Water leak detection at LHCb Detection of cooling water leaks below electronic racks

1. Water leak detection at LHCb Detection of cooling water leaks below electronic racks

2. Counting House Three levels

3. JMB-29-09-2004 UX85-SALLE DE COMPTAGE Slight slope towards one side

4. Lowest point of the barrack Sensor cable Sensor cable

5. Leak Detection The sensing cable has two insulated wires and two conductive polymer coated electrodes. A small DC voltage (5-9 volts) is applied to the sensing cable, and internal resistors limit the current flow through the sensor cable loops to approximately 75 microamps. The actual amount of current flowing is monitored by measuring the voltage drop (V1) across an internal reference resistor. If a spill occurs, additional current will seek the path of least resistance and flow across the leak. This results in increased current flow through the reference resistor. The resultant increased voltage drop across the reference resistor signals the module to turn on the alarm. Continuity Monitoring If the cable is broken, no current will flow in the loop. The voltage across the reference resistor decreases to zero and the internal circuitry recognizes this as a continuity fault. Leak Location After a leak has been detected, the circuitry in the module is automatically reconfigured into the locating mode. The digital readout of the location is generated by measuring the voltage drop along the sensing cable between the leak and the module. The voltage drop is linear and proportional to the leak location. A different scaling factor is applied for feet, meters, or zones. Leak detection is accomplished by monitoring the voltage across an internal reference resistor. Leak location is determined by measuring voltage drop along the cable from the module to the leak.

7. Basic System Locating system With its internal alarm relay and front panel LED status indicators, the TTSIM-1A can be used as a stand-alone leak detection alarm or it can be connected to TraceTek SIM network, Distributed Control System or Building Management System The leak detection event is logged to an event history file and all status and event information is made available via RS232/RS485 MODBUS to any host PLC or plant or building automation sys-tem.

8. TT-NRM Network Relay Module DescriptionThe TraceTek® TT-NRM Network Relay Module provides the capability to add up to 320 individual alarm relays to a TraceTek TTDM-128 / TTSIM leak detection network. The TT-NRM communicates with the TTDM-PLUS/128 via the same RS-485 network used for TTSIMs. The TT-NRM can be installed in a wide variety of configurations, allowing many leak detection system layout possibilities. ExpandableThe TT-NRM is supplied as a base unit (with power supply, communications interface, DIN rail and end blocks) and separate relay modules. Each relay module contains 2 independently addressable relays. Up to 16 relay modules can be installed on each base unit, and up to 10 base units can be connected to a single TTDM-PLUS. The leak detection network can be expanded at any time with minimal effort.

10. Product characteristics Cable diameter 0.24 in. (6.0 mm) nominal Cable diameter with connecter 0.52 in. (13 mm) nominal Continuity and signal wires 2 x 26 AWG with insulation of fluoropolymer Sensing wires 2 x 30 AWG with jacket of conductive fluoropolymer Carrier Fluoropolymer Cable weight (50-ft length) 2.3 lb Technical Information Breaking strength 160 lb Cut-through force >50 lb with 0.005 in. blade; crosshead speed 0.2 inch/minute Abrasion resistance >65 cycles per UL 719 Maximum continuous operating temperature Sensing cable: 194°F (90°C) Cable connectors: 185°F (85°C) Chemical resistance Cable functions normally after Trichloroethylene (100%) exposure in accordance with Sulphuric acid (98%) ASTM D 543 at 77°F (25°C) Hydrochloric acid (37%) for seven days: Hexane (100%) Methanol (100%) Sodium hydroxide (10%) Xylene (100%) Aqua regia Note: Prolonged exposure to concentrated ketones may cause temporary reduction of sensitivity; consult factory. Radiation resistance Cumulative radiation exposure of 10 megarad gamma radiation over design life of 30 years.

11. TT3000 TraceTek Sensing Cable for Conductive Liquids TraceTek TT3000 sensing cable detects the presence of conductive liquids at any point along its length. Most acids and bases and even deionized water can be sensed and located. Installed with a TraceTek alarm and locating module, the cable senses the presence of fluid, triggers an alarm, and pinpoints the location. Distributed sensing TT3000 sensing cable provides distributed leak detection and location over a wide range of areas. The cable is availablein a variety of lengths to provide as much coverage as needed. Design flexibility TT3000 sensing cable is available with factory-installed metal connectors that plug together. The measurement circuit is not dependent upon the conductivity of the leaking fluid. Therefore, the same cable will detect a wide range of fluids without special design considerations or calibration. The cable is designed for a variety of applications, including floor surfaces, subfloors,equipment locations, pipes, storage tanks, and trenches. The cable is small, lightweight, and flexible, allowing easy installation. The smooth design allows quick drying. Advanced technology Raychem’s conductive-polymer technology and fluoropolymer construction make TT3000 sensing cable mechanically strong and chemically resistant. The cable is constructed of two sensing wires, an alarm signal wire, and a continuity wire embedded in a fluoropolymer carrier rod. This rugged construction exposes no metal, and enables the cable to be reusable even in corrosive environments.