CFP-RTD-122 Noise Issues with VFD

Question

Hi,, we are running a Field Point application that has 2 RTD-122 cards (as well as other AI/AO/DI/DO) that monitor various temperatures of our test stand.  Next to the Field Point cabinet we have a 10HP and 40HP VFD that drive each respective water pump.  The temperatures (3-wire 100 ohm platinum) read perfectly fine with the pumps off, but as soon as we start either pump, the RTD signals go crazy.  If fact, they get worse when switch from the 10HP pump to the 40 HP pump.  I have placed a UPS on the 110V feed to the power supply that knocks it down to 24V to feed the Field Point module.  I have also grounded the shield wire in the field point cabinet to earth ground.  Any idea what is going on here and how I can fix it? 

Answer 1

Centerbolt, thanks for the reply, here is some more info:
1.) Yes the drives to have a good ground
2.) RTD wiring is in separate conduit from 480V wiring to the pump, but just to make sure I wired from the RTD-122 card directly to the RTD which I removed from the piping and kept it away from the pump wiring and the problem still continued.
3.) The VFD's have line reactors on them(input to drive, but not on output to motor)
4.) Some sort of magnet?  I will see what I can come up with?
I also have the shielded wire on every channel going to COM as NI suggests, but this had no effect.  Like I said, everything is well with no pumps on, and with the 10HP pump noise is present but minimal(temps change about 5 degrees), but with the 40HP pump on everything goes wacky(temps read 20F to 200F).  I also have analog input channels reading voltages and they are not affected by the running pumps.  I am at a dead end here, any more help is appreciated!