I have recently installed a 2 HP 3 phase motor on my lathe along with a 2 HP TECO VFD from automation direct. The lathe slows down under all but the lightest cuts. for example at 46 hz took a light facing cut lathe slowed to a crawl. Is this a normal result of not running it a 60 HZ? It does the same thing at 60hz just not as bad.