DSS DSS Detector Safety System Safety of Hardware

DSS • DSS – Detector Safety System – Safety of Hardware NOT personnel – Hard wired reaction – computer only monitors • Turns OFF hardware when – Level 3 alarm > fire – Crash buttons in CSM Control Room – Sensors in each rack alarm • Smoke • Temperature > 40 C • Tested CMS DSS Monday 26/10/2009 • Pushed CRASH buttons in CMSCR • Observed that the breakers for the CSC OPFC modules were tripped off by DSS • Observed that ‘most’ turbines in UXC turned OFF • Improvements to be made and a follow up test conducted - date TBD but ~ 1 wk – Need to define our criteria for test 12/16/2021 CSC DSS Status Report by Fred B. 1

DSS Reviews • • CMS has had a series of reviews of DSS People in attendance have been Armando, Dick, Petr and myself as CSC representative Participants learned a great deal about what the DSS system is and does and what it should do. (and what it does not do) CSC had a specification for DSS with reguards to CSC – but now needs to update this specification – What alarms should DSS in our racks respond to – What actions should DSS take for each possible alarm – What time delay should be set for each action 12/16/2021 • • Proposed Reactions >> General reaction for a level 3 alarm – Immediately notify CSC-DCS vial DIP • – CSC-DCS shuts down all HV and LV (top DCS button to OFF) After 15 second delay • • Turn off OPFC breakers in S 4 Turn off HV – – • Trip rack for ME 1/1 CAEN Trip 2 racks for UF HV system Reaction for DSS alarm within a rack – UXC • Trip off pre-determined OPFC breakers • Trip off HV rack (ME 1/1 or UF) – S 4 Same as level 3 for S 4 F 04 – S 1 standard CMS reaction for HV, FED and TF racks – S 2 • Level 3 shutdown • standard CMS reaction for computer racks – Surface (local DAQ) – standard CMS reaction CSC DSS Status Report by Fred B. 2

Other Points • CSC-DCS and the DSS system are intertwined – Want CSC-DCS to know a DSS action will take place and make a ‘softer’ intervention • – • • • DSS in each rack has – – – • Immediate DIP message and 15 sec time delay on DSS DCS monitored temperature sensors could turn off hardware before the DSS trip level is reached. 45 min expected to turn on after DSS total shut down. Program from c. DCS • should now work. Silvest by hand took 2. 5 hours pushing touch screen. The breakers for the OPFCs cannot be turned on by any other than an electrician - this is a legal requirement. So currently one person, Silvest, can turn them back on. Resetting requires opening the armoirs, making internal measurements. 12/16/2021 Smoke detector (not optimal) Temperature sensor (not optimal) Each rack DSS has 4 unused inputs We have suggested that thermal sensors be added to each rack and placed within the rack volume – – • between crates On manifolds We could suggest that water flow information could also be added here For each alarm within the DSS system – – Many actions can be defined Each action can touch any other DSS component Each action can be time delayed Each action can be published to DIP so other systems (DCS) can monitor and react CSC DSS Status Report by Fred B. 3