About

PAT Pass

An independent UK study aid for electrical equipment inspection and testing, intended to support revision towards City & Guilds 2377-77.

Independent, not endorsed

This app is not affiliated with, endorsed by or accredited by City & Guilds or any awarding body. It is not an official exam, it does not contain official exam questions, and using it does not establish or certify practical competence. It is a revision aid only.

Content and review status

Content version: 0.1.0-demo
Status: Draft material — not technically approved
Questions in the bank: 12 demonstration
Reviewed release questions: 0
Source-checked draft questions: 231 · sign-off pending

The 12 demonstration questions are original material written for this app. None has been checked against a current reference publication, so no source reference is claimed for any of them, and none is eligible for the mock bank. A further 231 questions were written from the sources listed below; each is a source-checked draft awaiting technical sign-off rather than approved content, and 223 of them are available to practice. Of the rest, 5 are held because a source could not be verified and 3 are held for an editorial reason — a duplicate, or a claim withdrawn because no source states it. An editorial exclusion is housekeeping, not an unresolved source gap.

Syllabus coverage

The criteria are the qualification handbook's own, held in a register with a stable key for each one, and these figures are derived from that register rather than typed. Three things are kept apart: a lesson that mentions a subject, a question that carries a criterion, and a question that tests what the criterion asks. Only the last counts as assessed.

LO1 Definitions: 2 of 28%
LO2 Requirements and maintenance responsibilities: 6 of 612%
LO3 Electrical units: 2 of 26%
LO4 Equipment classes and protection: 7 of 716%
LO5 Inspection procedures: 4 of 416%
LO6 Combined inspection and testing: 12 of 1736%
LO7 Records: 2 of 26%

Of the 40 knowledge criteria, 35 have at least one question mapped to them — which records that an assessment exists, not that the criterion is covered, since a criterion is judged complete on its wording and its range, never on how many questions point at it — and 0 have neither a lesson nor a question. The 223 draft questions available to practice include 201 that assess a criterion and 7 mapped as related rather than assessing one; the remaining 15 are supplementary practice that carries no criterion by design, because none of them tests a criterion as written, and they are not a mapping defect. The 12 demonstration questions sit outside criterion coverage entirely: none has been reviewed against a source.

The 2 practical criteria are reported separately rather than folded into that count: they describe the practical assignment rather than the knowledge test, 0 of them are assessed here, and this app does not teach or assess practical competence.

Sources

These records are bundled with the app, so every citation stays readable with no connection. The links are supplementary.

