voltage at instrument terminals with respect to ground


Thread Starter


Dear all,

The field transmitter are power with 24 VDC But at terminals we get 23 vdc and At positive and instrument ground we get 24VDC and at Negative & instrument ground we get 1 VDC. This happens when instrument is connected at field.

Instrument shields are insulated at field as per Emerson installation instruction.

But at test bench, positive & instrument ground is Zero also Negative & instrument ground zero.

So, my question is Why we get voltage in positive & instrument ground at field level????