Observing power factor on PQM at one of the sewage pumping station we noticed that power factor become negative (≈-0.85) when one of the pumps is running.
Assuming that some capacitive load in the VFD motor circuitry exist, we can accept this situation.
When there is no pump running pf is 0.98...
Hi,
I am looking for the option to replace 'classic' float switches used in sanitary pumping applications, with something more reliable with less maintenance.
Maybe some type of capacitive proximity switches?
We need four switches for LoLo, Lo, Hi, and HiHi alarm, connected to the PLC digital...
Hi,
I am currently working at one pumping station with 3 VFD pumps (asynchronous motor, 208V, 42kw.
The strange thing is when panel is powered with no pump running VFD draws about 50A per phase.
Rest of the load is disconnected. How this is possible?
Could someone explain this situation.
RSTENG
Hi,
I am currently reviewing one application for CPU 1769-L32E created with RSLogix5000 ver17.
I came accross very strange way of programming using outputs in series. In one example I foung three output contacts OTE, OTL and OTU in the same rung.
Please explain what exact problem could be a...