S01
City & Guilds 2377-77 qualification handbook
City & Guilds · Version 1.2, November 2020
Unit 701/702, pages 14-18: learning outcome 1 with assessment criteria 1-2 and range (definitions, as used in the code of practice); learning outcome 2 with assessment criteria 1-6 and range (the statutory and non-statutory documents); learning outcome 3 with its assessment criteria and range (Ohm, Watt, Hertz, Ampere, Volt; Mega, kilo, milli); learning outcome 4 with assessment criteria 1-7 and its range (basic protection; fault protection: automatic disconnection, additional protection by RCDs, SELV, ES1, RLV, electrical separation; impact: cross-sectional area, length, disconnection times; factors: environment, users handling, equipment construction, equipment type); learning outcome 6 with assessment criteria 1-17 and its range (calibration, test instrument records); learning outcome 7 with assessment criteria 1-2 and range (equipment register, formal visual and combined inspection and test record, equipment labels); learning outcome 8 with its two practical criteria and ranges; test specification table (50 questions, 80% pass mark, 1 hour 45 minutes, open book); permitted reference materials; centre resource list naming Class I, Class II and Class II FE equipment; the requirement that centres deliver the qualification against the most recent edition of the IET Code of Practice
Checked 5 November 2026 · Used to establish the scope of Topic 8 and to confirm what the units outcome asks for: identify SI units, and identify their multiples and sub-multiples. No calculation criterion appears in that outcome, and the handbook is not used as proof of any formula or limit. It is also used to establish the scope of Topic 3: the wording of LO4 criteria 1-7, the LO4 range, and the fact that Class II FE is a recognised category. For Topic 4 it supplies the wording of LO5 criteria 1-4, the LO5 range (user checks; formal visual inspection; environment, users handling, equipment construction, equipment type; the preliminary inspection procedures including suitability for the environment and IP coding, intended use, isolation including IT and UPS, connections, cables and leads, checking for fake equipment and approvals marks) and the LO7 criteria and range for documentation. For Topic 6 it supplies the wording of LO6 criterion 16 (interpret results that come from testing) and criterion 17 (specify the actions to be taken with damaged or faulty equipment), the LO6 range's calibration and test instrument records, and the requirement that delivery follows the most recent edition of the IET Code of Practice — the reference for the Code's own acceptance values, which this app does not reproduce. The handbook sets the syllabus scope; it does not substantiate the technical explanations, which are cited to the other sources for each batch. Every assessment criterion for LO1-LO7, with its outcome range, was transcribed verbatim from pages 14-18 into the criterion register in criteria.js; the wording there is the handbook's, and no criterion is paraphrased from a secondary source. Its test specification table on page 13 supplies the question weighting used for prioritising content, not any technical value.
Open source
S02
PAT: answers to popular questions
Health and Safety Executive · Web guidance, updated 16 April 2025
Popular questions and worked case studies on portable appliance testing
Checked 5 November 2026 · Used for the purpose of PAT, the annual-testing myth, frequency, records and labelling, competence, and the case studies. Topic 6 uses its competence list for combined inspection and testing — the right equipment, the ability to use it properly and the ability to properly understand the test results — its statement that records and labelling are a management tool for monitoring and reviewing the scheme, and the case study in which HSE reviewed five years of its own test results before deciding further testing was not needed for certain types of equipment.
Open source
S03
Maintaining portable electrical equipment (HSG107)
Health and Safety Executive · Third edition, 2013
Paragraphs 1-19 read for the Topic 4 batch — scope, the three-part maintenance plan, competence ('suitable training, skills and knowledge for the task'), and paragraph 7: equipment used only in accordance with the manufacturer's instructions, for its intended purpose and in the environment it was designed for. Earlier batches cite paragraphs 16-22 and 34-63 and Table 1.
Checked 5 November 2026 · Used for maintenance planning, the three maintenance activities, competence, frequency as a risk judgement, monitoring and review, and repair. Topic 4 uses paragraphs 6-7 for competence and for the requirement that equipment suits its intended purpose and environment. Paragraph 14 is used for one instruction: double-insulated equipment includes equipment marked with the double-square symbol, and if that symbol cannot be seen the equipment should be assumed to be a Class I appliance. That is a conservative default supplied by this guidance, not construction evidence, and it is taught as such. Table 1's suggested intervals are not reproduced: this app states no intervals.
Open source
S05
The International System of Units (SI)
Bureau International des Poids et Mesures (BIPM) · 9th edition (2019); concise summary, version updated 2026
Concise summary of the SI, Tables 1 and 2 — the seven base units and the derived units with special names (hertz = s⁻¹, watt = J/s, volt = W/A, ohm = V/A)
Checked 5 November 2026 · Used for the names, symbols and definitions of the units, and for what each of the five quantities is. States no test limits and says nothing about test methods.
Open source
S06
Metric (SI) Prefixes
National Institute of Standards and Technology, Office of Weights and Measures · Web page, accessed 2026
Prefixes table — factor and symbol for mega (M, 10⁶), kilo (k, 10³) and milli (m, 10⁻³); Capitalization note
Checked 5 November 2026 · Used for the prefix factors and symbols, including the distinction between M and m.
Open source
S07
Writing with SI (Metric System) Units
National Institute of Standards and Technology, Office of Weights and Measures · Web page, accessed 2026
Capitalization, Plurals, Spacing, Punctuation, Decimal Point and Prefixes — symbols, spacing and leading zeros
Checked 5 November 2026 · Used for the rules that go with the symbols: capital for multiples of a million and above, no space between prefix and unit symbol, symbols never pluralised, and a leading zero for values below one. Spelling guidance follows United States practice and was not adopted for this app's prose.
Open source
S08
HyperPhysics — Ohm's Law; DC Electric Power; AC Power
Georgia State University, Department of Physics and Astronomy (R. Nave) · Web pages, accessed 2026
Ohm's law (current proportional to voltage, resistance as the ratio); DC electric power (P = VI for a resistor); sinusoidal AC power (average power VI cos φ; the distortion qualification is supplied separately by S43)
Checked 5 November 2026 · Educational reference used for the two relationships and for the reason P = VI is not the real power of every AC load. It is teaching material, not a standard: it supports the algebra and the assumptions, not any test value.
Open source
S09
Protection against electric shock
The Institution of Engineering and Technology (IET) — author John Ware · Technical article (PDF), accessed 2026; the article's own citations are to BS 7671:2008, and the edition in force now was not consulted
