BS 06626:2010 pdf download

BS 06626:2010 pdf download.Maintenance of electrical switch gear and control gear for voltages above 1 kV and up to and including 36 kV -Code of practice.
Where switching or maintenance work has to be done on equipment fed directly from a source of supply not under the control of the asset owner or the persons actually carrying out the work special care is essential. It is necessary for all parties (including the owner of the source of supply not under the control of the asset owner) to mutually agree procedures and methods of work in order to ensure the safety of persons carrying out the work, and for these agreed procedures to be incorporated in the rules and procedures for the installation.
Care should also be taken to prevent equipnient being worked on becoming energized due to the automatic or inadvertent starting of standby or emergency generators or other locally connected generation plant and sources of supply. In particulai the possibility of baclcfeeds from embedded generation sisould be taken into consideration
In addition, the asset owner should ensure that safety rules and working procedures are based on the manufacturer’s handbook, as applicable, and operational knowledge gathered over the lifetime of the asset, for the safe handling, maintenance and testing of the equipment. The asset owner should also make arrangements for monitoring to ensure that these procedures are performed effectively.
Those concerned with the organization of the maintenance of the equipment should familiarize themselves with the plant it controls and take account of any changes which might affect the operation or maintenance of the equipment. During maintenance work, all personnel should pay particular attention to warning notices andIor instructions on the equipment or set up temporarily during the maintenance procedures.
10 Equipment location
Switchgear is generally located in areas such as switchroorns and!or substations. These locations are normally separated from the routine activity of the premises and visited infrequently. Such locations should be kept locked and access restricted to authorized personnel. Periodic inspection of such locations is considered good practice to ensure that deterioration is not occurring which could affect the equipment (e.g. water ingress or build-up of debris in the location). Documented procedures should be in place to detect and rectify such faults as soon as possible
11 Isolation and access for maintenance
11.1 General
The policy to be followed in making equipment available for maintenance should always be that it should be isolated (with a means of securing the isolation utilized), proved dead where possible and immediately earthed, Dead working procedures should be the normal practice. Where live working is to be carried out, attention is drawn to Regulation 14 of the Electricity at Work Regulations 1989
NOTE See HSE publications HSG 85 Electricity at work – Safe working practices ISland HSR 25 Memorandum of guidance on the Electricity at Work Regulations 1989-21 for further information.
11.2 Procedures
No electrical conductor should be regarded as being safe unless it has been isolated, proved dead where practicable, discharged to earth and, where necessary. earthed at all points of supply. It is essential that earth(s) are applied only after the conductor has been proved dead at the point of application.
Precautions should be taken to ensure that the isolated equipment cannot be re-energized from a high voltage or a lower voltage source of supply (e.g. backfeeds from t,ansformers o’ other connected generation equipment). Precautions should be taken to ensure that any earth connection, applied as part of the safe system of work, Is not inadvertently removed. This can be achieved with warning notices Of, preferabI locks. If locks are used, they should have a unique key and the key should be under the control of the person carrying out the work.
If a circuit breaker is used to povide the earth connection, it is imperative that all trip facilities are disabled.
Voltage indicators should be proved before and after use. This should the done by means of a proving unit with low power output. If live circuits are to be used to prove instruments, adequate precautions against electric shock and short circuits should be taken. It is good practice to inspect earthing devices before every use. Howeve this might not be practicable for some devices where an integral earthing device is used. Earthing connections including leads and associated terminations need to be of adequate capacity for the duty at the point of application. The integrity of the earth connection should be verified before work commences.
Barriers preventing access to enclosures containing live conductors should normally be kept locked.
Where one person isolates and another does the work, the person responsible for isolating should demonstrate effectively to the other that the equipment is in fact dead and safe and that there are adequate safeguards to prevent re-energization.