dPAD (Customer) asked a question.
One of my clients is using a TA2613 and a TA2633 temperature transmitter from IFM for one of their applications( DATA Sheets attached) . The Analog input card we are using is a P1-08ADL-1. They have gone through about 5 of these cards already. It works fine to begin with they get readings they expect and after some amount of time the temperature continues to rise while it should be ambient, eventually they disconnect the sensors and it still reads an astronomical number like 140 C and stays that way until they replace the card and the cycle continues. We simulated the 4-20 signal at our panel shop with a process meter and everything obviously tested out normal. They have it wired up like shown in the pictures. Wondering if anybody here has some ideas.
Adobe PDF TA2613-00_EN-GBAdobe PDF TA2633-00_EN-GB
Assuming these are a two wire sensor, I am wondering, what do the GND connections go to from the sensor (need pin number). Is it going to earth ground or something else?
"They have gone through about 5 of these cards". Yes, something is wrong! Our Automation Direct PLCs (DirectSoft DL, Do-more DL and BX) have connected to ifm products for over 20 years with great success. So something in the installation and/ or wiring? Some questions come to mind. Is it always one channel for all 5 failures? Or various channels for the failures? Is the power supply supplying 24VDC? Is the power supply powering the transmitters the same power supply powering the PLC module? Same 24VDC common? Is the power supply rated to handle the max current required? Is the power supply NOT the same power supply powering the outputs (motor contactors, solenoids, etc.)? The schematic shows the wire from the ifm connected to a "ground" terminal? The blue wire (24VDC common) of the ifm should be directly connected to the common of the power supply, whether the 24VDC common has a ground connection or not. (Perhaps this is just my mis-understanding of the schematic) Are the 24VDC wires physically separated from power wires? in the panel? in the plant? Could 32mA fuses be installed?
I did not look deep enough into the ifm TA2633 and TA2613. (our ifm transmitters required 3 and 4 wires) I see the ifm TA2633 and TA2613 can be wired as a 2-wire transmitter - if not using IO Link. But if the blue wire, pin3 is connected, it must directly connect to the power supply common, which must also connect to the PLC module common.
Hey guys thank you for the fast responses! The power supply is rated for 10A so it should be more than enough to handle all our 24VDC loads, and yeah its powering transmitters as well as the plc and yes same common. I just had the bring the blue wire to common 🤞. I'm hoping that helps.
You say its "powering transmitters as well as the plc" and the power supply is rated 10A (much more than is needed for a "normal" amount of analog I/O). So if that means the power supply is also powering digital outputs, like motor contactors, solenoids, etc., then this is what could be taking out your analog module due to voltage spikes. I would suggest a dedicated power supply to power your 24VDC output loads.
You say "had the bring the blue wire to common". If this means the blue wire was connected to a machine ground screw, and not run to the power supply common terminals, then yes, this could cause problems due to difference in "ground" potentials.