Basic protection and fault protection defined; protective measures; enhanced protective measure (reinforced insulation); automatic disconnection of supply; protective earthing; additional protection; recognised protective measures table; TT system and overcurrent protection
Checked 5 November 2026 · Used only for what does not depend on a particular edition: the definitions of basic and fault protection, the exposed-conductive-part definition, protective earthing and automatic disconnection as a principle, the single-fault condition illustrated in Figure 2, and the description of additional protection as a distinct measure. Its framing of RCDs as additional rather than fault protection is edition-specific and is not adopted as a general rule: current IET guidance records RCDs providing fault protection in TT systems, where the earth-fault current may be too low to operate an overcurrent device within the permitted time or at all (S25, S40). The article's own citations are to BS 7671:2008, so its enumeration of recognised protective measures (its Table 1) and the conditions it attaches to SELV/PELV and to electrical separation are treated as edition-specific and are not relied on: the question that rested on them is withheld pending corroboration against the edition in force, BS 7671:2018+A4:2026 (S27). Disconnection times and touch-voltage values are deliberately not reproduced.
Open source
S10
Electrical Installation Guide — Chapter F: Protection against electric shocks and electrical fires
Schneider Electric · Online edition (electrical-installation.org), accessed 2026
Protection against electric shock (effects of current on the body); Types of protection (basic protection by insulation, barriers and enclosures; fault protection); Class II equipment (symbol, supplementary insulation, no protective conductor connection); Extra Low Voltage (SELV, PELV, FELV); The electrical separation of circuits; Additional protection: high sensitivity RCDs
Checked 5 November 2026 · Used for the definitions of basic and fault protection, the Class II construction requirement and its symbol, the conditions that make a supply SELV, the principle of electrical separation, and the role of high-sensitivity RCDs as additional protection. It is an industry guide based on IEC 60364, not the standard itself; the app cites it only for what it states.
Open source
S11
Work using electrically powered equipment
Health and Safety Executive · Web guidance, updated 3 April 2025
Check that the electrical equipment is suitable (physically capable of the job; damp, conductive and explosive environments); Check that the electrical equipment is in good condition (switch off and unplug before checks; plug correctly wired only if competent; fuse rating from the rating plate or instruction book; plug and cable security; no repair with insulating tape or an unsuitable connector; outer cover damage giving rise to electrical or mechanical hazards; burn marks or staining); stop use and ask a competent person if concerned; Use a Residual Current Device (RCD)
Checked 5 November 2026 · Used for reduced low voltage at an introductory level, for the roles and limits of RCDs, and for the good-condition checks that belong to a visual inspection: isolation before checking, plug and cable condition, fuse rating taken from the rating plate or instruction book, unsuitable repairs, enclosure damage and signs of overheating.
Open source
S12
The RCD Handbook: BEAMA guide to the selection and application of residual current devices
BEAMA · © BEAMA Ltd 2022
1 Introduction — what RCDs can and cannot do (not a solution for all installation problems; protection never equalled by circuit-breakers or fuses alone); 1.2 principles of RCD operation
Checked 5 November 2026 · Used for how an RCD detects residual current, for the fact that the residual-current function does not itself provide overcurrent protection (an RCCB, in the terms current IET guidance uses — S40), and for the relationship between RCDs and fuses or circuit breakers. It is a trade-association technical guide, not a standard, and its statements about RCDs generally are read as statements about the residual-current function rather than about every complete device.
Open source
S13
Ask the Engineers: questions and answers on IEC 62368-1
UL Solutions · Web page, accessed 2026 (references IEC 62368-1:2023 and IEC 61140:2016)
Clause 5 — can an ES1 output be considered SELV; comparison of ES1 with the IEC 61140 SELV definition; terms, limits and insulation requirements may differ and are not equivalent in all cases
Checked 5 November 2026 · Used only to establish that ES1 and SELV are not interchangeable terms and that the two systems come from different standards with different requirements. UL Solutions is a testing and certification organisation: this is secondary commentary on IEC 62368-1 and IEC 61140, not an IEC publication and not the standard text.
Open source
S14
An introduction to IEC 62368-1, the safety standard for ICT and AV equipment (manufacturer technical paper)
Bel Fuse Inc. · Technical paper, accessed 2026
Hazard Based Safety Engineering — energy sources classified into three levels by magnitude and duration; effects on the body and on combustible materials
Checked 5 November 2026 · Used for the principle that ES1, ES2 and ES3 classify energy sources by their potential to cause harm, and that the levels are not equipment classes. The numerical limits it quotes are deliberately not reproduced. Bel Fuse is a component manufacturer: this is secondary explanatory material about the standard, not an IEC publication.
Open source
S15
Protection classes for power supplies: a manufacturer's explanation of Class I, II and III
XP Power · Technical blog, accessed 2026
IEC protection classes (Class I, Class II, Class III); Earthing and insulation (protective earthing, functional grounding); Class distinctions — enclosure conductive or not; Class III defined by supply from a safe energy source
Checked 5 November 2026 · Manufacturer documentation used for plain-language definitions of the three classes, the distinction between protective earthing and functional grounding, and the point that Class II construction is defined by the insulation system rather than by the enclosure material. XP Power is a power-supply manufacturer: this is secondary commentary on the IEC equipment classes, not an IEC publication.
Open source
S16
Earth leakage (Wiring Matters, issue 85, May 2021)
The Institution of Engineering and Technology (IET) — author Michael Peace · Online article, May 2021
What is earth leakage current — protective conductor current under BS 7671; equipment requiring a functional earth, which is different from a protective earth
Checked 5 November 2026 · Used for the distinction between functional earthing and protective earthing, and for the fact that electronic equipment can require a functional earth while its shock protection comes from elsewhere. It states BS 7671 regulation numbers that this app does not reproduce.
Open source
S17
Maintaining portable electric equipment in low-risk environments
Health and Safety Executive · Leaflet INDG236 (rev3), published 09/13
User checks (carried out before use with the equipment disconnected; lead, plug, joint, grip, enclosure, overheating, storage conditions and trapped cable); Visual inspections (knowledge needed, the four considerations, internal plug checks where possible, and 'for equipment/cables fitted with moulded plugs only the fuse can be checked'); Portable appliance test (greater knowledge, results indicate safety at the time of test only); recognising, removing and repairing damaged equipment
