As it says above really. I have a couple of Europa steel enclosures that have switches in them for controlling outdoor lights.
I opened one of these up yesterday, and noticed an amount of condensation on the inside walls of the cabinet. The cabinets are sealed except where the mounting bolts go through the back. I may unbolt it and fit rubber washers to see if it helps, Is this a common occurence, and if so is there any sensible way of controlling this ?
I did some research on this a long time ago but never implemented it so can only give you pointers. You need to install a small heater inside the enclosure to keep the temperature just above the dew point. Search on Google for a small heater, similar to a fish tank heater, that you can install inside the enclosure. There is a name for it but I can't remember what it is. Also, don't seal the unit completely. Add a small hole at the bottom of the enclosure.