equipment wiring specification
- 105°C PVC as standard for UL 1015: The 105°C insulation rating provides margin for equipment internal temperature rise and allows more ampacity per conductor cross-section compared to 70°C or 80°C PVC — a smaller wire can carry the same current, reducing panel weight and wiring duct fill
- 100% in-line spark testing: Every meter of wire is spark-tested at 6–10 kV AC during production — not a sample test. Any pinhole or thin spot in the insulation is detected and the wire is cut out before it reaches the packaging reel
- UL recognized component — simpler equipment certification: When your equipment uses UL recognized wiring (UL 1007/1015/1569), the wire is accepted without additional testing during the UL end-product listing process. We provide the UL file number and test data for your certification submission
- Custom color coding, striping, and printing: Standard solid colors or custom color codes for complex harness builds; longitudinal stripe for multi-color identification; sequential meter marking on request for cut-to-length manufacturing in harness production lines