Dear Sir,
We are using XTR117 as a V to I (4 to 20) convertor.
AC voltage from the field (0 - 2.5 Vac) is applied to an Op-Amp based circuit which converts it to (0 - 5Vdc) DC.
This voltage is given as an input to XTR117 to obtain 4-20.
This device is used with a testing set-up for 3 Phase CTs and Overload relays (3 devices used for 3 phases each). current in the range of 10-1200A is passed through these CTs/Overload Relays and their O/P which is 0-2.5Vac is input to this OpAmp based circuits and further to XTR117.
One fine day, when the set-up was turned on, 2 out of 3 devices failed and o/p was 0A. On replacing XTR117, desired o/p was obtained.
In order to investigate the cause of failure, we shorted I/P of Op-Amp ckt. However, o/p of 4mA and not 0A was obtained.
We are not able to determine the cause of failure.
Can you please suggest a possible cause and guide us how to go about troubleshooting so that we can take precautions.
My email Id is komal.hm@gmail.com. Please mail me in case you want the schematic so that I can revert.
Thanks,
Regards,
Komal Marathe.
