A flexible busbar or soft connection is not selected by copper cross-section alone. Current duty, connection faces, heat dissipation, available space and the way the connection moves all affect the correct design. A part can carry the nominal current and still be wrong for the enclosure or installation sequence.
Use this checklist for transformer, switchgear and distribution-panel connections where a rigid bar would create alignment or vibration problems. The final design should be checked against the equipment arrangement and project requirements.
Define the connection duty before choosing the form
State whether the connection carries continuous current, short-duration current, or both. Identify whether it absorbs assembly tolerance, vibration, thermal movement or repeated movement. A static flexible link and a repeatedly flexed link should not be described as the same requirement.
| Input | Details to provide | Design response to confirm |
|---|---|---|
| Electrical duty | Continuous current, short-time duty, system voltage and connection arrangement. | Conductor section, layer or braid arrangement, insulation and stated acceptance basis. |
| Connection faces | Material, hole pattern, hole size, bolt access and mating surface dimensions. | Terminal palms, finish, hardware envelope and interface drawing. |
| Space | Installed length, width, bend radius, nearby barriers and service clearances. | Finished dimensions, bend direction, movement allowance and install sequence. |
| Thermal environment | Ambient conditions, enclosure ventilation, nearby heat sources and duty cycle. | Temperature-rise review under the stated arrangement. |
| Movement | Static tolerance, vibration, thermal movement or repeated flexing. | Flexible form, length, support and expected movement cycle. |
| Inspection | Required dimensions, finish, material records and electrical or mechanical checks. | Sample, first-article and production acceptance plan. |
Check the envelope in three dimensions
Provide the distance between mating faces, the angle between them and the space available around the connection. A two-dimensional length is often insufficient because the link may need to clear an enclosure wall, insulating support, cable termination or moving mechanism.
Send a marked-up photograph or 3D model when possible. Show the installed position, bolt access and the direction in which the link must bend. If the connection is between a transformer and switchgear, include both terminal drawings rather than asking the supplier to infer the arrangement from equipment names.
Do not hide heat in the current number
Temperature rise depends on the complete connection: conductor form, contact surfaces, fasteners, enclosure, airflow and nearby heat sources. Ask the supplier to state the arrangement used for any temperature or current evidence. A value from a different length, terminal, enclosure or mounting condition is not automatically transferable.
For layered copper links, check layer count, separation, edge treatment and the way the layers are terminated. For braided or laminated links, check finished width, thickness, flexibility and bend direction. The product name alone does not freeze these details.
Approve the sample against the installed interfaces
- Verify hole centres, hole diameter, palm orientation and finished length.
- Place the sample in the actual or representative equipment envelope before freezing the drawing.
- Check bolt access, washer clearance, insulation distance and the intended tightening procedure.
- Record the movement or vibration requirement and repeated cycles if relevant.
- Separate appearance and fit approval from electrical, thermal and mechanical acceptance.
Use a custom drawing when the standard part is close but not right
SUNENG supplies flexible busbar connections and can review non-standard length, width, hole pattern, bend angle, insulation and terminal interfaces. Send the equipment drawings, current duty, space envelope, quantity and required documents so the proposed soft connection is designed around the real installation.
Relevant SUNENG products
Send the mating drawings, current duty and available space for a soft-connection review. If the installation moves, describe the movement instead of only sending a current rating.
