THHN/THWN wire is a single-conductor copper building wire with PVC insulation and a nylon outer jacket, designed for electrical power distribution in various installations.
• Voltage rating: 600 volts
• Temperature rating:
o 90°C (dry locations – THHN)
o 75°C (wet locations – THWN)

Stranded Wires (Medium Sizes)
Medium-size stranded wires are larger than small sizes and are commonly used for higher current loads.
• Typical range: 8.0 mm² to 30 mm² (approx.)
• Constructed from multiple copper strands twisted together (Class B stranded)

Key Features:
• Moderate flexibility (less flexible than small sizes but easier to handle than large conductors)
• Designed for higher ampacity applications
• Stronger mechanical structure for longer conduit runs
• Easier pulling compared to solid conductors of the same size

Construction:
• Conductor: Annealed copper, stranded
• Insulation: Heat-resistant PVC
• Outer Jacket: Nylon coating for:
o Abrasion resistance
o Protection against oil, gasoline, and chemicals
o Smooth surface for easy conduit installation

Typical Applications:
Medium-size THHN/THWN stranded wires are commonly used in:
• Feeder lines for panels and subpanels
• Distribution circuits in residential and commercial buildings
• Motor and equipment connections
• Industrial power systems
• Installation in conduits, raceways, and cable trays

Summary:

THHN/THWN 600V 90°C stranded wire (medium size) is a durable, moderately flexible copper conductor designed for carrying higher electrical loads in building wiring systems, offering strong insulation, heat resistance, and protection for reliable performance.