Maintain traction and rolling stock air conditioning and ventilation systems
Overview
This standard identifies the competencies you need to carry out corrective maintenance activities on traction and rolling stock air conditioning and ventilation systems, in accordance with approved procedures. You will be required to maintain a range of air conditioning equipment and ventilation systems, which will include air flow generation, distribution and control systems. This will involve dismantling, removing and replacing faulty or damaged components such as Heating Ventilation Air Conditioning (HVAC) modules, compressors, condensers, evaporators, fans, pumps, heat exchangers, valves, couplings, ducting and trunking, heaters, filters, and control devices such as thermostats, relays, timers and switches. You will be expected to apply a range of dismantling and assembly methods and techniques, such as proof marking/labelling of components to aid the reassembly, dismantling components requiring pressure techniques, torque loading, and setting, and aligning and adjusting components. The term traction and rolling stock used in this standard applies to passenger, freight and on-track machines (OTM). Where it is relevant these standards also apply to traction and rolling stock that has been fitted with the European Train Control System (ETCS).
Your underpinning knowledge will provide a good understanding of your work and will provide an informed approach to applying maintenance procedures on traction and rolling stock air conditioning and ventilation equipment. You will understand the dismantling and reassembly methods and procedures, and their application. You will know how the equipment functions, the purpose of the individual components and associated defects, in adequate depth to provide a sound basis for carrying out the maintenance activities, correcting faults and ensuring that the repaired equipment functions to the required specification and remains compliant with all standards and regulations. You will also have sufficient knowledge of these components to ensure that they are fit for purpose and meet the specifications, thus providing a sound basis for carrying out reassembly.
You will be required to demonstrate safe working practices throughout and will understand your responsibility for taking the necessary safeguards to protect yourself and others in the workplace.
Performance criteria
You must be able to:
P1 maintain safe working practices and comply with all relevant health and safety regulations, directives, and guidelines
P2 follow the relevant system maintenance schedules to carry out the required work
P3 carry out the system maintenance activities within the limits of your personal authority
P4 carry out the system maintenance activities in the specified sequence and in an agreed timescale
P5 report any instances where the maintenance activities cannot be met or where there are identified defects outside the planned schedule
P6 complete relevant system maintenance records and pass them on to the appropriate person
P7 dispose of waste materials in accordance with safe working practices and approved procedures
Knowledge and Understanding
You need to know and understand:
K1 the relevant health and safety regulations, directives, guidelines, and safe working practices and procedures defined by your organisation, as appropriate to the activity and your working area
K2 the isolation and lock-off procedures or permit-to-work procedure that applies to the system being worked on (such as electrical isolation, locking off switchgear, placing of maintenance warning notices, proving the isolation has been achieved and secured)
K3 the specific health and safety precautions to be applied during the maintenance activity, and their effects on others
K4 the hazards associated with carrying out maintenance activities on air conditioning equipment (such as handling oils, greases, stored pressure/force, misuse of tools, using damaged or ill-maintained tools and equipment, not following laid-down maintenance procedures), and how to minimise them to reduce any risks
K5 the restrictions in place when working on equipment which contains refrigerant
K6 the classification of different voltage levels and the authority requirements for working on them
K7 what constitutes a hazardous voltage/current and how to recognise victims of electric shock
K8 how to reduce the risks of an electric shock (such as insulated tools, rubber matting and isolating transformers)
K9 the importance of wearing protective clothing and other appropriate safety equipment (PPE) during the maintenance process
K10 how to obtain and interpret drawings, specifications, manufacturers' manuals and other documents needed in the maintenance process
K11 the procedure for obtaining replacement parts, materials and other consumables necessary for the maintenance
K12 company policy on the repair/replacement of components during the maintenance process
K13 the sequence to be adopted for the dismantling/reassembly of various types of assemblies
