The Vaisala WSP152 Surge Protector is a compact transient overvoltage suppressor designed for the protection of the USB connection of a PC connected to the Vaisala WXT520 or WMT52. The WSP152 is designed to protect the host PC against surges entering through the USB port. For example, a nearby lightning strike may induce a high-voltage surge, which is not tolerated by the protection of the USB cable or the port itself. Therefore, additional protection is needed, especially where frequent and severe thunderstorms are common and where long cables of more than 30m are used. Please note that the USB connection of a PC is for indoor use only.
The Vaisala WSP152 Surge Protector offers three-stage protection against surge currents up to 10 kA that may enter through the USB cable or the port. The WSP152 has four channels, two of which are dedicated to power lines and two for data lines. Each channel uses a three-stage protection scheme as follows: first there are discharge tubes, then voltage dependent resistors (VDR), and finally transient zener diodes. Between each stage, there are either series inductors or resistors. Both differential and common mode protection is provided for each channel: across the wire pairs, against the operating voltage ground, and against earth. The WSP152 also includes noise filtering against HF and RF interference.
Vaisala recommends using the WSP152 when USB cables are used for permanent connections. The surge protector is always recommended when there is an elevated risk of lightning strike.