KAGRA Logbook

FCL (Air)

shinji.miyoki - 5:35 Saturday 09 November 2024 (31557)

3 Heaters stopped at EYC 1F area

During the repair of the water pump system in the EY area, I changed the heater/cooler/FFU operation at EYV because all FFUs and the air conditioner were operated simultaneously with heaters having a power of ~ 1kW as,

off the air conditioner,
off 9 of 10 FFUs
off small heaters of ~ 600W
on Sunrise heater at the level 2 (~ 900W).

I kept this situation for the weekend.

On the other hand, I recovered the 4 heaters (one: Delonghi, and 3 Sunrise heaters) condition at the EYC 1F area after the off of all TMP/DRY pumps because of the reoperation of the cryocoolers. However, the 3 heaters that were powered by the same voltage inverter stopped maybe because of the breaker trip of this voltage inverter (from 200V to 100V) for 3 heaters. Before, 3.3kW (1.2kW for 2 Sunrise heaters and 900W for one Sunrise heaters) was loaded in this voltage inverter. 1.5kw for the Delonghi heater was separately powered by other power route. After, I loaded 3.6kW (1.2kW for 3 heaters) while reducing the heater power from 1.5kW to 900W for the Delonghi heater. Then the breaker in the voltage inverter seemed to trip.

The temperature at EYC seemed to reduce by 1 C compared with before. I am now asking Takahashi-san about the possibility of operating the heater for the Colgate tube for the VIS adjustment.

Comments to this report:

shinji.miyoki - 7:59 Saturday 09 November 2024 (31558)

Temp and GAS position status at 8:00 on 9th Nov.

I changed the heater power at EXV from Lv.2((900W) to Lv.3(1.2kW) to warm up.

Images attached to this comment

31558_1731106658_Screenshot from 2024-11-09 07-55-39.png

shinji.miyoki - 7:25 Tuesday 12 November 2024 (31592)

Around 10 a.m., the tripped breaker was recovered, and two sunrise heaters were also recovered at level 2. On the other hand, a new voltage converter (200V—100V) was prepared for one sunrise heater, and it was also operated at level 2.

I changed level 2 to level 3 around 7 p.m. to accelerate the temperature recovery in the EYC 1F area.

For EYV temp adjustment, I tried level 2 (900W) and 3(1.2kW) heating power several times and concluded that level 2.5 is necessary to keep F0 GAS around zero. I will ask the technical staff for 150W heating power by using a small heater prepared in EYV.

Images attached to this comment

31592_1731363626_Screenshot from 2024-11-12 07-20-15.png

shinji.miyoki - 11:01 Saturday 23 November 2024 (31741)

~ 100W heater power was added in EYV at ~ 15:30 on the 22nd. Then, the F0 position increased to zero area.

The EY BF position increase stopped because of Takahashi-san's heater temperature reduction.

By the way, we have never(?) stopped several FFUs at TMSXY to check their influence on sensitivity. If trans-beam data is used in the present alignment control, is it better to try to turn off and on FFUs?

Images attached to this comment