The ULAMEX PV Profile Connector is an internal splice element manufactured from aluminium alloy EN AW-6063 T6, designed to join two PV mounting rail sections end-to-end while maintaining structural continuity across the junction. The connector slides inside the rail channel, bridging the gap between two profile ends and transferring bending and shear loads across the splice point — enabling installation runs that exceed the length of a single rail extrusion.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | Aluminium EN AW-6063 T6 |
| Available lengths | 100 mm / 120 mm |
| External height | 25 mm |
| Internal height | 22.5 mm |
| External width | 45 mm |
| Compatible profiles | ULAMEX PV profiles 40×40 and 80×40 |
| Fastening | M10 hammer bolts or DIN 933 M10 hex bolts + DIN 6923 flange nuts |
| Thermal expansion gap | 5–10 mm between rail ends |
Installation Guidelines
Insert the profile connector halfway into the open end of the first PV mounting rail, ensuring approximately half of the connector length (50–60 mm) sits inside the first rail. Slide the second rail onto the protruding half of the connector until the two rail ends meet — but do not push the rail ends flush together. Leave a thermal expansion gap of 5–10 mm between the rail ends to accommodate the linear thermal expansion of aluminium over the temperature range experienced on rooftops (-20 to +80 °C).
Secure the connector by installing one M10 hammer bolt (or DIN 933 M10 hex bolt through the side slot) on each side of the splice, positioned approximately 20–30 mm from the rail end. Tighten with a DIN 6923 M10 flange serrated nut to the torque specified by the rail manufacturer (typically 18–22 Nm). The hammer bolt head locks into the T-slot channel, clamping the connector against the inner channel wall.
For long rail runs (exceeding 6 m total), verify that the cumulative thermal expansion does not exceed the tolerance of the end fixings. Each 6 m aluminium rail expands approximately 1.4 mm per 10 °C temperature rise. The 5–10 mm expansion gap at each splice absorbs this movement and prevents buckling forces that could compromise the rail alignment and module clamping integrity.
Applications
- Extended rail runs on large rooftop arrays — splicing multiple rails to cover roof spans exceeding the standard 3.15 m or 6.30 m rail lengths
- Ground-mount solar farms — continuous rail assemblies across multi-row post-mount structures
- Carport PV canopy systems — long-span overhead rail assemblies requiring multiple rail sections
- Commercial flat-roof installations — east-west dual-pitch systems with extended rail lines
- On-site length adjustment — extending rails where site measurements differ from the design layout
Material Properties
EN AW-6063 T6 aluminium — the same alloy used for the ULAMEX PV mounting rails themselves — ensures identical thermal expansion coefficients between connector and rail. This material matching eliminates differential expansion stresses at the splice joint that could cause binding or loosening over thermal cycles. The T6 temper condition provides yield strength of approximately 170 MPa, sufficient to transfer the bending moments across the splice without permanent deformation.
The connector dimensions are precision-extruded to provide a close sliding fit inside the rail channel: tight enough to prevent lateral play, but loose enough to allow insertion without excessive force. The 25 mm external height and 45 mm external width are matched to the internal channel geometry of the ULAMEX 40×40 and 80×40 profile series.
Compatibility
The ULAMEX profile connector is designed for:
- ULAMEX PV profiles 40×40 mm — standard single-module-width rail
- ULAMEX PV profiles 80×40 mm — double-width rail for heavy-duty and dual-row applications
- M10 hammer bolts — primary fastening method through the T-slot channel
- DIN 933 M10 hex bolts + DIN 6923 flange nuts — alternative fastening through the side slot
- All ULAMEX rail-mounted components — clamps, brackets, and accessories mount normally over the spliced zone
Why ULAMEX
ULAMEX is an EN 1090 certified B2B wholesaler supplying the complete PV rail system — profiles, connectors, clamps, roof hooks, and all fastening hardware. Profile connectors are stocked in both 100 mm and 120 mm lengths for immediate dispatch in bulk packaging. One supplier, one delivery, one invoice for the entire mounting system.
Frequently Asked Questions
Q: Why must I leave a thermal expansion gap?
Aluminium expands approximately 0.024 mm per metre per °C. A 6 m rail on a rooftop experiencing a 60 °C temperature swing (from -20 °C winter night to +40 °C summer midday) expands by approximately 8.6 mm. Without a gap, the expanding rails push against each other, generating buckling forces that can misalign modules and compromise clamping. The 5–10 mm gap absorbs this movement.
Q: 100 mm or 120 mm connector — which should I choose?
The 120 mm connector provides a longer overlap on each side of the splice (60 mm per rail versus 50 mm), offering higher shear and bending load transfer. Use 120 mm for spans with high wind loads, snow loads, or where the splice point is located far from the nearest roof hook support. 100 mm is adequate for standard residential installations with roof hook spacing under 1.5 m.
Q: Can I mount a module clamp directly over the splice point?
Yes. The profile connector sits inside the rail and does not obstruct the T-slot channel. Hammer bolts and clamps can be positioned at any point along the rail, including directly over the splice. However, ensure the splice is secured with its own dedicated bolts — do not rely on the clamp bolt to also secure the connector.
Q: Is the connector load-bearing?
Yes. The connector transfers bending moments and shear forces across the rail splice, maintaining structural continuity. However, the spliced joint is not as strong as a continuous rail. For spans with high structural demands, position the splice point close to a support (roof hook or post) rather than at mid-span where bending moments are highest.
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