Checked 5 November 2026 · The primary source for Topic 4's account of what a user check covers, what a formal visual inspection adds, the competence each needs, and the limits of a moulded plug. Topic 6 uses it for the statements that the person testing should know how to interpret the results, that testing indicates safety only at the time of the test, that the person testing should not decide when the next test is due, that equipment may be labelled with the result and date of the test, and that damaged or faulty equipment is removed from use without delay and repaired by someone competent or disposed of. Its suggested intervals in Table 1 are deliberately not reproduced.
Open source
S18
Placing UKCA or CE marked products on the market in Great Britain
Department for Business and Trade and Department for Business, Innovation, Science and Trade (GOV.UK) · Guidance, last updated 21 August 2026
Introduction — 'UKCA and CE markings demonstrate that the manufacturer believes that their product meets the relevant product requirements'; Manufacturer responsibilities, including indicating identification details (name, trade name or trademark, and postal address) and drawing up technical documentation
Checked 5 November 2026 · Used only for what a conformity mark does and does not establish: it is the manufacturer's declaration of belief in conformity, and the manufacturer is separately required to give identification details. It is not used as evidence about the condition of any particular item.
Open source
S19
IEC 60529: Degrees of protection provided by enclosures (IP Code)
International Electrotechnical Commission (IEC) · IEC 60529:1989+AMD1:1999+AMD2:2013 CSV, edition 2.2
Scope only: the standard applies to the classification of degrees of protection provided by enclosures for electrical equipment. The standard text was not accessed — only the IEC's own catalogue record of the publication was read.
Checked 5 November 2026 · Used only to establish that ingress protection is classified by an enclosure rating published as IEC 60529, and that the code itself is the manufacturer's declared classification. The meaning of the individual digits is not reproduced and is recorded as a verification gap.
Open source
S20
PAT testing of equipment having high protective conductive ('leakage') current
The Institution of Electrical Engineers (now the IET) — IEE Wiring Matters · Autumn 2005 issue, pp 15-17
Whole article: why an insulation test may not be appropriate for some equipment, the protective conductor/touch current measurement as an alternative, Table 2 test summaries, and Tables 3-4 on high protective conductor current.
Checked 5 November 2026 · Historical guidance, treated as historical. It is never used on its own to establish a current testing requirement or method: every question resting on it alone is held pending verification and excluded from practice, and the Topic 5 lesson statements it supports are flagged in place. No link is offered because a stable archive address for this 2005 print issue was not verified.
No stable link verified for this source.
S21
Electricity at work: Safe working practices
Health and Safety Executive · HSG85, third edition, published 2013, ISBN 978 0 7176 6581 5
Working dead: paragraphs 47-59 — identification, disconnection from every source, stored charge, secure isolation and lock-off, notices, proving dead, earthing, adjacent live parts.
Checked 5 November 2026 · Used for the principles of safe isolation and proving dead, and for what isolation must achieve. It is not a step-by-step procedure: the current Code of Practice's isolation procedure was not accessed, so none is reproduced here.
Open source
S22
PrimeTest 250+ Operating Instructions
Seaward Electronic Ltd · Part number 403A556, revision 2
Model-scoped only: important information and warnings, the separate Class I, Class II, mains cord and extension lead test sequences, factory set pass limits, the changeable CLI leakage limit in setup, and the service and calibration statement.
Checked 5 November 2026 · Cited only as that model's own instructions. No setting, limit, sequence or calibration statement from it is generalised to other instruments, and no numerical value is reproduced in content.
No stable link verified for this source.
S23
The Electricity at Work Regulations 1989 (SI 1989/635)
The National Archives (legislation.gov.uk) · In force 1 April 1990; latest available (revised) text
Regulation 2 (interpretation: danger, injury, electrical equipment, system), regulation 3 in full — the opening exception in regulation 3(1), paragraph (a) on employers and self-employed persons, paragraph (b) on mine managers and quarry operators, and regulation 3(2) on employees — and regulation 4 (systems, work activities and protective equipment), read in full in the revised text on legislation.gov.uk.
Checked 5 November 2026 · Primary source for the legal duty behind LO2_AC4: the wording of regulations 3 and 4 is quoted, and the definitions in regulation 2 are used to explain what 'danger', 'injury' and 'system' mean in the instrument. Only those three provisions were read. Nothing here summarises the Regulations as a whole, their remaining provisions, their schedules or their enforcement, and no inspection interval, test method or acceptance value is taken from them — the instrument states none.
Open source
S24
Health and Safety at Work etc. Act 1974 (c. 37)
The National Archives (legislation.gov.uk) · Section 2, latest available (revised) text
Section 2 — general duties of employers to their employees, including subsection (2)(a) on plant and systems of work.
Checked 5 November 2026 · Used only for the general duty on employers and the 'so far as is reasonably practicable' qualification, so that the Act which frames the duty can be told apart from the Regulations made under it and from the guidance that describes compliance. Sections 3, 4, 7 and 8 were not read and are not summarised, and no enforcement, penalty or case law is described.
Open source
S25
RCDs: Selection, Types and Testing — webinar questions and answers
The Institution of Engineering and Technology (IET) · IET online guidance for BS 7671:2018 (18th Edition), accessed 2026
RCD rating and additional protection — a device rated above 30 mA cannot provide additional protection against electric shock; RCDs used for fault protection in TT systems; socket-outlet residual current devices not recognised for fault or additional protection.
Checked 5 November 2026 · Read as current IET guidance, independently of S09, for three points. First, additional protection against electric shock is a distinct function of an RCD, available at 30 mA or below, and is not the same thing as an RCD used for fault protection: the same answers state that where RCDs are used for fault protection, such as in TT systems, it may not be possible to design around them or risk-assess them out. Second, an appropriate RCD can therefore be the device that achieves automatic disconnection, and additional protection is a separate function rather than the only role an RCD can have. Third, the blanket claim fails at device level: socket-outlets containing SRCDs to BS 7288 are not recognised for the functions of fault protection or additional protection under BS 7671, which is a statement about those devices and not about RCDs as a class. It does not state the recognised-measures enumeration, the conditions for SELV/PELV or electrical separation, or any voltage limit, so none of those is attributed to it.
Open source
S26
Code of Practice for In-Service Inspection and Testing of Electrical Equipment
