Main distribution

Electrical main power

This web page give an overview of the mains electrical distribution for the LHCb experiment. All links to the documents defining the precise layout of the power distribution network are given here after. Power consumption, granularity of the control as well as the position of all electrical equipment have been defined and are given in details in the documents here below.
Documents already available

Main electrical power distribution principle

The LHCb electrical distribution is split in two different branches with two transformers in order to avoid possible harmonics problems with PCs. The front-end electronics and the DAQ (farm and ECS PCs) are separated. Two transformers of 1.25MVA each feed the primary distribution panels (called EXD). These primary distribution panels feed the secondary distribution panels (Refurbished LEP TDM cupboards). A TDM cupboard contain a number of TDM drawers that feeds power to a group of maximum 3 racks.

In terms of control, a PLC based system controls the entire electrical distribution of the LHCb experiment. This PLC is hierarchically linked to the overall electrical control system of CERN (to the TCR). The ECS communicates with this PLC for monitoirng and control of the electrical distribution within the LHCb experiment.
The DSS (detector safety system) has an interlock based control on the primary distribution panel (EXD) outputs for cutting power in emergency cases.

The mains electrical power is limited to 10kW maximum per rack in the counting house. The in-rack distribution is made by a so called distribution box. This distribution box consists of a number of circuit breakers and Burndy output sockets to distribute power to the various equipments housed in the rack. In addition, a temporized relay is installed upstream the circuit breakers in order to deal with the high in-rush current of certain equipment (like PCs) by cascading the starting-up of the racks. 

Documents and minutes related to the electrical distribution:

EDMS:

The "Mains power requirement for the LHCb experiment" document gives the total amount of electrical power needed for all sub-detectros and sub-systems of the LHCb experiment: https://edms.cern.ch/document/473770/

The "Electrical distribution network for the LHCb experiment" document describes all details of the electrical network requirements. Rack layout, type and location of the different power outlets as well as all information for the electrical network installation are given in this document: https://edms.cern.ch/document/478224/ 

All other EDMS documents available are in this sub-project folder: https://edms.cern.ch/project/LHCB-0348/0

Other documentation:

The drawing of the mains electrical distribution principle of the LHCb experiment is available on CDD. Drawing number: LHCEB___8040 

Measurements of the rack mounted PCs for LHC experiments. Report. K. Kahle, A. Funken. 27-01-2004:   https://edms.cern.ch/cedar/plsql/doc.info?document_id=442180&version=last

Measurements of the electronic crates for LHC experiments. Report. K. Kahle, A. Funken. 18-11-2003:   https://edms.cern.ch/cedar/plsql/doc.info?document_id=442186&version=last

Meetings:

Main electrical distribution meeting on 5th of September 2003: Main Electrical Distribution meeting

Meeting about TDM, UPS and Diesel needs in LHCb: UPS+TDM meeting

Main electrical distribution meeting on 5th of November 2003: Main Electrical Distribution meeting

LHCb Experimental area meeting on 14th of January 2004: LHCb Expt Area - Power Distribution (2MW) - Status

Sub-systems and contact people

More information and links

Safety instruction 5: Emergency stops

Grounding of the equipment

Grounding of the rails

ST-EL project

Safety guide

If you have any comments and/or questions about the site's organization or its content don't hesitate to contact me by e-mail.

This page was last modified by VB on January 30, 2006.This page has been accessed number of times