Anyone out there using a Hamilton MPE2? I have one integrated onto my STAR systems, it works about half the time… the issue is always “PID control of the valve was lost due to too large of an error between the desired and actual output pressures.”
I am running a filtration step process that takes nearly 2 hours to complete.
ControlPoint = pressure,15,300" looped 3 times ---- top wells off ---- loop x times.
I clean my system daily with EtOH and DI water after.
I’ve used one in the past, but don’t have access to one at the moment to test. I remember it being a bit finnicky to initialize correctly at the start of a method, but didn’t have issues once it got going. Our filtration steps were more like 3 minutes, so a far cry from 2 hours.
It sounds to me like the PID controller output is maxing out (aka the valve is fully open) and the pressure feedback is still too far from the setpoint. What is your air source? There’s a chance that the MPE2 is using more air than the source can generate, and therefore the pressure is slowing dropping out of range over the 2 hours.
Could also be more of a software issue, something like integral windup in the PID controller. Have you tried, say, two 1 hour filtration steps instead of one 2 hour step?
Thank you for this post! We have air line from the wall into regulator (100psi) then to MPE2 control box which connects to the MPE. I have broken my cycles in 5 min intervals in hope to not reduce work load on the device. Still getting back the PID issue, after 20 - 120 seconds into the cycle.
I have sent it in to Hamiltons MPE2 team, so if I have any further development I will be sure to enlighten all using this product.
Can you share the full text of the error? It should say whether it’s associated with the high pressure valve, low pressure valve or manifold. A valve error can be a sign of a leak. One thing to test would be holding at 10 psi which goes through the low pressure circuit and holding at 20 psi and seeing if either of those error.