We've just put in a bread cooling conveyor system. It has two sections, 8ft, and 25ft. Each belt has its own motor, both being 3PH, 230v. Each motor draws approximately 2 Amps. We put in a 5 HP Lenze Inverter Drive to control both motors because, before installing the Drive, both belts were running at the same speed, and a bit too fast for us. Now, with the Drive, the 25ft belt is noticeably slower than the 8 footer. Help?