This guide provides the standard installation procedures for the Ziyuan Energy L-Foot Mounting System on metal roofs. For a broader comparison of roof hooks, L-feet, hanger bolts, and other roof attachments, see our pitched roof solar mounting brackets guide.
Disclaimer: This guide is for product installation reference. Final design, load verification, electrical bonding, and code compliance must be confirmed by a qualified professional under applicable local regulations. Torque values, fastener selection, and span spacing must follow your project-specific engineering drawings.
Installation Video
Watch our quick assembly demonstration to understand the basic clamping and rail-mounting workflow.
Note: The video serves as a visual assembly guide. For complete structural and electrical steps, follow the written procedures below.
Video Transcript Summary
- 0:00–0:06: Positioning and fixing L Feet
- 0:07–0:15: Installing the aluminum rail
- 0:16–0:18: Securing the PV module with end clamps
- 0:19–0:25: Installing mid clamps between modules
L-Foot System Components
Ensure you have all necessary components before beginning installation:
- L Feet
- Rail
- Rail Connector
- End Clamp
- Mid Clamp (with Earthing Plate)
- Grounding Lug
Technical Specifications
| Parameter | Specification |
|---|---|
| Main Material | Aluminum Alloy AL6005-T5 |
| Surface Treatment | Anodized |
| Fastener Material | Stainless Steel |
| Intended Application | Metal-roof PV mounting applications; final suitability is subject to project-specific engineering review |
| Design Standards | Design reference standards may vary by project and market |
Tools Required
- String line and tape measure
- Power driver or electric driver with the appropriate hex sockets for M8/M10 fasteners
- 9 mm drill bit
- Marking pen
- M8 torque wrench and 6 mm hex key
- Adjustable wrench and rubber mallet
Before You Start
- Confirm approved project drawings and structural designs.
- Locate purlins or the main supporting structure beneath the metal sheet.
- Check roof condition and local weather.
- Follow local safety and electrical requirements.
Step 1: Mark Purlin Locations and L-Foot Positions
Mark the suitable positions for the L Feet. Do not rely on roof sheeting alone unless a project-specific engineering design expressly permits it. The mounting points must follow the approved structural design and engage the supporting wood or steel purlins under the roof sheet.
Step 2: Fix L Feet to the Supporting Purlins
Install the L Feet on the metal roof using the specified self-tapping fasteners. Confirm that all L Feet are level and aligned across the array. Tighten the fasteners in accordance with the approved project documentation and applicable torque requirements.
For roof-profile requirements, mounting options, and planning considerations, see our trapezoidal metal roof solar mounting guide .
Step 3: Install and Splice Rails
Splicing (if necessary): Position the Rail Connector centrally between the two rail sections and install it in accordance with the applicable product drawing. Secure the connection with the designated M8×10 bolts.
Mounting: Install the rail onto the L Feet using the M8×25 bolt set. Tighten all fasteners according to the approved project torque specifications.
Step 4: Secure PV Modules with End and Mid Clamps
Place the PV modules on the installed rails. Use End Clamps at the outer ends of each module row and Mid Clamps, including Earthing Plates where supplied, between adjacent modules. Tighten the clamps according to the approved torque specifications.
Where supplied, the Earthing Plate is intended to establish electrical bonding between the PV module frame and rail. It does not replace the project-specific grounding and bonding design.
Step 5: Install Grounding Lugs and Complete Electrical Bonding
Install a Grounding Lug at the end of each rail, as specified in the installation manual. Complete all grounding and bonding connections in accordance with the approved electrical design, the applicable local code, and the requirements of the PV module and inverter manufacturers.
Step 6: Final Inspection Checklist
Before leaving the site, perform the following checks:
- Are the L Feet positioned and secured into the load-bearing purlins/structure according to the design?
- Are rail splices, L-foot connections, and clamps tightened to the approved torque requirements?
- Do the End and Mid Clamps match the PV module frame height?
- Are earthing connections and grounding lugs completed per the approved electrical design?
- Have all small parts left on the site (such as bolts, conductive sheets, etc.) been retrieved to prevent loss or roof damage?
How to Prevent Stainless-Steel Thread Galling
Due to its ductility, stainless steel behaves differently than carbon steel. Improper handling during installation can cause bolts and nuts to lock up (thread galling). Prevent this by following these practices:
- Reduce Friction: Ensure threads are clean and free of dirt or debris before assembly. Use only a compatible anti-seize lubricant where permitted by the fastener and mounting-system instructions. Confirm the specified tightening torque after lubricant use.
- Correct Operation: When screwing, it must be perpendicular to the axis of the thread. Do not tilt.
- Control Speed: Use a torque wrench or socket wrench whenever possible. Avoid high-temperature use and rapid temperature rise by not using fast rotation. If using a power driver, reduce the speed significantly.
Frequently Asked Questions
Need Project-Specific Engineering Support?
For product technical documentation, OEM requirements, or project-specific mounting information, contact the Ziyuan Energy team. For verified load capacities, fastening specifications, and final system design, please request the applicable engineering documentation for your project.
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