Busbar Conjunction (Joint) Box Series
Insulated boxes and covers for busbar joints and taps. Busbar joint boxes enclose and insulate the tap or joint so crews and adjacent metal are protected. We build them in insulating sheet to the busbar layout. Boxes are supplied with the covers and fixings for the joint arrangement you specify. Yes. Send the busbar layout and we build the box, cover and fixings to fit. Recovers to a tight fit on
Insulated boxes and covers for busbar joints and taps. Busbar joint boxes enclose and insulate the tap or joint so crews and adjacent metal are protected. We build them in insulating sheet to the busbar layout. Boxes are supplied with the covers and fixings for the joint arrangement you specify. Yes. Send the busbar layout and we build the box, cover and fixings to fit. Recovers to a tight fit on
Technical specifications
| Material | Insulating laminate |
| Use | Busbar joint / tap enclosure |
| Supply | Box + cover + fixings |
| Standard | ASTM or IEC standards referenced in your drawing; COA supplied per batch. |
| Operating temperature | Per drawing specification |
| Dielectric strength | ≥ 20 kV/mm (per ASTM test method) |
💾 Datasheets & Test Reports
Download the technical data sheet for this product (PDF).
Information required for quotation
| Base tube | Approved material grade, ID, OD, wall and conditioning as per drawing |
| Datums | Drawing datum scheme and measurement reference |
| Key dimensions | Feature positions, depths, pitch and diameters reviewed before quotation |
| Thread / profile | Standard or custom profile, class, depth, engagement and gage method |
| Other features | Holes, slots, steps, chamfers, cuts and marking |
| Acceptance | Tolerances, sampling, gages, FAI and inspection report |
| Order | Prototype and production quantity, packaging and delivery target |
Applications by industry
- Distribution conjunction (junction) boxes for load-taking busbars
- Motor control center busbar transition boxes
- Transformer secondary bus riser junction boxes
- Splitter/feeder junction boxes in panel rooms
- Busbar tap and joint isolation boxes
- Prefabricated busway coupling boxes
Why insulating laminate + shrink assembly for this application
The junction box confines the joint, creepage and phase separation of take-off busbars into a compact insulated envelope, so live metal stays inside a cTc-compliant barrier.
Confirm ingress rating and phase separation against the box class; vents and cable entries must be designed for the take-off exits, not left to field drilling.
Standards: IEC 60439 / IEC 61439 (LV switchgear assemblies), UL 508A (USA).
Feature and remaining-wall review
CNC turning, grinding, drilling and milling to your drawing. Tolerances and gaging methods agreed before quotation. Review feature depth, edge distance and remaining wall against critical geometries. Capability is confirmed on your drawing, not from a blanket tolerance.
Inspection and traceability
We state the control plan with you. Batch traceability links raw material lot to finished part.
- First-article inspection (FAI) per your plan
- In-process dimensional checks at every station
- Batch certificate of conformance (COA) supplied on request
- Lot traceability to incoming material certificate
- Dielectric strength and insulation resistance testing available on request
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Common questions
Can you hold tight tolerances?
Tolerances are confirmed against your drawing, not published as a blanket claim. Send the print and we review manufacturability.
What lead time should I expect?
Prototypes: 7–10 days after drawing approval. Production quantities: 30–45 days. Both assume raw-material availability and confirmed PO.
Do you provide certificates?
Yes. Material COA, first-article inspection (FAI) and batch traceability supplied per your plan on request.
What is the MOQ?
Prototype quantities of 1–10 pieces accepted. Production MOQ starts at 100 pieces for standard grades, 500 for specialized forms.
Do you build the box to the joint?
Prototype quantities of 1–10 pieces accepted. Production MOQ starts at 100 pieces for standard grades, 500 for specialized forms.
Engineering Guides & Selection Notes
Related technical articles that help specify this product.
Get pricing for Busbar Conjunction (Joint) Box Series
Attach the drawing with annual volume. We check the material against your duty and tolerance, verify ID / OD / wall / features, and respond with manufacturability notes and pricing.