K14 the methods and techniques used to dismantle/assemble air conditioning equipment (such as release of pressures/force, proofmarking, extraction, pressing, alignment)
K15 methods of checking components are fit for purpose, how to identify defects and wear characteristics, and the need to replace 'lifed' items (such as filters, seals and gaskets)
K16 the importance of recording the serial numbers of removed and newly fitted components affecting the rolling stock asset tree how to make adjustments to components/assemblies
K17 the methods and principles used in leak detection systems
K18 the principles of how Heating Ventilation Air Conditioning (HVAC) units/modules function
K19 the principles of how the ancillary equipment functions, its operation sequence, the working purpose of individual units/components and how they interact
K20 basic applications of different heating systems (such as radiators, in line duct heaters, skirting heating, fan coil, convectors, storage pipe heaters and air handling units)
K21 the correct system operating ranges, including temperature and pressures
K22 the principles of how high and low system pressures function
K23 how to make adjustments to components
K24 how to check that tools and equipment are free from damage or defects, are in a safe and usable condition, and are configured for their intended purpose
K25 the generation of maintenance documentation and/or reports following the maintenance activity
K26 the equipment operating and control procedures to be applied during the maintenance activity
K27 how to use lifting and handling equipment in the maintenance activity, following safe working practices
K28 the problems associated with the maintenance activity, and how they can be overcome
K29 the organisational procedure to be adopted for the safe disposal of waste of all types of material
K30 the extent of your own authority and to whom you should report if you have problems that you cannot resolve
Scope/range
Scope Performance
The following activities will be carried out during the maintenance activity:
- plan and communicate the maintenance activities to cause minimal disruption to normal working
- obtain and use the correct issue of company and/or manufacturers' drawings and maintenance documentation as well as the correct version of any maintenance software tools required
- adhere to procedures or systems in place for risk assessment, control of substances, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
- ensure correct authorization to work on air conditioning system are in place
- ensure the safe isolation of equipment (such as mechanical, electricity, heating, and air sources)
- provide and maintain safe access and working arrangements for the maintenance area
- warn others in the maintenance area if they are at risk of injury from the system being tested
- carry out the maintenance activities using appropriate techniques and procedures
- re-connect and return the system to service on completion of the maintenance activities
- dispose of waste items to comply with environmental protection guidelines and ensure the work area remains safe
Types of equipment, on which maintenance activities may be carried out, include:
- air conditioning system
- temperature control system
- heaters
Maintenance techniques, as appropriate to the equipment being maintained, include:
- marking/labelling of components
- dismantling equipment to unit/sub-assembly level
- dismantling units to component level (as applicable)
- checking components for serviceability
- replacing damaged/defective components
- replacing all `lifed' items (such as filters, seals)
- setting, aligning and adjusting replaced components
- tightening fasteners to the required torque
- correct fitting of locking devices
- making `integrity' checks before powering up system
- testing the system for leaks
- functionally testing the completed system
Air conditioning/heating components, on which maintenance activities may be carried out, could include:
- motors
- ducting/trunking
- manifolds/flanges
- matrix's
- thermostats
- dampers
- silencers/attenuators
- insulation
- pumps
- vents/diffusers
- gaskets/seals
- electrical connectors
- valves
- gauges/indicators
- timers
- control relays
- chilled beams
- filters
- sensors
- safety devices
- compressors
- condensers
- pipework
- switches
- evaporators
- couplings
- heaters
- HVAC modules
- fans (supply and extraction)
Maintenance activities on air conditioning and ventilation systems may need to comply with the following:
- organisational guidelines and codes of practice
- equipment manufacturer's operation range
- BS, ISO and/or BSEN standards
- company standard operating procedures (SOP's)
- documents such as technical procedures, vehicle maintenance instructions, vehicle overhaul instructions, workshop overhaul standards specifications
Types of paperwork/records that need to be completed and passed to the appropriate people could include:
- job cards
- permits to work/formal risk assessment and/or sign-on/off procedures
- maintenance log or report
- company-specific documentation
- electronic records