We had blackout on 20211113. Today, we recovered facilities in TAMA and found one of the turbo pumps got error.
To recover vacuum system, I firstly turned on rotary/dry pump and wait for a few minutes and open the gate valve between rotary/dry pump and turbo pump. Then I turned on turbo pump.
The error happened only for the turbo pump in the middle of arm. And it happened few minutes after I switched it on. The large noise was heard from it. The error code is E089 shown on the screen of turbo pump controller.
I checked online, the E089 indicates that rotor is outside its nominal position.