The City and Guilds 2391-10 has no formal candidate entry requirements, however,
it is really intended for experienced people who may already be working in the electrical
industry or who already hold the 2392. The 2391 is not aimed at non-qualified electricians
or those who do not have relevant experience in inspection and testing. Candidates
without the relevant experience and/or qualifications should consider the 2392-10
qualification first, which is the Level 2 Certificate in Fundamental Inspection,
Testing and Initial Verification. They should also try to obtain industry experience
Candidates wishing to take the 2391-10 qualification would be strongly advised to
obtain the 17th Edition first, which demonstrates a knowledge and understanding of
the 17th Edition IET Wiring Regulations (BS7671).
Tips on Passing your 2391 Exam - Level 3 Certificate in Inspection, Testing and Certification
of Electrical Installations
The 2391 qualification is intended to enable the candidate to develop the necessary
understanding and technical knowledge relating to the inspection, testing and certification
of electrical installations.
About the 2391 Exam
To obtain the 2391 qualification, candidates are required to complete one written
and one practical assessment.
We'll deal here with Unit 301 which is the written examination.
The written (or theory) part of the 2391 exam comprises of two sections, Section
A and Section B and a total time limit of 2.5 hours applies.
Section A consists of 20 short questions which are worth a total of 60 marks (3 marks
each). Each question may be divided up into three parts (a,b and c), with each part
being worth 1 mark. Some questions may be divided into 2 parts. In this case, one
part of the question will be worth 1 mark and the other part 2 marks.
As can be seen from the chart, Section A is made up of questions from three key subject
* Preparation for inspection and testing (3 questions)
* The inspection process (2 questions)
* Testing (15 questions)
In Section A you will generally encounter questions relating to Health and Safety
and both statutory and non statutory documents relevant to inspection and testing.
You will also likely encounter questions relating to performing certain tests and
specifically, how to carry out the test and the correct order that the test should
be carried out.
You will need to know what expected readings are and how to verify results (adjusting
BS7671 max values by rule of thumb before comparison to measured values, etc) You
will also need knowledge of the individual test instruments (answering “a multi function
tester” will get you no points).
You will need to know what documentation needs to be completed by the tester for
different types of work.
Some of these questions will be relatively easy but some will be worded in such a
way that may make them difficult and obscure. It would appear that whoever sets the
questions opens Guidance Notes 3 at a random page and sets a question on a sentence
that first jumps out at him. It is therefore imperative that you read Guidance Note
3 as much as you can. No one passes 2391 without revising.
It is vastly important that you use the correct terminology as people loose a lot
of marks by using terms such as:
Electricity at Work Act, Health and Safety at Work Regulations, Minor Works Certificate,
All of the above would get you no points as they are not the correct terminology.
The biggest mistake people seem to make is to spend too much time in Part A. The
best advice may be to read these questions and if you know the answer fine but DO
NOT dwell on the ones you’re not sure about, miss them out and come back to them
Section B consists of 6 structured, long-answer questions.
A lot of marks can be gained or lost on this section. As can be seen from the chart,
each of these 6 questions is worth 10% of the overall marks so if you run out of
time and miss one out it could be very costly!
You will be generally be given a scenario which will give details of an electrical
installation including the type of supply and earthing arrangements. There will usually
be around 15 lines for you to read and there may also be charts or tables giving
information on the circuits used.
You will be asked about the tests/inspections required and how you would carry them
out. There may be calculations where you need to find Pfc, Zs, Insulation Resistance
values with circuits tested in parallel etc. All the information needed for the calculations
will be given.
You may also be asked to make fully labelled drawings of earth loop impedance paths
for different supply systems.
It is important to make sure that you have fully understood the question and wise
to go back and read the scenario again. The chief examiners report suggests that
students are giving answers which are relevant to 2391 but not answering the question
which has been set. This may result in no points being awarded for that answer. You
do not get extra points for waffling or providing general information, be to the
point and make sure your answer is correct to the question.
Many students find the last 6 questions are easier than the previous 20 short ones.
The problem is being able to transfer the knowledge from your head onto the paper.
Never assume that the examiner will “know what I mean” as you will only gain marks
if you can clearly demonstrate, by your answers, that you are competent in the theory
of the 2391.
Important 2391 Tips:
* Take into account the number of marks available for each question
(A question which carries 1 mark will require a much simpler answer than one carrying
* Answer the question
This may seem obvious, but many students fail due to misunderstanding what is being
asked and what is required. Read the question carefully and provide the correct response.
* Note the wording of the questions and structure your answer accordingly.
The question may contain words such as: STATE, LIST, EXPLAIN WITH THE AID OF A DIAGRAM,
EXPLAIN BRIEFLY, SHOW ALL CALCULATIONS etc. You should bear this in mind when answering.
For example, EXPLAIN BRIEFLY would require a brief explanation, usually no more than
one or two sentences, STATE may be a short statement and may even be only a few words
or less. Others such as SHOW ALL CALCULATIONS are self explanatory, but a correct
answer without showing the calculations would only gain a small percentage of the
actual marks available for that question.
* Use the correct terminology
Apply the terms used in BS7671 such as'circuit ptotective conductors', 'main protective
bonding' etc. Using general terms such as 'earthwires' or 'cross bonding' will not
gain you any marks.