1, Basic definitions of XHHW wire and XHHW-2 wire
1.1 What is XHHW wire?
XHHW cable is an abbreviation for "XLPE High Heat resistant Water resistant", and each letter in its name represents its characteristics:
X - Cross linked polyethylene (XLPE) insulation material
HH - High Heat Resistance
W - Water Resistance
XHHW wire is a type of cable with high heat and humidity adaptability, mainly used in commercial buildings and industrial environments, suitable for dry or humid locations.
1.2 What is XHHW-2 wire?
The XHHW-2 cable has an additional "-2" in naming compared to the XHHW cable, which is the UL standard naming convention for upgraded versions of wires. Similar to XHHW wire, XHHW-2 wire also uses cross-linked polyethylene (XLPE) insulation, but further improves its resistance to mild and humid environments, making it suitable for more demanding working environments.
2, The difference in core technologies between XHHW wire and XHHW-2 wire
The following is a detailed comparison of two types of wires in multiple technical dimensions:
| Compare item | XHHW Wire | XHHW-2 Wire |
| Insulation material | Cross linked polyethylene (XLPE) | Improved cross-linked polyethylene (XLPE) |
| Rated temperature (dry) | 90°C | 90°C |
| Rated temperature (wet) | 75°C | 90°C |
| water resistance | Good | Excellent, suitable for continuous humid environments |
| UL standard | UL44 | UL 44 (Enhanced Testing Standard) |
| Flame retardancy | VW-1, FT1, FT2 | VW-1, FT1, FT2 |
| rated voltage | 600V XHHW wire | 600V XHHW-2 wire, 1000V XHHW-2 wire, 2000V XHHW-2 wire |
| Outdoor laying | Yes, but it is recommended to use protective measures | Can be directly laid |
| Direct burial capability | Need to cooperate with the catheter | Can be directly buried for use |
| Typical applications | Commercial buildings, control circuits | Industrial factories, harsh environments, and humid coastal areas |
3, Comparison of application scenarios for two types of wires
3.1 Application of XHHW wire
XHHW wire are widely used for:
Commercial building power wiring
Industrial Control Circuit
Cable tray or trunking wiring
Dry or moderately humid environment
Advantages: Low cost, suitable for less demanding installation environments.
3.2 Application of XHHW-2 cable
XHHW-2 cable is suitable for more extreme usage scenarios:
Underground direct burial laying (no need for protective pipes)
Continuous humid or corrosive environment
Outdoor exposure installation
Frozen environment (minimum operating temperature can reach -40 ° C)
High corrosion, high humidity, and high temperature places such as power plants and chemical plants
Advantages: Higher temperature resistance, durability, and installation flexibility.
4, Why is XHHW-2 wire more commonly used in modern engineering?
In today's increasingly strict building regulations and complex environmental requirements, more and more projects are using XHHW-2 wires, for reasons including:
Stronger compatibility with specifications: XHHW-2 copper cable meets multiple standards such as NEC, UL, CSA, etc.
Safer: Work more stably in high humidity and high heat environments.
Reduce maintenance costs: Longer lifespan means reduced maintenance frequency and replacement cycles.
Green and environmentally friendly: Some XHHW-2 copper wire have passed ROHS and REACH certification.
5, Comparison and Analysis with THHN/THWN Wire
In many engineering projects, the XHHW series is often compared with the THHN/THWN wire for selection. Below is a brief list of the differences between the four:
| Type | Insulation material | Temperature resistance (humidity) | Can it be buried directly | Usage environment |
| THHN wire | PVC+Nylon Sheath | 75°C
|
No | Indoor/Dry Environment |
| THWN wire | PVC+Nylon Sheath | 75°C-90°C
|
optional | Indoor/humid |
| XHHW wire | XLPE | 90°C
|
Yes | indoor and outdoor |
| XHHW wire | XLPE | 90℃ | Yes | Indoor and outdoor/extreme environments |
6, UL certification and labeling interpretation of XHHW-2 cable
XHHW-2 wires usually have the following markings printed on the insulation surface:
| 600V E545148 XHHW-2 90C DRY/WET XLPE SUN-RESISTANT VW-1 |
The meaning includes:
E545148: UL Certification Number
600V: rated voltage(xhhw 2 600v)
XHHW-2： TYPE IDENTIFICATION
90C DRY/WET: 90 ° C in both dry and wet environments
SUN-RESISTANT： UV resistant, suitable for outdoor use
VW-1： Through vertical flame retardant testing
7, Market prices and procurement recommendations
Generally speaking, the price of XHHW-2 is slightly higher than XHHW wire, about 10% to 20% higher, but considering its longer lifespan, less maintenance, and wider installation adaptability, this investment is worth it.
Procurement suggestion:
Budget limited/indoor engineering: XHHW copper cable is preferred
Outdoor, humid or complex environment: XHHW-2 copper wireis preferred
High long-term durability requirements: choosing XHHW-2 wire is more cost-effective
Still unsure which wire fits your project? Greater Wire Manufacturer has more than 30 years of manufacturing experience, and its products have passed UL, SAA, TUV, and other international certifications. If you have any questions about wires or other questions, please consult us!