The Institution of Engineering and Technology (IET) · 5th edition, 2020 (ISBN 978-1-78561-966-3, 136 pages, paperback). The text was not accessed: only the IET bookshop record was read, so no content claim rests on this source.
Bibliographic record only. The IET's own description of what the 5th edition changes: requirements for electrical safety management, guidance on risk assessment, the testing needed to ensure safety in continued use, changes to acceptable test result limits and a new hierarchy of tests, inclusion of ES1 and ES2 to reflect changes to product standards, guidance on the new product classifications, updated standard references and revised model forms.
Checked 5 November 2026 · Recorded to identify the reference the qualification requires. S01 says centres must use the most recent Code edition; the IET bookshop record read lists the 5th edition of 2020. The Code's text has not been accessed, so this app does not claim to quote its tables, conditions or procedures directly. The current-source register separately supports normal-operation filter current and the distinction between touch current and protective conductor current (S32-S35); those principles are no longer held merely because S20 was historical. Unresolved checks include the current-edition high-protective-conductor-current connection requirements behind PAT-TS-010 and PAT-TS-026 (also requiring BS 7671 verification), the insulation minima and test-voltage conditions behind PAT-RI-033, the precautions behind PAT-RI-035, and the conditions attached to secondary descriptions of the Code's acceptance and RCD-testing tables. Editorially retired claims are not source gaps that acquiring this book is expected to close.
Open source
S27
Requirements for Electrical Installations — IET Wiring Regulations, BS 7671:2018+A4:2026
The Institution of Engineering and Technology (IET) and the British Standards Institution (BSI) · 18th edition incorporating Amendment 4:2026, published 15 April 2026 (ISBN 978-1-83953-972-5). The standard text was not accessed.
Current-edition status only, taken from the IET's own 'ensure you are up to date' page: Amendment 4:2026 is the current edition of the national standard for electrical installations in the UK; the transition period for Amendment 2:2022 ended on 15 October 2026, so Amendment 2 is obsolete; Amendment 3:2024 was issued as a free-to-download bolt-on PDF to the brown book and is now superseded.
Checked 5 November 2026 · Used only to establish which edition is in force, so that the gap recorded against PAT-CP-036 names the edition that actually applies rather than an unqualified note. No regulation, table, disconnection time or touch-voltage value is quoted from it, and nothing is attributed to it: neither the standard nor the free Amendment 3 bolt-on was read. The bolt-on is deliberately not used as a substitute for the current edition, because it has been superseded.
Open source
S28
Form V.1 Equipment register
The Institution of Engineering and Technology (IET) · Downloadable blank model form (PDF, 77 KB) offered on the IET's Forms and downloads page under 'Model forms for in-service inspection and testing'. The text of the PDF carries no edition statement and no issue date.
Fields as published: organisation, address and responsible person; then, per item, equipment ID number, location, equipment description and serial number, each line carrying a frequency of formal visual inspection and a frequency of combined inspection and test; a date and page numbering at the foot of the sheet.
Checked 5 November 2026 · Used as an example of the identity layer of record keeping only: that equipment is listed once, given an identifier, and has the intervals that apply to it written against that identifier. Nothing is presented as a statutory requirement, and because no edition statement appears in the form it is not called a 5th edition form anywhere in this app.
Open source
S29
Form V.2 Equipment formal visual and combined inspection and test record
The Institution of Engineering and Technology (IET) · Downloadable blank model form (PDF, 525 KB) offered on the IET's Forms and downloads page under 'Model forms for in-service inspection and testing', with numbered notes 1 to 19. The text carries no edition statement and no issue date.
Fields as published, in the form's own order: inspector and client details; equipment ID number, description, construction class, type, location, both frequencies, make, model, serial number, voltage, rating and fuse; the condition of socket-outlet, plug, flex, body and 'other', marked pass or fail; test results for continuity in ohms, insulation resistance in megohms, polarity, function and 'other'; suitable for environment (Y or N); comments; suitable for continued use (Y or N); initials. The notes state that continuity is entered with the supply lead excluded and the total in brackets, that insulation resistance is entered at 500 V d.c. with any other test voltage bracketed, that 'suitable for environment' may be entered as 'lim' where the location cannot be assessed, and that the continued-use assessment is made by the duty-holder from the recorded results and a risk-based assessment, with unsuitable equipment removed from service by the duty-holder.
Checked 5 November 2026 · Used for the separation of equipment identity, inspection observations, measured results and the decision about continued use, and for the point that the decision belongs to the duty-holder rather than the tester. Fields are cited as examples from this form, never as universal requirements. Provenance limitation recorded deliberately: note 6 still offers 'Portable, hand-held, movable etc.' as an equipment type although the author of the 5th edition states that the Code removed those categories (S31), so this form is not treated as a 5th edition form.
Open source
S30
Form V.3 Equipment labels
The Institution of Engineering and Technology (IET) · Downloadable blank model form (PDF, 38 KB) offered on the IET's Forms and downloads page under 'Model forms for in-service inspection and testing'. The text carries no edition statement and no issue date.
Two labels as published: a danger label reading DO NOT USE with a fail mark, and a safety-check label reading PASS, each with a date of check, initials and an appliance number.
Checked 5 November 2026 · Used for the third layer of documentation only: a label records that a check took place, when, by whom and on which item, and records nothing about what was observed or measured. Not presented as a statutory requirement and not called a 5th edition form.
Open source
S31
The all-new 5th Edition of the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment
The Institution of Engineering and Technology (IET) — Wiring Matters, issue 81, July 2020 · Article by James Eade, author of the 5th edition, published in July 2020 as a preview of that edition. It is the author's overview, not the Code itself.
Read in full. Quotes the Code's definition of electrical equipment — 'Any item for such purposes as generation, conversion, transmission, distribution or utilization of electrical energy, such as machines, transformers, equipment, measuring instruments, protective devices, wiring systems, accessories, appliances and luminaires'; notes that 'appliance' is defined in standards as apparatus intended for household or similar use; states that the 5th edition makes no mention of 'portable' and 'appliance' outside the preface and removes 'stationary', 'portable', 'fixed' and 'moveable' as categories, with the ability to move bearing on frequency rather than on the nature of inspection and testing; explains the shift of emphasis onto equipment not covered by another maintenance regime, including equipment wired in without a plug; describes the reclassification of protection in product standards into 'energy source classes' and ES1/ES2, that SELV is no longer a method prescribed in BS EN 62368, and that SELV remains a valid protective measure in an installation; lists the new sections and appendices.
