2hr Cable
2hr Cable
After doing some research it turns out the cable is fire rated (1hr, 2hr, 3hr) etc. if is a special fire rated cable complying with the applicable UL standards this includes MI cable, RHW-fire rated cable, and a special MC fire rated cable, however to achieve the 2hr fire rating for the special RHW it has to be installed in conduit and per the manufacturers UL system number the way it was tested. it turns out that 2" concrete encasement is acceptable but the funny thing is that when UL does the test it tests the concrete not the cables the test is carried out without conductors installed in the pipe. interesting. but it turns out you have to use a cable listed to UL standard for the rating you are achieving and install it to the manufacturers UL System number, unless installed in a "fire rated enclosure" built to the UL standard.