NR4 and RTD Sensor Problems


Thread Starter


We are an OEM that manufactures cooking and chilling equipment for the meat Industry. Recently we have run into problems with our RTD sensors failing and or taking out the NR4 Modules and at times even taking out the Power Supply for the PLC Rack. At this point it is difficult to pinpoint the actual culprit wether it is electrical noise, the quality of the sensors, or the actual NR4 cards themselves. Any Ideas.
I've also had a few of these modules fail connected to 199 ohm RTDs monitoring motor winding temperatures on centrifugal blowers. I think its probably due to the large amounts of noise present at the RTDs but the filures are rare and I haven't isolated the cause. Always make sure the chassis and cables are properly grounded.