EE - Forum Styles
  • Not Answered

rosemount pressure transmitter 3051T

Dear all,
I have line pressure transmitter with model no.:3051TG4A2B21KE8D4M5Q4Q8S5B4P1T1 when i connect hart communicator 375 to it for testing,we found that the hart disconnected when the hand pump injected 30 bar.what i can do in this case.
Note:1-URV=85 bar and LRV=0bar.

2- i have 3 transmitters do the same thing.

3-I tried 3 hart devices.

4-the transmitter used for metering station that i take its values to flow computers flowboss 600.

5-at normal operation the transmitters are reading 56 bar without any problems 

5 Replies

  • If I understand your post correctly, it appears that 3 different 3051 transmitters all drop the HART communication when you apply 30 bar of pressure or above.  This type of behavior could suggest that you do not have enough power going to the transmitter.  Please verify the voltage at the terminals of the transmitter and electrical resistance of the 4-20 mA loop fall within the range shown below.  

  • In reply to Michael Olivier:

    you must know that the transmitter is now having reading (56 psi) and the voltage at hart is 21.9 vdc but the hart can't communicate.
  • In reply to hashem ali:

    Please verify that that you do not have excessive loop resistance. For 21.9V DC, your loop resistance needs to be between 250 ohms and 495 ohms.
  • In reply to Michael Olivier:

    The voltage at the transmitter terminals must be at least 10.5 VDC, all the way up to 20 mA. Please confirm this is so. Make sure the power is pure DC without AC noise/ripple. A little bit of noise will upset the HART communication. Depending on your power source, the noise may increase as the loop current increases which might explain why the communication works for low pressure but not high pressure. Learn more from the field communications troubleshooting guide found here: Communication Troubleshooting.pdf
  • In reply to Jonas Berge:

    the problem os solved by luck as i connect the hart terminals as the following:
    The (+) terminal is to the (+) of the test
    The (-) terminal is to the (-) of the power not to (-) of test terminal
    Then the hart is operating properly but i need to understand what this connection means.