I am working as maintenance engineer in power plant with GE 7FA Turbine. We have facing problems with the Exhaust frame blower. Its taking 120% current during start up and after turbine loading its going down to its design range.

Is this any thing to do with its impeler and volute position?
It is also having high vibration.

 

Of course you will get high starting current, but only for around the first 10 seconds. As you mentioned high vibration, I'm a little suspicious that it is not load related, but bad bearings on the blower. We have had a lot of problems with bearing on two blowers which only were a year old. Talk to yer local bearing supplier (SKM or someone) and see if you can get a better bearing also check the alignment on your blower. Hope this helps.

 

@Bob Johnston
I hope this message finds you

We have 88TK motors high current issue. The running motor 88TK-2 current was checked and the replacement of the 88TK-1 motor during the recent GT-2 outage was found that it was drawing a high current, Referring to the nameplate current rating attached herewith for your kind reference.
Changed over the motor from 88TK-2 to 88TK-1, and the 88TK-1 motor's running current was measured. Compared with the nameplate current rating, the running current of the 88TK-1 motor was also found high. 88TK-1 running current was monitored for one week, and the current readings remained the same.

Thank you