LVDT Feed Back Problem


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We are having a Frame-V gas turbine machine using Mark-V control system and now we are facing one problem related to SRV LVDT feed back differential trouble alarm. this alarm is coming and become normal after some seconds. we checked both LVDT feed back, and found that one LVDT feed back is fluctuating between 1.6V TO 2 V. the good one is always showing 2V. also we checked the excitation voltage and tightness of the LVDT core found normal.

Can anybody suggest what will be the possible cause of this voltage drop issue? and is it advisable to check in running condition, even though the Mark-V is taking feed back from the higher value (i.e.,2V)?

I wouldn't think to deeply about this. The simple answer is normally the correct one. The description sounds like two possible issues. Either:

1) the LVDT is failing so get a spare and prepare to change and re-cal or

2) there is a loose connection or wiring issue.

As your unit is running maybe you have only checked the MK5 terminals or have you checked every local junction box that is "on-base".

You will have to get out the "Turbine connection diagram" and just double check every connection with the unit shutdown. I have found crimped ends in Junction boxes were the cable just falls out of the crimp. Good luck

Average to response over some time interval, you are probably dealing with scan delay rather than a fault...

remember even self driving cars cannot current identify kangaroos!