Diagnose faults in telecoms equipment

This standard identifies the competencies you need to diagnose faults in operational telecoms systems and equipment. You will carry out diagnostic tests and analyse the results of the tests to determine the root cause of the fault and its location. The telecoms equipment in this standard can be for overground or underground rail transportation systems.

You will apply diagnostic techniques, using tools and equipment in accordance with the fault symptoms, and follow fault investigation guides to pinpoint and rectify system issues. You will ensure all tools are working and equipment is calibrated. Before starting work that could affect system integrity, you will take measures to prevent harm and get necessary approvals for any system interference.

You will investigate and report faults within your authority, ensuring diagnostics are relevant and adhere to best practices and documentation. If initial diagnosis is inconclusive, you'll consider further investigation, seeking help, system restoration, or escalating the issue, making changes as needed with the right approvals. You will record evidence of faults, their safety and performance implications, and report recurrent defects.

Safety is a key theme throughout this standard. You will be able to take all relevant action to ensure the safety of yourself, others and railway operations.

P1 maintain safe working practices and comply with all relevant health and safety regulations, directives, and guidelines
P2 identify and analyse any necessary changes to safety requirements on arriving at site, including prompt reporting to the relevant person(s)
P3 review and analyse all relevant information on the symptoms and problems associated with the equipment including fault history to establish the location and nature of the fault
P4 take appropriate action to prevent the system functionality or integrity being compromised before starting any intrusive activities
P5 ensure that protection and disconnection arrangements are implemented to ensure operational safety
P6 investigate and determine the most likely causes of the faults, including as appropriate, selecting and following the appropriate fault investigation guide
P7 carry out diagnostic techniques in a manner that minimises the interference with other systems and equipment and is within the limits of your own authority
P8 select, use and apply diagnostic techniques, tools and test equipment appropriate to the symptoms of the fault to locate it
P9 investigate and confirm the fault diagnosis within the agreed time and inform the appropriate person(s) when this cannot be achieved
P10 identify and analyse the implications of the fault for other work and for safety considerations and report the implication of the fault(s) to the relevant person(s)
P11 analyse the evidence gained to draw valid conclusions about the nature and probable cause of the fault, including as appropriate, re-occurring faults
P12 record details on the extent and location of the faults in an appropriate format, including as appropriate, drawing valid conclusions on the options for rectifying the fault and the changes required to possession and protection arrangements
P13 address problems within your control and report unresolved issues

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 relevant railway possession and protection arrangements for the work site and equipment to provide a safe system of work and how to check these have been implemented
K3 how to locate and access the site
K4 how to secure the system prior to fault finding activities taking place
K5 the activities which may compromise system functionality and integrity including the operational constraints to carrying out diagnostic activities
K6 how to identify, evaluate and respond to influencing factors whilst carrying out the tests/checks, including environmental factors, site conditions and working on an operational railway
K7 the isolation and lock-off procedure or permit-to-work procedure that applies to the system (such as electrical isolation, locking off switchgear, placing of warning notices, proving the isolation has been achieved and secured)
K8 the classification of different voltage levels and the authority requirements for working on them
K9 what constitutes a hazardous voltage/current and how to recognise victims of electric shock
K10 how to reduce the risks of an electric shock (such as insulated tools, rubber mating and isolating transformers)
K11 the importance of wearing protective clothing and other appropriate safety equipment (PPE) during the testing activities
K12 hazards associated with carrying out telecom diagnostic activities (such as stored voltages, radio frequency radiation, electrical supplies, electrical/electronic interfaces, using damaged or ill-maintained tools and equipment, not following laid-down diagnostic procedures), and how to minimise these and reduce any risks
K13 how to source and interpret engineering diagrams, related specification approved manuals and other related information such as previous diagnostic information
K14 how to source and evaluate information relating to the fault, including as appropriate, eye witness accounts, re-occurring faults
K15 the types of fault diagnostic aids available and how to use them
K16 the principles of operation of the equipment to be diagnosed
K17 the relevant methods and techniques for fault finding
K18 how to locate and identify the equipment to be tested and/or checked
K19 your organisation's procedures for failure investigation
K20 what constitutes a fault and/or defect to telecoms equipment
K21 how to assess the likely risks arising from faults and/or defect and the implications involved
K22 what operational constraints could occur whilst carrying out fault finding activities
K23 the procedures and precautions to be adopted to eliminate electrostatic discharge (ESD) hazards when working with and handling electronic devices
K24 the methods and techniques for data diagnostic analysis relevant to the equipment
K25 how to select and use the correct tools and test equipment and confirm they are suitable for use and calibrated
K26 your organisation's procedures for the use, care and control of inspection tools and equipment
K27 the importance of calibrating tools and test equipment
K28 how to interpret and analyse information from measuring instruments, including as appropriate, performing calculations
K29 how to use test equipment so as to ensure true and accurate measurements are taken
K30 your organisation's procedures for the control of faults and modifications
K31 the relevant reporting lines and procedures that are approved by your organisation
K32 the limits of your own authority and responsibility and those of others involved

1. Types of health and safety legislation, regulations and safe working practices and procedures, include:

   • your organisation's safety management system
   • control of substances hazardous to health
   • safe work plans
   • track access restrictions
   • track work instructions
   • track possession
   • task risk control sheets
   • current rule book
   • regulations for working under OLE and in the vicinity of DC lines (where appropriate)
   • equipment disconnections
   • manual handling
   • reporting of injuries, diseases and dangerous occurrences
   • safety signage legal requirements
   • PPE

2. Types of site equipment locations include:

   • trackside
   • internal (such as signal box, equipment room)
   • areas to which the public have access
   • confined spaces
   • elevated structures

3. Types of telecom equipment, upon which faults may be diagnosed, could include:

   • transmission systems
   • bearer circuits
   • telecoms bearers carrying signalling circuits
   • SCADA
   • operational telephones
   • switches and systems (such as telephone exchanges & concentrators)
   • railway operational information systems
   • PA and CCTV
   • operational CCTV (such as OPO/DOO)
   • GSM-R
   • other industry specific telecom equipment

4. Types of tools and equipment used, as applicable to the equipment being tested to determine the fault location, include:

   • calibrated hand tools
   • un-calibrated hand tools
   • calibrated test leads/loads
   • computerised test equipment
   • test recording equipment
   • other specific telecom test equipment

5. Sources of fault diagnosis evidence could include:

   • the person or operator who reported the fault
   • equipment self-diagnosis
   • test instrument measurements
   • recording devices
   • sensory input (such as sight, sound, smell, touch)
   • equipment records
   • circuit meters
   • equipment outputs

6. Types of fault diagnostic techniques could include:

   • half-split technique
   • input/output technique
   • injection and sampling
   • six point technique
   • emergent sequence
   • unit substitution
   • function/performance testing
   • equipment self-diagnostics

7. Types of diagnostic aids could include:

   • investigation guides
   • logic diagrams
   • fault analysis charts (such as fault trees)
   • flow charts or algorithms
   • manufacturers' manuals
   • probability charts/reports
   • troubleshooting guides
   • computer-aided test equipment
   • electronic aids

8. Fault diagnosis activities may need to comply with the following:

   • infrastructure guidelines and standard operating procedures
   • equipment manufacturer's documents
   • BS, ISO and/or BS EN standards
   • TMTH
   • authorised test plan
   • investigation guide
   • other industry specific telecom standards/specifications

9. Types of diagnostic records that need to be completed and passed to the appropriate people could include:

   • job card
   • TMTH
   • fault log and action report
   • company reporting procedures
   • other industry specific test records