Checked 5 November 2026 · Used for the equipment-scope and classification principles it states, and for nothing else. It is one author's preview article and does not supply the Code's other definitions, its test requirements, tables, intervals or forms, so none of those is attributed to it. The single definition it quotes is presented as quoted from the Code, not as the article's own wording.
Open source
S32
Earth leakage — how much is too much?
The Institution of Engineering and Technology (IET) — Wiring Matters, issue 85, May 2021 · Article by Michael Peace CEng MIET. Its regulatory references are to BS 7671:2018+A1:2020, so every figure in it belongs to that edition.
Read in full. Quoted definitions of protective conductor current and of leakage current; normal-operation leakage caused by filter capacitors in power supplies; the need for a functional earth, distinct from the protective earth; clamp measurement of leakage currents below 5 mA and the limits of DC measurement; the difference between insulation impedance measured in service and insulation resistance measured with a d.c. tester on an isolated circuit; RCD guidance — regulation 531.3.2 limits accumulated protective conductor current downstream of an RCD to 30 per cent of its rated residual operating current, Note 2 allows operation above 50 per cent, a 30 mA device may operate between 15 mA and 30 mA, and regulation 543.7 recognises currents above 3.5 mA as high protective conductor currents.
Checked 5 November 2026 · Used for the enduring explanation of why electronic equipment carries current to earth in normal operation and why that current is not by itself evidence of a fault. Its figures are recorded as belonging to BS 7671:2018+A1:2020 and are not carried forward: the 3.5 mA figure was later displaced by the 10 mA threshold in S33, and no figure from either article is attributed to the edition in force. It does not define touch current and states no acceptance limit for the testing of equipment.
Open source
S33
High Protective Conductor Currents in Electrical Installations
The Institution of Engineering and Technology (IET) — Wiring Matters, issue 93, November 2022 · Article by Richard Giddings IEng MIET ACIBSE. Its regulatory references are to BS 7671:2018+A2:2022, so its regulation numbers and threshold belong to that edition.
Read in full. Explains the fault-only role of the protective conductor and the second, normal-operation role created by electronic equipment and functional earthing; that filtering and power-conversion currents return through the protective conductor; that if the path is lost those currents have nowhere to flow and exposed conductive parts can rise in potential, which is itself a shock hazard; the kinds of equipment involved (switched mode power supplies, variable speed drives, lighting control and dimming, audio-visual, IT and communications); 10 mA as the threshold at which special measures are required, for an individual item or cumulatively; regulation 543.7.1.202 arrangements for an item above that threshold (permanent wiring, a BS EN 60309-2 plug with a protective conductor of at least 2.5 mm² for 16 A or 4 mm² above 16 A, or a normal protective conductor with a BS 4444 earth monitoring system); regulation 543.7.1.203 arrangements for circuits (10 mm², 4 mm² enclosed, duplicated conductors, earth monitoring, or a double-wound transformer); the instruction to consult manufacturers; reference to BS EN 60335-1 clause 13.2 and BS EN 62368-1 clause 5.7.5.
Checked 5 November 2026 · Used for the enduring principles: that high protective conductor current is a normal characteristic of some equipment, that the protective conductor must stay reliable, that an ordinary plug and socket is not an adequate connection for such equipment, and that the manufacturer's information governs the item. Regulation numbers, the 10 mA threshold and the conductor sizes are recorded as the content of BS 7671:2018+A2:2022 and are never presented as the requirements of A4:2026, which has not been read. No table from the article is reproduced.
Open source
S34
Methods of measurement of touch current and protective conductor current (IEC 60990:2016)
International Electrotechnical Commission (IEC) · Third edition, publication date 30 May 2016 (the record read is IEC 60990:2016 RLV, the redline version, which contains the standard). Edition 3 cancels and replaces edition 2 of 1999 and is listed as valid, with a stability date of 2027. The standard text was not accessed: only the IEC's own public catalogue description of the publication was read.
Catalogue description, scope and object only: measurement methods for d.c. or a.c. current of sinusoidal or non-sinusoidal waveform which could flow through the human body, and for current flowing through a protective conductor; the statement that measurements of current through networks representing the impedance of the human body are referred to as measurements of TOUCH CURRENT and that those networks are not necessarily valid for animals; the explicit statement that the specification or implication of specific limit values is not within the standard's scope, with the IEC TS 60479 series named as the source of effect information from which limit values may be derived; applicability to all classes of equipment according to IEC 61140; the exclusions (touch currents of less than 1 s duration, patient currents as defined in IEC 60601-1, a.c. at frequencies below 15 Hz, and currents above the electric burn limits); the role of the publication as a basic safety publication for technical committees; and the principal third-edition changes listed.
Checked 5 November 2026 · Used for two points and no others: that touch current and protective conductor current are distinct measurands — the first current that could flow through the human body, measured through a network representing body impedance; the second current flowing through a protective conductor — and that the standard deliberately sets no acceptance value, leaving the effects from which limits may be derived to the IEC TS 60479 series. It supports measurement principle only. Because the text, the networks and the measurement conditions were not read, no network, waveform, frequency weighting, threshold, duration or test condition is attributed to it anywhere in this app.
Open source
S35
Portable Appliance Testing: A Practical Guide
Seaward Electronic Ltd · Rev 6, © Copyright 2021. The PDF carries no edition number, publication date or issue date beyond 'Rev 6' on the back cover, so no currency is inferred from the file or from when it was uploaded. The guide states that it is not legal advice, and its appendix lists the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment 5th edition by ISBN, so the Code's requirements reach this app here second-hand at best.
Read from the PDF, using both the extracted text and the position of each block on the page so that text belonging to different headings is not conflated: the contents; classes of equipment construction, including its own statement that ES1, ES2 and ES3 replace SELV, ELV and LV; the inspection and combined inspection and testing procedure (printed pages 20-21, including which tests apply to appliance cable sets, extension leads and multi-way adaptors); the electrical tests (printed pages 24-29: earth continuity with Table B and its notes, insulation resistance with Table C and the suitability discussion on pages 26-27, the alternative/substitute leakage measurement, the dielectric strength and load tests, and the protective conductor/touch current measurement with Table E on pages 28-29); the appendix (printed pages 32-33, Table G, nominal resistance of appliance supply cable protective conductors).
