I am currently installing 3000 individual solar panels on top of a roof that is about 4 acres in size(see inclosed pics) My question or as it is my concern is with such long runs of imc what would be the propper distance for my expansion couplings.As it is now I have put them at 150 feet apart and spaced the supports at 8 feet apart
iwire may have something there because if you look at 300.7(B) FPN it says to multiply the values in Table 352.44 by a factor of .20.If I did the math right that is only .8 inches of movement with 100 degree temperture change per 100 feet so if you installed it at 50 degrees it would only be .4 inches of movement at zero degrees(F) and 100 degrees (F) so that is not very much at all.It equates to .008 inches of movement per foot.I believe you are more than covered.
Leave your supports a bit loose or use one trade size over on supports to allow for any movement.Going a step further with your design of an expansion fitting every 150 feet with an anchor in the middle you have 75 feet to expand over, 75 x .008 is .6 inches of movement,check my figures,smile
