What does it mean for an apparatus to be labeled as rainproof?

An apparatus labeled as rainproof indicates that it is specifically constructed to prevent rain from interfering with its operation under defined test conditions. This means that the design includes measures to block water ingress and ensure that the device functions correctly when exposed to rain. The term "rainproof" typically refers to a certain IP (Ingress Protection) rating, which specifies the level of protection against moisture, and this rating is determined through testing under standardized conditions.

Understanding this term is crucial for selecting electrical equipment that will perform reliably in outdoor or wet environments where rain can be a factor. While it is important for equipment to be resilient in various weather conditions, the designation of rainproof specifically pertains to its ability to function without operational issues when wet, rather than its resistance to extreme weather or flooding.