Checked 5 November 2026 · Used for: the choice of continuity test current and the warning that a high test current may damage sensitive components where accessible metal is earthed for functional or shielding purposes only (page 24); the point that contact resistance at the test connections can introduce significant errors (page 24); the fact that the measured continuity value is judged against an allowance plus the supply cable's protective conductor resistance, R, whose size depends on the cable (Table B note and Table G); the suitability of the insulation test, including filters and voltage limiting devices affecting the measurement, sensitive circuits being damaged by the test, and consulting the manufacturer (pages 26-27); the requirement to insulate-test before applying mains power, the current-limited test voltage and the Class II probe placement (pages 26 and 28); the protective conductor/touch current path by construction (page 28); and the tests allocated to 3-core cable sets, 2-core cable sets, extension leads and multi-way adaptors (page 20). Values: Table B (0.1 + R, 0.1 ohm without a supply cable, the duty-holder allowance up to 0.5 ohm), Table C (1.0 MΩ Class I, 2.0 MΩ Class II and Class II FE), Table E (5 mA for both classes), the per-metre resistances in Table G and the RCD rating and trip times in Table A are reproduced in the app's lessons and questions with this source named and with the guide's own conditions attached. Table B's continuity allowance and Table E's leakage figure are corroborated by a second Seaward publication (S37, S36); Table C's insulation values are not corroborated by any source read, and are marked accordingly. The exact continuity test-current ranges are described but not given as figures, and no value here is presented as the Code of Practice's own. Conflict flagged and not adopted: the guide's statement that ES1, ES2 and ES3 replace SELV, ELV and LV, which contradicts S31 (SELV remains a valid protective measure in an installation) and S13/S14 (the ES levels classify energy sources in product standards and are not equipment classes). Edition dependency: everything the guide attributes to the Code of Practice is second-hand, and S26 records that the Code itself has not been read.
Open source
S36
5th Edition Ready PAT Testers
Seaward Electronic Ltd · Undated product and campaign page carrying a © 2026 footer, describing the tester range updated for the IET Code of Practice's 5th edition (released September 2020). It records Apollo firmware version 4.1.1, released 24 August 2020.
The PrimeTest and Apollo change lists and the '5th Edition FAQs' answers: the leakage PASS/FAIL limit increased to 5 mA for Class 1 and Class 2; an RCD test at 5x the rating for 30 mA RCDs now required; selectable earth continuity pass/fail values of 0.1, 0.2 and 0.3 ohm; a 250 V insulation resistance test added; the new Class 2 FE sequence; a long lead test; and the firmware note that updated 4th-edition Apollo units apply 5 mA to protective conductor current and 3.5 mA to touch current, where new 5th-edition products apply 5 mA.
Checked 5 November 2026 · Used for three points only: that the manufacturer summarises the 5th edition as raising the leakage PASS/FAIL limit to 5 mA for both classes; that it states a 5x rating test is now required for 30 mA RCDs; and that one of its own firmware updates still applies a different touch-current figure from its new products, which is the evidence used to show that a requirement and an instrument's configured comparison are different things. This is a manufacturer's summary and not the Code: no condition, exception or measurement method is attributed to the Code through it. Its commercial claims are not relied on — not the assertion of 5th-edition compliance, not the claim to be the only manufacturer able to make it, and not any product or training offering.
Open source
S37
How do you PAT test a long extension lead?
Seaward Electronic Ltd · Web support answer, undated, on a page carrying a © 2026 footer. It states the limit in terms of the IET Code of Practice's 5th edition, so it describes the position from September 2020 onward.
Whole answer: long extension leads commonly indicate a fail on earth continuity, producing false failures and incorrect records; the earth resistance limit for earth continuity stipulated in the Code's 5th edition allows 0.1 + R ohm with R the resistance of the cable; a table in the Code calculates R from the cable's length and cross-sectional area; and testers offering a long lead test or a limit calculator are named.
Checked 5 November 2026 · Used for one claim: that the Code's 5th-edition earth continuity limit allows 0.1 + R ohm, with R calculated from the cable's length and cross-sectional area. It is the second Seaward publication stating the same allowance as S35's Table B, which is why the continuity comparison is the best-corroborated value in the app. It does not set out the Code's table, its conditions or its exceptions, and none is inferred from it. The product features it advertises are recorded as features, never as requirements.
Open source
S38
How do I test RCDs if my tester does not have the option to do so?
Seaward Electronic Ltd · Web support answer, undated, on a page carrying a © 2026 footer. Its answer refers to table 10.5 of the Code of Practice's 5th edition.
Whole answer: when checking an RCD it is recommended that the RCD is tested with an RCD test instrument, and that the instrument should operate in accordance with the standards referred to in table 10.5 of the IET Code of Practice 5th Edition. The wording also carries a figure, but the answer does not make clear what that figure applies to.
Checked 5 November 2026 · Used for two points: that an RCD is checked with an RCD test instrument, and that the instrument should operate to the standards referred to in table 10.5 of the 5th edition. The answer's wording also carries a figure without making clear what it applies to, so nothing is concluded from it — it is not read as a device-rating limit or as anything else, and no value, test current, timing or condition is drawn from it anywhere in this app. Table 10.5 and its notes are what would settle the wording, and they have not been read. The answer's premise — that some testers lack the option — is used to separate an instrument's function from the requirement.
Open source
S39
Avoid a shock: is your protection robust? (user-check poster)
The Institution of Engineering and Technology · A4 poster PDF, undated. It refers the reader to the Code of Practice's 5th edition for further guidance, so it accompanies that edition.
Whole poster: user checks for casing and housing, flex and cables, environment, extensions and adapters, plugs and sockets, and labels, plus the instruction to look for a 'T' or test button on RCD devices and always press it before use to check the RCD trips and disconnects the equipment, and the instruction that anything failing these checks is taken out of service and labelled.
Checked 5 November 2026 · Used for the user's own RCD check — the 'T' or test button pressed before use, establishing that the device trips and disconnects — and for the poster's list of user-check items. It is a user-check instruction and supplies no limit, trip time, instrument requirement or test procedure; nothing in it is treated as a measurement.
