1. Alexei.Kuryakin@cern.ch 01/10/2009 1 PHOS Cooling status (1 Oct) Incident happened (ECV failure) 1 Oct at 5 Am cooling plant failure happened: ECV (electrical control valve) controller alarm raised due to battery failure (a small battery inside controller) Compressors worked as usually, but freon didn ’ t flow because ECV was closed, so cooling liquid temperature start to increase. At 10 Am interlock blocking occurred because liquid temperature increase up to 25°C At 1 Pm after analysis problem temporary fixed: ECV switched on in manual mode and 43% opened. But that is only temporary solution: battery should be replaced to new one ASAP. PHOS cooling now working in normal operation mode.

2. Alexei.Kuryakin@cern.ch 01/10/2009 2 PHOS Cooling status (1 Oct) Liquid temperature ECV failure Normal operation Interlock on T max ECV operation in manual mode

3. Alexei.Kuryakin@cern.ch 01/10/2009 3 PHOS Cooling status (1 Oct) Pressure in evaporation tube Compressor works but no freon (vacuum in evaporator tube) Normal operation Fatal Interlock Electronic Control Valve (ECV) failure Continue in manual ECV mode

4. Alexei.Kuryakin@cern.ch 01/10/2009 4 PHOS Cooling status (1 Oct) Compressor cover temperature Compressor 3 cover raise up to 80°C Compressor 1 Compressor 2 Compressor 4 Compressor 3 ECV failure Interlock ECV work in manual mode

5. Alexei.Kuryakin@cern.ch 01/10/2009 5 PHOS Cooling status (1 Oct) PWO, FEE temperatures PWO3 FEE2 PWO2 PWO4 FEE4FEE3 Liquid

6. Alexei.Kuryakin@cern.ch 01/10/2009 6 PHOS Cooling status (1 Oct) What is ECV controller

7. Alexei.Kuryakin@cern.ch 01/10/2009 7 PHOS Cooling status (1 Oct) ECV controller diagnosis Alarm: Battery failure

8. Alexei.Kuryakin@cern.ch 01/10/2009 8 PHOS Cooling status (1 Oct) What should be done Battery should be replaced with new one inside ECV controller (access to pit required) New blocking (interlock) should be added for compressor cover temperature (need few days for programming)