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VIS (IX)
ryutaro.takahashi - 19:07 Friday 16 February 2024 (28613) Print this report
Recovery of BF damper

[Washimi, Takahashi]

We recovered the BF damper from the overflow of V2 primmaly coil.

  1. Opened the side hatch at the cross tube. Locked the BF body with the EQ stoppers.
  2. Disconnected the Dsub connector for the primaly coils on the side plate of the BF. It was necessary to dismount the secondary coil of H2 temporally. Checked the resistance of the coil side. The resistance between 2-7 pins (V2) was overflow.
  3. Found the lead cable from V2 coil was cut at ~5cm from the pin side. Disconnected the coil from the Dsub connector side. Dismounted the coil bobbin.
  4. Repaired the cable. Cramped the new pin to the top of the lead cable. Connected the coil to the Dsub side. Checked the resistance. It was 10Ω. Mounted the coil bobbin.
  5. Connected the Dsub connector. Checked the signal on the medm. The V2 LVDT was working.
  6. Mounted the secondary coil of H2.
  7. Released the BF body. Closed the side hatch.
  8. Found the H2 signal was almost 0 later. It should be cheked the next time.
Images attached to this report
Comments to this report:
ryutaro.takahashi - 18:44 Wednesday 21 February 2024 (28657) Print this report

[Washimi, Takahashi]

We recovered the BF damper from the disconnection of H2 LVDT.

  1. Opened the side hatch at the cross tube. Locked the BF body with the EQ stoppers.
  2. Disconnected the Dsub connector for the secondary coils on the support ring. Checked the resistance of the coil side. The resistance between 2-7 pins (H2) was normal (11Ω).
  3. Disconnected the Dsub connector for the primary coils on the side plate of the BF. Checked the resistance of the coil side. The resistance between 2-7 pins (H2) was overflow.
  4. Dismounted the coil bobbin.
  5. Found the socket came out from the cable to the feedthrough. Repaired the cable. Cramped the new socket to the top of the cable.
  6. The lead cable from H2 coil was also cut at ~5cm from the pin side during the repair work. Repaired the cable. Cramped the new pin to the top of the lead cable.
  7. Connected the coil to the Dsub side. Checked the resistance. It was 7.8Ω. Mounted the coil bobbin.
  8. Connected the Dsub connector. Checked the signal on the medm. The H2 and other LVDTs were working.
  9. Released the BF body. Closed the side hatch.
Images attached to this comment
ryutaro.takahashi - 8:57 Friday 15 March 2024 (28862) Print this report

(Log on 14th)

[Ikeda, Washimi, Takahashi]

We applied new cabling to the primary coils for the BF damper. The lead wires were re-cabled on the side of the coil bobbin with the PEEK tie-anchor or the PEEK plate. The screws to fix the V2 coil was loose. Maybe it was a mistake when we recovered the coil. Additionally, the lead wires of the coils were fixed on the coil bobbins with an adhesive (TRA-BOND 2116).

Images attached to this comment
ryutaro.takahashi - 17:32 Wednesday 27 March 2024 (28991) Print this report

[Takahashi, Ikeda, Washimi]

We repaired the H2 LVDT for the BF damper. The pin-socket connection on the primary coil was loose because the Kapton insulation tube was too long. The tube was shortened and the pin-socket was reconnected fast.

Images attached to this comment
tomotada.akutsu - 17:39 Wednesday 27 March 2024 (28992) Print this report

The capton sleeved cables seemingly sit on the coil; shook will not move them?? The worst case would be that the sleeves just sliding off the coil, and being located in-between the primary and secondary coils. Will it not happen with this setup?

ryutaro.takahashi - 23:16 Tuesday 09 April 2024 (29158) Print this report

[Washimi, Takahashi]

We checked the resistance and inductance of the LVDT coils for the BF damper at the feedthrough flange with the flip cable.

  Before O4a This time

1 BF DPCH

1-6

2-7

3-8

4-9

 

25.3Ω/1.067mH

26.3Ω/1.066mH

25.5Ω/1.063mH

OL

 

27.1Ω/1.065mH

27.8Ω/1.072mH

26.8Ω/1.066mH

OL

2 BF DPCV

1-6

2-7

3-8

4-9

 

25.3Ω/1.062mH

24.5Ω/1.061mH

24.4Ω/1.062mH

OL

 

26.7Ω/1.062mH

26.3Ω/1.060mH

26.0Ω/1.064mH

OL

3 BF DSCH

1-6

2-7

3-8

4-9

 

24.5Ω/8.56mH

24.6Ω/8.55mH

23.6Ω/8.55mH

OL

 

27.7Ω/8.55mH

27.2Ω/8.54mH

26.2Ω/8.54mH

OL

4 BF DSCV

1-6

2-7

3-8

4-9

 

24.3Ω/8.51mH

24.0Ω/8.52mH

23.7Ω/8.52mH

OL

 

27.8Ω/8.50mH

27.3Ω/8.52mH

27.2Ω/8.52mH

OL

 

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