Carry out fault diagnosis on traction and rolling stock systems
Overview
This standard identifies the competencies you need to carry out fault diagnosis on traction and rolling stock systems, in accordance with approved procedures. You will be required to diagnose faults on a traction and rolling stock system involving the following interactive technologies: mechanical, electrical, fluid power or process controller, at the sub-assembly/component level. You will be expected to use a variety of fault diagnosis methods and techniques and to utilise a number of diagnostic aids and equipment. From the evidence gained, you will be expected to identify the fault and its probable cause and to suggest appropriate action to remedy the problem. 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 responsibilities will require you to comply with organisational policy and procedures for the fault diagnostic activities undertaken, and to report any problems with these activities or the tools and equipment used that you cannot personally resolve, or that are outside your permitted authority, to the relevant people. You will be expected to work with minimal supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work and will provide an informed approach to applying fault diagnosis procedures within an integrated system. You will understand the various fault diagnosis methods and techniques used and their application. You will know how to apply and interpret information obtained from diagnostic aids and equipment, in adequate depth to provide a sound basis for carrying out the activities and identifying faults or conditions that are outside the required specification. You will know about the interaction of the other associated integrated technologies, and will have sufficient knowledge to carry out effective fault diagnosis of the Integrated system. You will understand the safety precautions required when carrying out fault diagnosis activities, especially those for isolating the equipment and for taking the necessary safeguards to protect yourself and others in the workplace. You will be required to demonstrate safe working practices throughout.
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 review and use all relevant information on the symptoms and problems associated with the products or assets
P3 investigate and establish the most likely causes of the faults
P4 select, use and apply diagnostic techniques, tools and aids to locate faults
P5 complete the fault diagnosis within the agreed time and inform the appropriate people when this cannot be achieved
P6 determine the implications of the fault for other work and for safety considerations
P7 use the evidence gained to draw valid conclusions about the nature and probable cause of the fault
P8 record details on the extent and location of the faults in an appropriate format
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 specific safety precautions to be taken when carrying out the fault diagnosis of the particular engineered system
K3 the isolation and lock-off procedure or permit-to-work procedure that applies to the maintenance activities (such as electrical isolation, locking off switchgear, placing of maintenance warning notices, proving the isolation has been achieved and secured)
K4 the importance of wearing protective clothing and other appropriate safety equipment (PPE) during the fault diagnosis activities, the type of safety equipment to be used and where to obtain it
K5 the hazards associated with carrying out fault diagnosis on engineered systems (such as handling fluids, stored pressure/force, electrical contact, electrical/electronic interfaces, using faulty or damaged tools and equipment, using practices and procedures that do not follow laid-down procedures), and how to minimise these and reduce any risks
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 procedures and precautions to be adopted to eliminate electrostatic discharge (ESD) hazards
K10 where to obtain, and how to interpret, drawings, circuit diagrams, specifications, manufacturers' manuals and other documents needed for the fault diagnosis activities
K11 the principles of how the systems function, and how the various integrated systems interact with each other such as ETCS, AWS, or TPWS
K12 the various fault finding techniques that can be used, and how they are applied (such as half-split, input/output, emergent problem sequence, six point technique, functional testing, unit substitution, injection and sampling techniques, and equipment self-diagnostics)
K13 how to evaluate the various types of information available for fault diagnosis (such as operator reports, monitoring equipment, sensory inputs, history records, and condition of the equipment)
K14 how to evaluate sensory information from sight, sound, smell, touch
K15 the procedures to be followed to investigate faults, and how to deal with intermittent conditions
K16 how to use the various aids and reports available for fault diagnosis
K17 the types of equipment that can be used to aid fault diagnosis (such as mechanical measuring instruments, electrical measuring instruments, test rigs, and pressure and flow devices), and how to check the equipment is calibrated or configured for the intended use, and that it is free from damage and defects
K18 the application of specific fault finding methods and techniques that are best suited to the problem
K19 how to analyse and evaluate possible characteristics and causes of specific faults/problems
K20 how to make use of previous reports/records of similar fault conditions
K21 what procedures are in place and have to be followed for non-safety critical permitted defects
K22 the permitted defects that can be deferred until the next planned maintenance
K23 how to prepare a handover report which complies with the company policy on fault diagnosis
K24 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 should be carried out during the fault diagnostic activities:
- plan the fault diagnosis activities prior to beginning the work
- 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, COSHH, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
- ensure the safe isolation of equipment (such as mechanical, electricity, air or fluids)
- provide and maintain safe access and working arrangements for the maintenance area
- warn others in the area if they are at risk of injury from the system being tested
- collect equipment fault diagnosis evidence from system
- carry out the fault diagnostic activities using approved procedures
- disconnect or isolate components or parts of the system, when appropriate, to confirm diagnosis
- connect and restore any components after diagnostics have taken place
- identify the fault and determine appropriate corrective action
- dispose of waste items to comply with environmental protection guidelines and ensure the work area remains safe
Types of interactive technologies, on which fault diagnosis is carried out to sub-assembly or component level, could include:
- mechanical
- electrical
- fluid power
- process controller
Sources of information, about the fault, could include:
- the person or operator who reported the fault
- sensory (such as sight, sound, smell, touch)
- monitoring equipment or gauges
- equipment records/history
- recording devices
- functional test data
- other sources (such as electronic, images)
Types of fault diagnostic techniques used could include:
- half-split technique
- emergent problem sequence
- functional/performance testing
- input/output
- six point technique
- injection and sampling
- unit substitution
- equipment self-diagnostics
Diagnostic aids and equipment used could include:
- manufacturer's manual
- logic diagrams
- algorithms
- flow charts
- probability charts/reports
- fault analysis charts (such as fault trees)
- equipment self-diagnostics
- troubleshooting guides
- circuit diagrams/specifications
- software diagnostics tools for the equipment
Types of test equipment used to help in the fault diagnosis could include:
- mechanical measuring equipment (such as measuring instruments, dial test indicators, torque instruments)
- electrical/electronic measuring instruments (such as multimeters, logic probes, analysers)
- fluid power test equipment (such as test rigs, flow meters, pressure gauges)
- other specific test equipment
Fault diagnostic activities may need to comply with the following:
- organisational guidelines and codes of practice
- equipment manufacturer's operation range
- BS, ISO and/or BS EN standards
- company standard operating procedures (SOP's)
- documents such as technical procedures, vehicle maintenance instructions, vehicle overhaul instructions, workshop overhaul standards specifications
Types of records, for documenting the outcome of the fault diagnosis, could include:
- step-by-step analytical report
- preventative maintenance log/report
- corrective action report
- company-specific reporting procedure
- job cards
- electronic reports