Sawdustguy, that is what I was wondering as well.
Like you said, I was hoping the relays would be fine for the pumps since they don't cycle as much as the elements and are low power.
Worse case, the box is perfect , with a nice fan and vents already installed with a DIN rail.
Hoping that some of the electronics / electrical experts may know more about the usefulness of the variable speed drive.
I could always buy a 240 V March pump if it would work with the speed controller. I understand that Asyncronous motors are induction motors, which I thought the march type pump motor would be induction ?
Any thoughts ?