Are you using electrical equipment outside your home? If the answer is yes, then the chances are, you need to fit weatherproof electrical sockets to the exterior of your building.
You may think that it is adequate to run a power cable through the window outside quickly. You might also believe that this will be entirely safe, however, have you considered when rains heavily, the water could run back down the cable to the socket inside and potentially cause a short circuit or the risk of electrocution?
Also, your internal power circuit may not have any form of Residual Current Detection (RCD) protection fitted to it. Although all new modern houses and flats do require the fitment of RCD’s, not all older homes and factories have this electrical protection installed on their circuits.
In general, all external power circuits typically have RCD’s fitted to them. It is because most often, external equipment used from the sockets are items like hedge trimmers and lawnmowers where there is a high risk of cutting through the electrical cable used to power them and with an RCD fitted. If this happens, it cuts the power out in milliseconds before the user is even aware that cable has been cut through and safely prevents any risk of electrocution.
The key reason to use weatherproof sockets is that they are specifically designed to be weatherproof and water resistant and are IP rated and will offer various levels of IP rating such as IP44, 55 & 66. Dependant on the IP rating it will depend upon whether the socket is designed just to be weatherproof when not in use, or to be able to be used while it is raining, as an example, and remain waterproof and electrically safe.
Obviously, the weatherproof electrical sockets increase in price as the IP rating increases. However the higher the IP rating, the more electrically safe they are.
It is however obviously a good idea to go for the highest IP rated socket that you can afford to provide maximum electrical safety to you, or your workers, as the cost of any fatal accident can far outweigh the cost of the few pounds saved on the purchase of a cheaper socket.