so i have 4 25gpm wells feeding a 1000gal tank (T-1), with an additional 15gpm from a decant tank for 3hrs every 12hrs.
P1 and P2 both controlled by powerflex 525
P1 flow min is 50gpm (30hz), max 125gpm (51hz)
P2 flow min is 65gpm (30hz), max 140gpm (54hz)
PID loop is being driven by the PLC (control logix l33er)
T-1 level is the control setpoint, with is 2.5 with an overall tank height of 5. previously we had 2 of the wells flowing to T-1 and i was able to get the loop dialed in with PI and P-1 would vary a few gpm.
P-2 i could never get under control, now with 4 wells going and the decant flow, P-1 flow it is all over the place, which cascades to T-2.
process 1 doesnt care much about fluctuation in flow. the sand filter DP is really sensitive to flow and process 2 is sensitive to flow as well.
the OEM i work for provided process 1. we won the contract for operations, which was supposed to be turnkey at the time of handoff, but was not even close as it typically is. i now have access to the PLC, so i can start trending things. dont have much lead way in what i can do from a logic standpoint because politics.
so after messing with PI setting, i am not getting the results i need.
after lots of reading, D still doesnt 100% make sense in my head so im hesitant to go that direction.
i found a thread where a guy was having issues and ended up cutting down the accel/decel time from 10s to 1s and it helped get his issue sorted out.
so my questions
- am i expecting to much control from the pump with the retention time in the tank being so low?
- if the accel/decel time is 10s from 0 to 60hz, does that apply only on start up or does that linear relationship apply to all adjustments in speed?
- it doesnt appear that a lot of people use D, when would you apply that?
P1 and P2 both controlled by powerflex 525
P1 flow min is 50gpm (30hz), max 125gpm (51hz)
P2 flow min is 65gpm (30hz), max 140gpm (54hz)
PID loop is being driven by the PLC (control logix l33er)
T-1 level is the control setpoint, with is 2.5 with an overall tank height of 5. previously we had 2 of the wells flowing to T-1 and i was able to get the loop dialed in with PI and P-1 would vary a few gpm.
P-2 i could never get under control, now with 4 wells going and the decant flow, P-1 flow it is all over the place, which cascades to T-2.
process 1 doesnt care much about fluctuation in flow. the sand filter DP is really sensitive to flow and process 2 is sensitive to flow as well.
the OEM i work for provided process 1. we won the contract for operations, which was supposed to be turnkey at the time of handoff, but was not even close as it typically is. i now have access to the PLC, so i can start trending things. dont have much lead way in what i can do from a logic standpoint because politics.
so after messing with PI setting, i am not getting the results i need.
after lots of reading, D still doesnt 100% make sense in my head so im hesitant to go that direction.
i found a thread where a guy was having issues and ended up cutting down the accel/decel time from 10s to 1s and it helped get his issue sorted out.
so my questions
- am i expecting to much control from the pump with the retention time in the tank being so low?
- if the accel/decel time is 10s from 0 to 60hz, does that apply only on start up or does that linear relationship apply to all adjustments in speed?
- it doesnt appear that a lot of people use D, when would you apply that?