SM Series Busbar Insulator — Willele
Robust busbar insulator series for LV/MV distribution panels, inverters and control cabinets.
BMC/SMC molded body with plated metal inserts for dependable electrical insulation and rigid mechanical support.
Stable under heat, vibration and typical industrial environments; sizes and inserts configurable on request.
Introduction to SM Series Busbar Insulators
Willele’s SM Series busbar insulators keep copper or aluminum busbars firmly positioned while electrically isolating live conductors from enclosures and adjacent phases. The standardized SM geometry provides familiar heights and thread sizes so panel builders can streamline layouts and spares.
Each unit combines a compression-molded BMC/SMC body with a plated metal insert. This structure delivers repeatable tightening torque, clean creepage paths, and dimensional stability through thermal cycling and vibration—ideal for low- to medium-voltage assemblies where reliability matters.
Function and Purpose
Electrical insulation: the molded body acts as a non-conductive barrier to reduce phase-to-phase faults and arcing. Mechanical support: the metal insert and core geometry provide a rigid mounting point so busbars remain aligned during vibration and fault forces.
Willele SM Series Overview
SM-A Series
High-strength options for demanding loads and larger clearances. Recommended where short-circuit forces, stacked bars, or oversized conductors require higher tensile and torque margins.
SM-B Series
General-purpose range that balances compact size with robust performance—ideal for LV switchboards, compact inverters, and control cabinets.
Key Specifications and Technical Parameters
Typical values shown below. Confirm final ratings and tolerances with Willele before design-in.
| MODEL | TENSILE (LBS) | WITHSTAND (kV) | TORQUE (ft-lbs) | SCREW (mm) | SCREW DEPTH (mm) | HEIGHT (mm) |
|---|---|---|---|---|---|---|
| SM-20 | 300 | 5 | 4 | 5 | 7 | 20 |
| SM-25 | 500 | 6 | 6 | 6 | 9 | 25 |
| SM-255 | 400 | 6 | 5 | 6 | 8 | 25.5 |
| SM-30 | 550 | 8 | 8 | 8 | 11 | 30 |
| SM-35 | 600 | 10 | 10 | 8 | 11 | 35 |
| SM-40 | 650 | 12 | 12 | 8 | 11 | 40 |
| SM-45 | 1000 | 14 | 20 | 8 | 11 | 45 |
| SM-51 | 1000 | 15 | 20 | 8 | 14 | 51 |
| SM-60 | 1200 | 20 | 35 | 10 | 15 | 60 |
| SM-76 | 1500 | 25 | 40 | 10 | 20 | 76 |
Dimensions and Size Chart
Electrical and Mechanical Parameters
Electrical
Select a model whose dielectric withstand comfortably exceeds the system operating level and expected transients. Use the drawings to verify creepage and clearance for your installation category.
- Typical operating range: −40 °C to +140 °C (material dependent)
- Insulation stability through thermal cycling and vibration
- Outdoor-grade compounds available on request
Mechanical
Threaded metal inserts enable repeatable torque during assembly and service. The solid core resists compression and provides durable clamping for straight or stacked busbars.
- Verify tensile/torque margin against worst-case short-circuit forces
- Match screw size and thread depth to clamps/base plate
- Optional color coding and height variants for phase ID and layout constraints
Material Composition and Properties
BMC/SMC Body
Compression-molded with fiberglass reinforcement to achieve high dielectric strength and dimensional stability.
Metal Inserts
Brass for corrosion resistance and conductivity; steel for higher thread strength—both with protective plating.
Finish & Options
Standard red color. Custom heights, colors, and material grades available to order.
Applications
- Switchboards, MCCs, capacitor banks
- Solar/ESS inverters and DC bus assemblies
- Industrial drives, rectifier cabinets, control panels
Selection Guide
- Voltage class: choose a model whose kV withstand exceeds operating voltage plus transients.
- Mechanical load: use busbar mass, spacing, and fault levels to select tensile/torque ratings with margin.
- Mounting details: confirm screw size and thread depth; check clamp/washer geometry.
- Environment: specify material grade for temperature, UV, or humidity.
Installation & Handling
- Mount on clean, flat surfaces; remove burrs and debris before assembly.
- Align bars so forces are axial to the insert; avoid prying loads.
- Tighten to the torque listed for the specific model and screw size.
- Re-check torque after the first thermal cycle if required by maintenance policy.
Quality & Certifications
Manufactured under documented procedures with incoming material checks and dimensional inspection. RoHS/REACH statements and third-party reports can be supplied for the exact model you purchase.
Ordering Information
For a fast quotation and drawing release, please provide: model (e.g., SM-35) or target height/thread/depth, insert material (brass/steel) and finish, quantity & destination, and any certification/inspection needs. Optional: color, special compound, packaging.
Conclusion
Willele SM Series combines reliable insulation with rigid mechanical support for modern LV/MV distribution. Share your busbar plan and we’ll recommend the right model and mounting details for your build.
