Turbotalon22 (Customer) asked a question.
I am using the click C0-04RTD card and some prosense pt100 sensors the run of cable is about 8 feet loacated in near proximity to the 480v supply wires for the VFD. The problem is once i start the drive my temp reads jump around by as much as 40 degrees. Anyone got any ideas to mitigate this?
Todd,
Thanks for your response. To answer you.
1. I am only using 3 wires from rtd to card. So i should gnd the 4th wire then? Also the unlabled ports on rtd card are not tied to common. Just have the unused channels jumped together.
2. I am not using sheilded cable from drive to the vfd.
3. My m12 rtd cables are also not sheilded.
At minimum, shunt input 4 and use shielded cable to the motor. I use THIS CABLE as most of my motor applications are 1HP or less at 208-230/480V (the full load amperage; aka FLA draw of the motor will determine what gauge wire to use). Connect the shield at the drive end ONLY. VFDs do create a lot of noise. Back in 2012, I used a GS1 drive that "talked to" a AD photoeye and our "quick fix" was to change the routing of the photoeye cable. I would not recommend that now. If those two things don't solve the erratic temp readings then shielded cables for the RTDs will be necessary.
If you have any other questions, post them here. Good luck!
Todd, ive read one can just use a 4-20 mA sensor and not have this issue. What is your experience?
I have 4-20 transmitters i can hook this prosense rtd up too. And just utilize the extra 2 channels on my 0-20ma card. Do you think this could work?
My experience is unused RTD channel's not shunted leads to erratic behavior. The slip sheet from the C0-04RTD has this image and I've circled the note "Connect unused channels."
Todd,
I had both unused channels shunted as shown. It did not help the issue.due to the complexity of running new sheilded vfd to motor wire and new sheilded m12 cords for the rtd, i tried a 4 to 20 rtd transmitter and fed my expansion card with the input and has solved the issue. The temp is stable now with motor running.
Todd,
I had both unused channels shunted as shown. It did not help the issue.due to the complexity of running new sheilded vfd to motor wire and new sheilded m12 cords for the rtd, i tried a 4 to 20 rtd transmitter and fed my expansion card with the input and has solved the issue. The temp is stable now with motor running.