1. Alexei.Kuryakin@cern.ch 20/10/2009 1 PHOS Cooling status (1-20 Oct) Brief 28 Sep start cool down. Steps was: +5, -3, -10, -15, -20, -25, -30°C (by liquid). 2 interlocks happened: 1 Oct - ECV controller battery fail, fixed; 19 Oct - low pump cover temperature, fixed. PHOS cooling now work in nominal operation mode. Cooling liquid -30°C, PWO -24.5°C, FEE2 +15°C, FEE3 +16°C, FEE4 +11°C. Humidity up to 44% (PWO2), 46% (PWO3), 67% (PWO4). Liquid level ~51L (start from 63L), mainly due to temperature effect. Liquid leak ~1 L per week in PHOS-4.

2. Alexei.Kuryakin@cern.ch 20/10/2009 2 PHOS Cooling status (1-20 Oct) PHOS temperatures cooling liquid (C 6 F 14 ) FEE2FEE3 FEE4 PWO2 PWO3PWO4 Interlock 1 Oct. due to ECV controller battery failure. Fixed. Interlock 19 Oct. due to pump cover temperature (lower threshold). Fixed.

3. Alexei.Kuryakin@cern.ch 20/10/2009 3 PHOS Cooling status (1-20 Oct) Liquid level going down, now 51 L Leak ~1 Liters per week + temperature effect +5 ° C -3 ° C -25 ° C -10 ° C -30 ° C -20 ° C -15 ° C Interlock 19 Oct by pump cover temperature Interlock 1 Oct by ECV controller battery, +25°C

4. Alexei.Kuryakin@cern.ch 20/10/2009 4 PHOS Cooling status (1-20 Oct) PHOS-2 humidity FEE2 PWO2

5. Alexei.Kuryakin@cern.ch 20/10/2009 5 PHOS Cooling status (1-20 Oct) PHOS-3 humidity FEE3 PWO3

6. Alexei.Kuryakin@cern.ch 20/10/2009 6 PHOS Cooling status (1-20 Oct) PHOS-4 humidity FEE4 PWO4

7. Alexei.Kuryakin@cern.ch 20/10/2009 7 PHOS Cooling status (1-20 Oct) Pump cover temperatures Pump2 Pump1 Interlock by pump cover temperature threshold was -10°C Pumps works in round-robin order (8 hours) to equalize working time

8. Alexei.Kuryakin@cern.ch 20/10/2009 8 PHOS Cooling System status (20 Oct) Concept scheme (just to remind) Evaporator (suction header) Condensing (discharge header) 4 Compressors Freon R404A receiver Water condenser for freon cooling Heat Exchanger R404A   C 6 F 14 Electric Control Valve ECV controller 2 Pumps Receiver tank 65L C 6 F 14 Cooling server alidcscom252 LAN2 DCS server alidcscom072 phs_top project PVSS LAN1 DIM 4 compressors, 2 pumps, 3 heaters, 2 valves, Electric Control Valve + controller, fan, 3 pressure + 14 temperature sensors, liquid level sensor, thermo/oil/pressure relays, funless industrial computer, I-7000 serial remote data acquisition modules PHOS Control unit (ADC, DIO etc) RS-485 Feedback temperature sensor

9. Alexei.Kuryakin@cern.ch 20/10/2009 9 PHOS Cooling System status (20 Oct) Stabilization algorithm PHOS cooling stabilization algorithm based on compressor switch on/off by feedback temperature sensor. So liquid temperature is not constant, but average temperature per control cycle is stable (±0.1°C). Control cycle should be optimized during test period (~5 parameters)

10. Alexei.Kuryakin@cern.ch 20/10/2009 10 PHOS Cooling System status (20 Oct) Safety: Alarms and Interlocks PHOS cooling plant have 3 outcome Interlocks: 1.Hardware (normal opened relay) – signal in case of cooling system power off or control computer hang 2.Software (DIM service) – signal in case of alarms, i.e. dangerous conditions (some parameter out of threshold) 3.Network (DIM service) – shows that cooling server (alidcscom252) still alive Software alarm produce interlocks by 35 conditions. Interlock mean that cooling plant halted because it could not continue safe operation. Important note: Cooling system alarms protect cooling plant against damage, but not PHOS PWO & FEE. PHOS protection is job for higher DCS level (PVSS, phs_top project).

11. Alexei.Kuryakin@cern.ch 20/10/2009 11 PHOS Cooling System status (20 Oct) Safety: Alarms and Interlocks Software alarms : 35 conditions Each alarm condition have: 1) Flag (enable/disable) 2) Timeout (milliseconds) 3) Threshold (optional parameter) Positive timeout produce temporary device blocking Negative timeout produce Interlock, i.e. fatal alarm and system HALT Interlock require shifter’s command to Reset

12. Alexei.Kuryakin@cern.ch 20/10/2009 12 PHOS Cooling System status (20 Oct) Problems and discussions 1.Leak ~1 L per week in PHOS-4, ~8 month of work (without liquid filling). 2.Cooling system ’ s Control Parameters and Alarms tuning should be done after period of test operation. 3.Phs_top (PVSS) actions on cooling plant interlocks is still under discussion and should be modified. 4.Documentation (manuals) should be written for “ cooling experts ”.