1.What Is SIS Switchboard Wire?
SIS type wire, or Switchboard Instrumentation Style wire, is a single-conductor, low-voltage electrical wire designed for internal panel and switchboard wiring. Its structure typically includes:
Conductor: Annealed copper for excellent conductivity
Insulation: Heat-resistant SIS wire insulation, most commonly made from XLPE (cross-linked polyethylene)
Voltage Rating: 600 volts
Temperature Rating: 90°C in dry locations
Standards: UL 44, CSA C22.2 certified
This wire is engineered to provide high thermal and dielectric strength, making it ideal for confined, high-load electrical spaces.
2.Key Features and Benefits of SIS Switchboard Wire
SIS type wire offers several key advantages that make it suitable for critical electrical systems:
Excellent Thermal Stability
The XLPE SIS wire insulation withstands high temperatures without performance degradation.
Strong Mechanical and Flexibility Properties
Easy to install, even in tight or complex routing situations.
Resistance to Chemicals and Abrasion
Durable insulation protects against oils, solvents, and harsh environments.
Flame-Retardant
Meets UL 44 flame test requirements, enhancing overall fire safety.
Clear Color-Coded Options
Multiple insulation colors help with fast identification during installation and maintenance.
3.Common Applications of SIS Switchboard Wire
Thanks to its performance and certification, SIS switchboard wire is widely used in:
Industrial control cabinets and switchgear
Power distribution systems in commercial buildings
Solar power control panels and battery systems
OEM electrical equipment internal wiring
It is particularly valuable where space is limited and operating temperatures are high.
4.SIS Type Wire vs. Other Common Wire Types
How does SIS type wire compare with THHN, MTW, or XHHW wiring?
| Feature | SIS Switchboard Wire | THHN | MTW |
|---|---|---|---|
| Insulation | SIS wire insulation (XLPE) | Nylon/PVC | PVC |
| Temp Rating | 90°C (dry) | 75–90°C | 60–90°C |
| Environment | Panels, switchboards | Conduit wiring | Machine wiring |
| Flexibility | Moderate to High | Moderate | High |
SIS wire is preferred in applications requiring flame resistance, thermal endurance, and insulation reliability over long periods.
5.How to Choose the Right SIS Switchboard Wire
When selecting SIS type wire, consider the following:
Current Load vs. Wire Gauge
Select the appropriate AWG size based on your system's current needs.
Installation Environment
For high-temperature or chemically exposed areas, XLPE SIS wire insulation is ideal.
Compliance and Certifications
Ensure the wire is UL or CSA listed and meets local electrical codes.
Color Coding
Choose standard wire colors to simplify maintenance and troubleshooting.
Working with a trusted wire and cable manufacturer will help ensure proper selection for your specific project.
6.Where to Buy High-Quality SIS Switchboard Wire
When sourcing SIS switchboard wire, choose a reliable supplier that offers:
UL, CSA, and RoHS-compliant products
Various AWG sizes and color options
Custom lengths and packaging
Technical support and documentation
Working with certified manufacturers ensures product consistency, compliance, and long-term performance.
Dongguan Greater Wire & Cable Co., Ltd. provides customers with cables of various materials and structures, including cross-linked cables, PVC cables, rubber cables and silicone cables, to meet the needs of different scenarios. We understand that every detail determines the performance of the cable, and we also understand your expectations of a partner. If you have any procurement needs or technical questions, please feel free to contact us, we will provide quick response and full support.