aLIGO LHO Logbook

LHO VE

kyle.ryan@LIGO.ORG - posted 17:44, Tuesday 02 August 2016 - last comment - 09:52, Wednesday 03 August 2016(28821)

Corner Station Vent/Purge Air (notes)

1605 hrs local -> Dew point measured at HAM6 check valve exhaust <-31C. 

1630 hrs. local -> Kobelco running colder than normal (also noticeably quieter?) 

As found "LOADED" temps (manual coolant valve at the exit of the 2nd stage was 1/4 turn open)

1st STAGE DISCHARGE TEMPERATURE 276F 
2ND AIR SUCTION 79F 
2ND AIR DISCHARGE 257F 
LUBE OIL 91F  

10 minutes after closing closing manual coolant valve 1/8 turn "LOADED" temps

1st STAGE DISCHARGE TEMPERATURE 288F 
2ND AIR SUCTION 81F 
2ND AIR DISCHARGE 280F 
LUBE OIL 108F 

Corner Station chilled water set point @ 44F (as per Bubba - normal is 48F) 

Compressor UNLOAD-LOAD cycle time = 1 minute 17 seconds 

Drying Tower switching cycle time = 4 minutes 56 seconds

Comments related to this report

kyle.ryan@LIGO.ORG - 05:29, Wednesday 03 August 2016 (28830)

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Forgot to mention -> Compressor loads when receiver tank pressure is @ 80 psi and unloads @ 120 psi

kyle.ryan@LIGO.ORG - 05:34, Wednesday 03 August 2016 (28831)

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UNLOAD-LOAD cycle time is time between beginning of UNLOADs

kyle.ryan@LIGO.ORG - 09:52, Wednesday 03 August 2016 (28839)

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Mystery solved!  Bubba double checked and discovered that the current Corner Station chilled water is 38F!  This now explains everything.  I closed the manual valve mentioned above a "smidgen" more this morning and the LUBE OIL TEMP is now ~120F.  The other (air) temperatures are still too low but I believe this isn't a threat to the machine but more likely makes the water removal that occurs in the compressor less effective.  The measured dew point down stream of the external drying towers is still good regardless.