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PH Detector Technology Group

LHC Gas Systems, Maintenance and Operations

Gas Systems's Operational Procedures

Procedures Common to All Gas Systems
	Action		Procedure
1	Reset an ELMB that has locked out (values not updated, zeroes):		Download the .pdf
2	Re-load the Gas Controls Application Program on the Schneider Premium PLC		Download the .pdf
3	Re-boot the Schneider Premium PLC		Download the .pdf
4	Cleaning the water XMFC in the RPC Humidifier Rack		Download the .pdf
5	Profibus Diagnostic Indications shown on VIPA type Profibus Connector		Download the .pdf
6	Pressurize the gas pipes to able to start a close-loop gas system		Download the .pdf
7	Increase gas flow in a closed-loop system		Download the .pdf
8	Control MFC oscillations (PID problem)		Download the .pdf
9	Flammable Gas Operations       ALICE       ATLAS       CMS		https://edms.cern.ch/document/880050 https://edms.cern.ch/document/933334 https://edms.cern.ch/document/889734
10	How to RESTART A GAS SYSTEM after a GENERAL L3 GAS ALARM (triggered by a gas detection head)		https://edms.cern.ch/document/930406
11	Calibration BINOS IR		https://edms.cern.ch/document/926903
12	Teledyne Trace O2 analyser		https://edms.cern.ch/document/1057077

Procedures System-Specific
Sub-system		Procedure
ALICE
ATLAS
TGC		Restarting TGC after a global stop: Before starting the system, switch on the liquid pump of N-PENTANE to build some pressure. Leave it in Force mode after the start and put back the pump in Auto mode. Don’t forget to switch on the liquefier in Manual mode and leave it manual. Disable flowcell alarm (Line 9 in RECIPE CONSTANT of Distribution module). When flowcells in/out have reasonable values, enable the alarm.
RPC		Before the system cab be restarted the high pressure buffer must be filled at least up to 500 mbar
CMS
N2 Supply Alarm		The SMS message "Bad – CMSAUX_En_PSL004" from CMS means that the N2 batteries are in use, instead of the dewars. You can check the pressure in the batteries in this link. Explanation/Screenshot of the Gas Supply Status Page > (.pdf)
LHCb
RICH1		https://edms.cern.ch/document/1056403
TOTEM