MicroSolar System

Safety Checklist

Take care the fastener of clamps in your systems

As we all know, any materials within the natural atmosphere will corrode. Therefore, it is important to ensure the engineering operation products have anti-corrosion measure. To reduce the natural corrosion cycle of materials, the chosen engineering materials on fasteners is nothing less than choosing the suitable materials with necessary surface treatments.

Steel is often used as fasteners due to its excellent mechanical properties. Why some non-ferrous metals, such as aluminium alloy can’t be used as key fasteners. First of all, the strength of aluminium alloy is weaker than steel. Secondly, aluminium alloy can be eroded easily within certain natural environment conditions (especially within oceanic climate). The rate of corrosion and destructive effect of the corroded aluminium alloy is terrific. (See figure)

 

 

 

 

 

 

Aluminium surface corrosion

 

Aluminium thread corrosion

 

 

It is critical to be careful when using and designing aluminium alloy as fasteners. Why? The reason for fasteners to fasten two objects together as one effectively is due to the initial tension of fasteners. If the screw threads that provide the initial tension of fasteners are corroded, then fasteners will lose its efficacy.

With a solar mounting system, PV panels are secured by friction forces from the clamps systems.  Therefore, these types of fasteners are considered to be the most important fasteners within a system (According to Australian Standards, only materials with steel characteristics are permitted). When no corrosion protection is applied to aluminium alloy threads and during installation, the anodized thread will be damaged, the initial tension will lost once threads are corroded. As a result, PV panels will slide off from roofs in the future.

Under the extreme condition as shown on figures above, system internal-fasteners did not provide enough friction between components.  This caused the mounting system fails from inside.   

Thus, great safety risks are embedded when using aluminium alloy as fasteners for solar mounting systems. Such system contradicts to the two basic principles mentioned earlier. This is the reason such aluminium alloy fasteners will require special safety certifications.

If any of your roofs are installed with such systems, we strongly recommend having annual maintenance inspections to prevent accidents. (Accident figure)


Copyright ©2011 MicroSolar System Pty Ltd