The control scheme could employ。。。如何翻译? The control scheme could employ two VFD’s for variable speed control of each pump and a PLC to supervise their operation. Another option would be to use a single drive that would engage an across the line starter and bring a constant speed pump on line when flow exceeds 400 gpm. We will discuss these control options in detail in a future column 查看更多2个回答 . 4人已关注