VFD vs Liquid Rheostat Controls
VFD vs Liquid Rheostat Controls
(OP)
For a variable speed pumping application, what are the main advantages of variable frequency drive (VFD) over liquid rheostat controls? Are there any advantages of liquid rheostats over VFDs?
Any help would be much appreciated. Thanks.
Any help would be much appreciated. Thanks.





RE: VFD vs Liquid Rheostat Controls
RE: VFD vs Liquid Rheostat Controls
other technology -- is that it can't fail instantaneously
so with regular maintenance it is very reliable.
On the other hand it constantly looses water, so maintenance
is a must.
<nbucska@pcperipherals.com>
RE: VFD vs Liquid Rheostat Controls
The VFD will be much more efficient and provide better speed/level control. It should be more reliable as well.
The existing wound rotor motor can be used with a VFD by shorting out the rotor windings. But you might be better off with a new squirrel-cage motor since the efficiency would probably be better and you can get an inverter-duty motor that will hold up better.
Not many new liquid rheostat systems being installed these days.