This came up at a meeting of inspectors and contractors: If a environment is expected to have a change in temperature of 110° F. over the seasons and we are installing expansion fittings to compensate for this per 353.44 (2008 NEC), how do we set the fittings if we are installing conduit that has been in a warm storage area and we take it into a colder area and start installing it? For example— Warm truck or warehouse is 60° F ambient and the conduit is taken outside to a 10° ambient. Should there be a waiting time for the conduit to get tempered to the colder area? If so how long is this time? Sounds like an obvious simple answer but I don't know how to answer it. Temperature over the seasons will range from -10° F to 100° F .


George Little