Limit switches in solar tracker systems

The sun moves from east to west over the solar array, reaching its highest point at noon in the south. For the photovoltaic system to generate the optimum yield, the solar panels have to follow the path of the sun, just like sunflower buds. Solar trackers continuously adjust the panels’ horizontal and height angles (azimuth and elevation). In a storm, they turn the panels out of the wind. The tracking control systems use astronomical or sensor-supplied data. Electric motors with gears or electrohydraulic drives move the panel support structures.

What does the snap-action switch do?

Schaltbau S880 snap-action switches function as limit switches and reference switches.

The angles of the horizontal and vertical axes are limited. When the maximum adjustment is reached, a switch is actuated to signal to the tracking controller to stop the drive.

If the angles are adjusted according to the relative position of the drive axes, the solar tracker has to regularly make a reference point run. When the reference switches are actuated, the position is set to a defined value. This ensures that the solar panels are set to the correct angles.

Why use the S880 snap-action switch?

The S880 is the world’s smallest microswitch with positive opening operation and self-cleaning contacts, so it is especially reliable.

The mechanical positive opening operation opens the power circuit even if the contacts are welded, for example after a short-circuit caused by a fault in the system. The self-cleaning contacts reduce the contact resistance and ensure reliable signalling for the entire lifetime of the system.

With the housing measuring just 20 × 9.3 × 6.6 millimetres, the S880 can be optimally integrated into compact solar trackers.