ommon mode SPD between phase and PE or phase and PEN is installed whatever type of system earthing arrangement (see Fig. 1).
The neutral earthing resistor R1 used for the pylons has a lower resistance than the earthing resistor R2 used for the installation.
The lightning current will flow through circuit ABCD to earth via the easiest path. It will pass through varistors V1 and V2 in series, causing a differential voltage equal to twice the Up voltage of the SPD (Up1 + Up2) to appear at the terminals of A and C at the entrance to the installation in extreme cases.
To protect the loads between Ph and N effectively, the differential mode voltage (between A and C) must be reduced.
Another SPD architecture is therefore used (see Fig.2)
The lightning current flows through circuit ABH which has a lower impedance than circuit ABCD, as the impedance of the component used between B and H is null (gas filled spark gap). In this case, the differential voltage is equal to the residual voltage of the SPD (Up2).
Overvoltage may occur in electrical installations for various reasons. It may be caused by: 1. The distribution network as a result of lightning or any work carried out. 2. Lightning strikes (nearby or on buildings and PV installations, or on lightning conductors). 3. Variations in the electrical field due to lightning. Like all outdoor structures, […]
Ylong offers the most comprehensive portfolio of Type 1 and Type 2 surge protective devices that can be externally or internally mounted. They help reduce costly downtime while protecting sensitive electronic equipment against damaging effects of transients caused by lightning, utility load switching, internal load switching, and more.
Surge protective devices are crucial components of any electrical installation. They play a vital role in protecting your devices and equipment from voltage spikes and surges. But what are they exactly? In this blog post, we’ll take a closer look at surge protective devices and why they are essential for your home or business. […]
We focus on providing high-quality equipment and components to meet the needs of customers around the world.