Open source
S40
BS 7671 FAQs — Consumer Units and Protective Devices
The Institution of Engineering and Technology (IET) · Web FAQs for BS 7671:2018 (18th Edition), accessed 5 November 2026
'Do RCDs provide overcurrent protection?' — Residual Current Device is a generic term for a wide range of residual current detecting devices; unless it is a Residual Current Breaker with Overcurrent protection (RCBO), Residual Current Circuit Breakers (RCCBs) do not provide overcurrent protection; an RCCB carries two ratings, the tripping current in milliamps and the current-carrying capacity, and additional protection against overload is required. Also read in the same collection: TT earthing systems and earth-fault current, and Type AC RCDs being suitable only for sinusoidal residual current.
Checked 5 November 2026 · Used for the terminology only: RCD as the generic term, RCCB as residual-current protection without integral overcurrent protection, and RCBO as residual-current and overcurrent protection combined. The page's statements about overcurrent are therefore statements about an RCCB, and the app does not generalise them to every device called an RCD. Its TT passage is used to show why an earth-fault current too low to operate an overcurrent device within the permitted time is a fault-protection problem rather than a shock-protection detail. Regulation numbers and figures on the page belong to BS 7671:2018 and are not reproduced.
Open source
S41
The Provision and Use of Work Equipment Regulations 1998 (SI 1998/2306), regulation 6
The National Archives (legislation.gov.uk) · In force 5 December 1998; latest available (revised) text, including textual amendments to regulation 6(5)
Regulation 6 in full. Paragraph (1): inspection where the safety of work equipment depends on the installation conditions, after installation and before first use, and after assembly at a new site. Paragraph (2): inspection at suitable intervals and after exceptional circumstances where the equipment is exposed to conditions causing deterioration liable to result in dangerous situations. Paragraph (3): the result of an inspection made under the regulation must be recorded and kept until the next inspection under the regulation is recorded. Paragraph (4): physical evidence of the last required inspection where equipment leaves the undertaking or is obtained from another person's undertaking. Paragraph (5): the equipment to which the regulation does not apply (power presses under regulations 32 to 35, guards for their tools, lifting equipment, winding apparatus under the Mines Regulations 2014, equipment under regulation 22(4) or 23(2) of the Construction (Design and Management) Regulations 2015, and equipment under regulation 12 of the Work at Height Regulations 2005).
Checked 5 November 2026 · Used for one qualification to HSE's statement that portable appliance testing records are not a legal requirement: where work equipment falls within regulation 6, paragraph (3) requires the result of an inspection made under that regulation to be recorded and kept until the next such inspection is recorded. The applicability is deliberately not generalised. The duty is on the employer, it attaches to inspections the regulation requires, and the regulation's own paragraph (5) carves equipment out — so nothing here says that every portable appliance inspection or test carries a statutory record duty. Paragraphs (1) and (2) are used only to describe when the regulation requires inspection.
Open source
S42
Inspection of work equipment
Health and Safety Executive · Web guidance, page updated 29 October 2024
Purpose of inspection; not all work equipment needs formal inspection and a quick visual check before use is often sufficient; inspection necessary where significant risks may arise from installation, reinstallation, deterioration or other circumstances, with need and frequency determined by risk assessment; the result of the inspection should be recorded and kept at least until the next inspection of that equipment; records need not be in writing but must be held securely and made available to an enforcing authority; records are not normally required for the simplest pre-use checks; equipment should not be used unless the required inspection is known to have taken place; physical evidence of the last inspection where equipment leaves the undertaking or comes from another.
Checked 5 November 2026 · Used to read PUWER regulation 6 in its operational context (S41): inspection is risk-based, not every item needs formal inspection, and where a record is required it is kept at least until the next inspection and need not be in writing. Used only for that context and for the limits it puts on the record duty; it supplies no interval, no test method and no acceptance value.
Open source
S43
Electrical Installation Guide — Harmonic distortion indicators: power factor
Schneider Electric (electrical-installation.org) · Online edition, page last edited 5 August 2026
Power factor λ as the ratio of active power P in kW to apparent power S in kVA; the warning that power factor must not be confused with displacement power factor cos φ, which relates to fundamental signals only; apparent power calculated from r.m.s. values, so power factor integrates voltage and current distortion; where voltage is sinusoidal or virtually sinusoidal, active power is a function of the fundamental current, P ≈ U1 I1 cos φ, giving λ ≈ cos φ ÷ √(1 + THDi²).
Checked 5 November 2026 · Used for one distinction: cos φ is the displacement power factor and describes the fundamental signals, while the power factor λ = P/S also accounts for distortion, so P = V × I × cos φ holds as a statement about real power only where the voltage and current are sinusoidal. Used to qualify the app's power statements and to keep the arithmetic it teaches inside its assumptions. No harmonic calculation, correction method or equipment design guidance is taken from it.
Open source

What this app does not replace

Practical training and hands-on supervision.
Current reference publications — every acceptance value this app states is attributed to the source that gives it, and none of them replaces the Code of Practice's own tables or a manufacturer's instructions.
Manufacturer instructions for the equipment you are working on.
The judgement of a competent person.

The practice mock

The mock is forty questions drawn from a curated bank of one hundred source-checked questions. The mix across the seven knowledge outcomes follows the qualification handbook's published question weighting, scaled from fifty questions to forty, so the balance is fixed while the individual questions change between attempts.

It is a practice format and nothing more: no time limit is applied, no pass mark is set, no pass or fail result is shown, and a score here is not a predicted result. Questions are selected for criterion coverage, not for difficulty calibration; unreviewed demonstration questions and near-duplicates are excluded from the bank.

Each submitted attempt is saved on this device with its questions, answers, flags and score. Attempts saved before the forty-question format are kept as they were, labelled with the ten-question format they used.

Appearance

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Contact

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PAT Pass · content set 0.1.0-demo · source-checked draft material, not technically approved