As it is known, loads can be categorized as active and reactive. Reactive loads can further be divided into inductive and capacitive loads. It is important to pay attention to inductive loads in a Smart Home system. These loads include devices with electric motors (such as fans or pumps) and devices with transformer power supplies (such as power stabilizers). Motorized curtains, blinds, and shades also belong to inductive loads.
One of the disadvantages of inductive loads is the creation of obstacles and disturbances during their switching off due to high-voltage voltage spikes that occur at that moment. During these spikes, the voltage values can reach 2-3 times higher than the supply voltage and cause arcing between the contacts of the output relays of control devices (controllers) when switching off the loads.

The controllers by i3 Engineering implement protection against the occurrence of arcing between the contacts of the output relays by installing appropriate varistors (or suppressors) in parallel to the contacts of these relays. They limit the maximum voltage on the relay contacts and accordingly reduce the level of switching disturbances and increase the relay's service life.
Another feature is the increased starting current of motor consumption by 2-5 times when they are switched on. Therefore, this current should not exceed the nominal current of the contact group of the relay.

Special attention should be paid to the switching of reversible motors used in curtains and blinds, where they operate in forward and reverse modes. They have 2 windings wound on a single core, which are switched according to the direction of movement. At the same time, a voltage is induced in the other winding, which is added to the contacts of the relay that switches it, which can damage the protective elements of the device.