when i purchased a fan motor from an ac supply house i was informed that i would need to change the cap from a 5 to 7.5. I had just installed a new 45mfd cap which was already in the unit. do I need to install a second one? and if so how do i wire it in? The motor I took out was a single phase 1/3 hp 1075 rpm 208-230 volt. the new motor has all the same numbers except the fact that it requires 7.5 cap.