I found primary vacuum back up pressure ITH CG1, CG2, and CG4A were unusually high this morning. They should be about 10 -20 mtorr after one night pumping, but all of thier reading were 340-350-mtorr. Thease cause the current draw on primary turbo pumps were all over 2.0A(should be about 1.0A). I let Paul closed all BVs on primary side . The pressure dropped quickly to normal range after all BVs were closed. This shows the back up line are good. The problem are from   one of  the connections  on primary BVs. I let Paul opened the BVs one by one,but the problem did not show again. Now ,the current draw on the turbo pumps are back to normal also.

I will keep monitoring the system and take a look on all KF25 clamps on BVs once I have a chance to access to ITW.