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	Subject - Elevator feeder conductor sizing bobwired2 I have been assigned a project that involves 20 elevator upgrades. Our scope of work involves repiping and pulling new copper conductors to the new transformer supplied by the Elev. contractor. Niether the Owner or the Elev contractor is providing 480v 3phase primary wire size to these transformers. Anybody remember a formula that shows how to size these conductors for this type of installation. Thanks lctrc789 You are not saying whether they are delta or wye connected. What is the secondary voltage for these installations. What is the secondary amperage of these motors as well. then you can use the formula. KVA X 1000 Primary (divided) by 480 (divided) by (1.732) = then X 125% for the maximum Overcurrent Primary conductor and amperage size, (Primary) Then refer too 310-16 for wirse size. Guys I am rusty here but check me out for sure. Ryan_J Conductors are sized to the load served. See 215.2 and 210.19. Also, be mindful of the selective coordination requirement found in the elevator article (645???). This will mean that circuit breakers are not an option. Alfred Ryan In article 620.13 there is a line diagram (example ) step by step of how to calculate this. Just follow the diagram, apply each step and do the calculations. Thanks Alfred Johnson