I have a system that has 2 15 hp pumps with by pass control. DP is set at 25 system runs at 30 to 32 with bypass 100% open. These pumps run 24/7 365 feeding about 30 reheats and a 10" pipe in heat exchanger.(sorry don't know Cap. of exchanger) 1 pump on, 1 on stand by. Supply and return Piping 12 inch, by-pass is 8 inch about 30 feet from pumps. Total pipe run one way is about 200 feet. Pumps on second floor pipes drop down to first floor. EMS system is controlling by-pass valve and right now on and off of pump motors. Using ALC controls.
Thinking of putting vfd on pumps but not sure how to control them. Would I take the bypass out of the control loop or need to add a control point to the system?
I'm more of a tech then control guy so would be installing the VFDs and wiring. Would have my control company come in for programing and start up.
Any help or suggestion would be most helpful.