Wet Well Volume 1

[BlazerV60]

Hello Env. Engs,

I'm designing a wet well for a certain city in southern California. Through looking at the Hydraulic Institute manual, I found equations which would help me size the wet well if I had constant pumps. The equations for constant pumps have pump cycle start and stop times. However, I'm using a VFD pump which doesn't have pump cycle start and stop times. Thus far, I haven't found any equations to size a wet well that uses VFD pumps.

I managed to determine that my wet well diameter is 4' and that the max flow coming into my wet well is 1400 GPM. The sewer main that pumps the sewage into the wet well has a 2' diameter. The pump I selected is a submersible one, I will be using two pumps (one is a backup). The only thing I need to figure out is the height of the wet well. Can anyone suggest me a wet well height that sounds reasonable for my situation?

Thanks!

 

[QualityTime]

The following was explained to me a long time ago about the difference between a constant speed motor and a VFD motor:

VFD motors, as I understand it, are just "regular" motors with larger external casings. The larger external casings allow the heat to be dissappated faster. So for a 20 hp VFD motor you would probably be getting a 25 hp casing