Mid and finish clamps are two of probably the most vital elements that safe PV modules to the racking system. Right here to elucidate what they do, how they do it and what to search for in a clamp are Mark Gies, director of photo voltaic enterprise at S-5!, and Johan Alfsen, senior director of Coaching at K2 Systems.
Mid and finish clamps defined | “Many photo voltaic mounting and attachment programs make the most of overhead clamps to connect photo voltaic modules and most certainly have two interchangeable clamps: mid-clamps and end-clamps,” Gies says. “The mid clamps clamp over the perimeters of the modules positioned within the inside of an array (every mid clamp is shared between two adjoining modules), and the tip clamps connect excessive of the module sides on the perimeter of an array.
“The mid-clamp has two distinct symmetrical clamping surfaces for the aim of attaching adjoining module sides. Finish clamps, alternatively, solely require one clamping floor.”
Concerns | “Since an finish clamp solely attaches to at least one module, it’s topic to rotational forces attempting to slide the clamp off the highest of the body. So, an finish clamp must be inflexible sufficient to by no means rotate and to not slip off a module body,” Gies says.
“When contemplating overhead clamps, it is vital that the clamping floor complies with the set up necessities of the photo voltaic modules and that they’re sturdy sufficient to withstand the forces calculated from the location situations. Moreover, it’s vital that the tip clamps are designed to resist bending and rotation; these clamps mustn’t ever slip off the module frames.”
Many module clamps are additionally UL 2703 listed to offer module-to-module and module-to-rail bonding, eliminating the necessity for jumpers and copper wires.
Set up | “Sometimes, these elements include chrome steel and aluminum,” Alfsen says. “It’s quite common for installers to make use of affect drills to safe mid and finish clamps. Utilizing an affect with too excessive of a setting can truly trigger cross threading and injury the clamps. All clamps have a torque setting to be correctly tightened to producer’s specs.
“Realistically, most installers will not use a torque wrench on all clamps to test for correct torque settings. Our recommendation is to make use of a torque wrench on a pair clamps to calibrate your drill to the best setting in order that you don’t over or beneath torque the clamps.”