1. P8 cryogenic PLC problems on 25.05.2011
LHC operation daily meeting
Krzysztof Brodzinski, Serge Claudet_TE-CRG-OA

2. History P8:
11:00 - PLC problem of Cold Compressor Station (1.8 K unit)
- diagnostic + PLC replacement
13:00 - Restart of Cold Compressors and cryo recovery
15:30 - Cryo operation problem (lost of ~ 1 hour)
16:30 - Restart of Cold Compressors and cryo recovery
18:00 - PLC problem on Main Warm Compressor Station (ref. 4.5 K)
- diagnostic +PLC replacement
19:00 – Complete restart and cryo recovery
For information:
Estimated recovery time after stop of Cold Compressor  10 hours +/- 10%
Estimated recovery time after stop of Warm Compressor Station  24 hours +/- 10%
(Both estimations are applicable in case of one cryo plant supplying two sectors, applicable if immediate restart applied)
TE-CRG-OA_K.Brodzinski_

3. Localization
QSCB PLC problem on – not replaced
Radiation problem NOT possible
QSCB PLC problem on – replaced
Radiation problem NOT possible
QURCB PLC problem on – replaced
Radiation problem possible
QURCB PLC problem on – replaced
Radiation problem possible
Equipment not in operation – one cryo plant supplies two LHC sectors
Detailed explanation of the problems origin should be given by EN/ICE experts
TE-CRG-OA_K.Brodzinski_

4. (C. Theis & co-workers, EDMS 735075)
Localization
(C. Theis & co-workers, EDMS )
US85
QURCB PLC localization
TE-CRG-OA_K.Brodzinski_

5. Recovery curves TS May Stop 25.05.2011 Stop 13.05.2011
TE-CRG-OA_K.Brodzinski_