1. Niels Tuning (1/9) LV status

2. Outline 1)Preventive maintenance  Fan replacement 2)Power supplies:  Clogged cooling water circuit  Water damage 3)Next steps Niels Tuning (2/9)

3. 1) Preventive Maintenance: Fan replacement CAEN: untouched Wiener LV –PFC (6x)  1 PFC (7196 0059) exploded (AC short) during the final check after preventive maintenance –Fan tray (1x) –Crate PS (1x) Wiener Tell1 Racks –Fan tray (2x) –Crate PS (4x)  1 Crate PS (7140 0023) not switch on  Retested, and seems ok  See logbook:  http://lblogbook.cern.ch/OT/3627 http://lblogbook.cern.ch/OT/3627 LHCb week 24 Feb 2014 – LV - N. Tuning (3) PFC Tell1 Rack PS

4. 2) Power supplies: history History (see Moritz’ talk LHCb week 9 Sep 2013):9 Sep 2013 –Switched on LV for commissioning week in Sep 2013 Dirty cooling circuit: (logbook 21 Oct 2013)logbook 21 Oct 2013 LHCb week 24 Feb 2014 – LV - N. Tuning (4)

5. 2) Power supplies: “verification” procedure Water spill when checking cooling circuit –3-SEP-2013: Unconnected cooling water for T1C and T2A3-SEP-2013: –4-SEP-2013:4-SEP-2013: A-side: T1A, T2A OK; T3A ERROR C-side: T1C, T2C, T3C ERROR JAN-2014: Unmounted all 6 Being tested one at the time: OK, with worries?? –17-OCT: T2C OK, with worries??17-OCT –22-JAN: T1C OK22-JAN –30-JAN: T3C OK30-JAN –12-FEB: T1A OK12-FEB –21-FEB: T2A OK21-FEB –To be done: T3A –To be done: Spare LHCb week 24 Feb 2014 – LV - N. Tuning (5)  Will order one extra spare PS

6. 3) Next steps Clogged cooling water circuit at Sep comm. week Water spill damaged LV power supplies Next: –Check carefully all 6 power supplies (long term, with load) –Buy extra spare –Replace water connectors (thanks Laurent Roy for help!) –Re-install power supplies Test at next commissioning week (~17-MAR) LHCb week 24 Feb 2014 – LV - N. Tuning (6)

7. Backup LHCb week 24 Feb 2014 – LV - N. Tuning (7)

8. 1) Preventive Maintenance: Fan replacement WienerWiener: our fans are under maintenance now –LV power supply (PFC) + fan trays –Tell1 crates fan trays –Total cost 6k CHF CAENCAEN: we wish not to touch Niels Tuning (8/9) Ken Wyllie, TB 26 feb 2013

9. Intermezzo: Fans in OT 1)CAEN HV 1)CAEN HV (2 SY1527 Mainframes): We prefer not to touch the system a)They have a lifetime of 20khours at 60 C. This corresponds to 2.3 years continuous operation at 60 C. Suppose operation at 30 C, the lifetime increases to (1.26)^3 x 2.3 = 4.6 years of continuous running. b)Actual experience suggests lifetime is longer. c)We think the risk of damage when taking apart the system is considerable. d)We will try to remove dust during LS1. 2)Wiener LV 2)Wiener LV: We wish to have the fans replaced I.PFC units (6) a)They have fans with a lifetime of 39khours at 40 C. This corresponds to 4.5 years continuous operation at 40 C (or 5.7 years at 30 C). b)At the same time, we have the chance to check/replace suspicious capacitors. c)This (simply) implies sliding out the PFC units, and does not form a big risk. II.Fan-Tray a)Lower priority, as they have longer lifetime 65 khours + easy to replace. III.Crate-power-supply of the RCM-crate 3)Wiener TELL1 3)Wiener TELL1: We wish to have the fan-tray replaced I.Fan-trays a)Lower priority, as they have longer lifetime 65 khours + easy to replace II.Crate-power-supplies LHCb week 9 Dec 2013 – LV - N. Tuning (9)

10. CAEN HV (SY1527) LHCb week 9 Dec 2013 – LV - N. Tuning (10)

11. Wiener LV I. PFC (x6): II. Fan tray: Front: Back: III. Crate Power Supply

12. Wiener TELL1 I. Fan tray: II. Crate power supplies Front: Back: