Re-take - Useful Information for 2394 :

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Means of earthing :
The means of earthing is the arrangement through which a connection is made to the general mass of Earth .

 

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On small rant mode . Chief Examiner's report

Examples Only , Scenarios

• Additional lighting point (luminaire and/or switching) on a single existing circuit.
- Minor Works Certificate may be used provided the existing circuit protective device is suitable for protection of the modified circuit, and other safety provisions are adequate

Changes to existing electrical installations, such as Additions or Alterations . your Q . Overlooked
Existing circuit protective device is suitable for protection of the modified circuit .. make a statement

Chief Examiner's report , 2394 , lost marks
• Additional socket-outlet on a single existing radial or ring circuit
- Minor Works Certificate may be used provided the existing circuit protective device is suitable for protection of the modified circuit, and other safety provisions are adequate

• Replacement of an accessory, such as a socket-outlet or a ceiling rose, on a like-for-like basis

Changes to existing electrical installations, such as additions or alterations

( MEIWC ) Part 2 Installation details .
( 3 ) Protective devices for the modified circuit ... ( Type ........ Rating ....... A ) ◄◄◄ ( Protective devices )

Examples of work that falls within the scope of a Minor Electrical Installation Works Certificate . R/P.394

• the addition of a socket-outlet to a ring or radial final circuit
• work carried out on a lighting final circuit, including an alteration to the switching arrangements
• the addition of a lighting point or
• the replacement of an accessory or luminaire

work considered to fall within the scope of the Minor Electrical Installation Works Certificate, refer to the Minor Electrical Installation Works Certificate.

Note : that for the provision of a new circuit, the Electrical Installation Certificate must be used; Not the Minor Electrical Installation Works Certificate.

R/P. 196 , Any defects or omissions in the work covered by the Electrical Installation Certificate or the Minor Electrical Installation Works Certificate must be made good before the Certificate is issued ( Regulation 632.4 ) and before the installation is energised.

Minor Electrical Installation Works Certificate may be used only
where the work involves an alteration or an addition to an existing single circuit and where the work does not entail the provision of a new circuit .

Verification of the means of earthing
the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate ’.

 

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How hard can it BE ??? 2394 / 5 .

Unit 301 - Multiple choice examination . 2013 / 14 .

This examination covers areas of knowledge & understanding which are common to both ( Initial verification ) & ( Periodic inspection )
This assessment is the same assessment for both qualifications & learners need only achieve the test once .

40 questions & 1 hour 20 minutes long ... Closed book examination

Outcome:
Understand the requirements for completing the safe isolation of electrical circuits & installation(s) .. N/questions ( 7 ) (%) - 18
Understand the requirements for inspection & testing of electrical installation(s) .. N/questions ( 2 ) (%) - 5
Understand the requirements for safe testing electrical installation(s) .. N/questions ( 11 ) (%) - 27
Understand the requirements for testing circuits which are not energised .. N/questions ( 7 ) (%) - 18
Understand the requirements for testing energised installation(s) .. N/questions ( 13 ) (%) - 32
Total .. N/questions ( 40 ) (%) - 100

Unit 302 - Written Examination
The examination papers for both qualifications ( 2394 & 2395 ) have the same format , They each have ( 6 structured ) qualifications & are 1 hour 30 minutes long . Each question is worth 15 marks .

 

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Your Q .

Structure of the exam .
Each paper is divided into two sections , Section A & Section B .

Section A of each paper has three-questions which are often divided into a number of parts ( a , c , & i ) ii) , iii ) & so on
with each part of the question relating to a different learning outcome , The number of marks available for each part of the question is shown on the paper & this can be used to indicate how long to spend on your answer .

Section B also has three questions, but these relate to the scenario contained within a " source " document . These questions may also be divided into parts but often relate to a single learning outcome . Candidates are expected to display an in-depth knowledge of the particular subject .

Note : 2394
►► Typical examples include ( DESCRIBING a TEST PROCRDURE ) or ( EVALUTING TEST RESULTS )

As the Chief Examiner , reminds us .

Knowledge of BS-7671
Guidance Note 3 &
Electricity at Work Regulations GS-38 is required by all candidates. Some candidates demonstrate little background knowledge and struggled with questions relating to the requirements of GS 38, the purpose of Initial Verification, the steps to take should a test fail and what the test button on an RCD does.

Chief Examiner (13) 2394: Chaps this is not a spin Off . from 2392/10 .. PS no written Exams .

The Chief Examiner is asking you . TO
Read carefully & answer what the ( Question actually Asks )

Often a question is answered ( INCORRECTLY ) because of a ( failure to UNDERSTAND ) what is being asked & what is required , it is an easy trap to fall into under exams conditions where you are under pressure .

Chief Examiner Report . is for a reason . Learn by our mistakes'

The danger here is that you may answer a question to which you know the answer , ( But ) which is not the question you have been asked in the paper ( 49% ) Remember , the questions are set to ( Establish your level of understanding in specific areas ) so the correct response is important if the marks are to be obtained ,

Chief Examiner Report . Learn by our mistakes'
Take a little longer to READ the QUESTION carefully to ensure you are quite clear about what is required .

 

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Where am I going Wrong !!

Chief Examiner : 2394 : Wording of Questions :

I will not download this again , ◄► Take heed

Coupled with the number o marks available . gives valuable clues as to what is expected , the words used in the question provide the first clue . if you look out for the following words & phrases & understand what they mean , you should be able to provide an appropriate answer .

Meanings : C&Gs

State :
The means the answer is expected to be a short statement , not a long or ( RAMBLING PARAGRAPH ) The response to this type of question may even be just a single word or group of words which may not be need to be a complete sentence .

List :
This means you should produce a simple list of items or actions , The answer should be similar to that produced for the " State " question , however ,
on this occasion the items would be expected to follow a sequence & form a list , as would be expected for a shopping trip .

Explain briefly :
This requires a brief explanation ; usually no more that one or two sentences . it does not require paragraphs of explanation & the word " briefly " is used to indicate this requirement .

Explain with the aid of a diagram :
This means exactly what is says . The answer should comprise both a diagram & an explanation , The examiner is trying to help you achieve maximum marks by asking for both an explanation & a diagram because this method of providing information is likely to be the most efficient .

Show all calculations :
Again the examiner is tying to help you score as many marks as possible, Where a calculation is required & the only thing offered by the candidate is the numerical answer , then if it is wrong , the candidate would score no marks . if the candidate includes each step of the calculation then marks will be awarded for each correct step . it is always in your best interest to show all stages of the process , Where relevant remember to show the applicable units which apply to your answer e.g. ( V , Ω , kA ) etc .

With the aid of a fully labelled diagram :
This indicates that a diagram needs to be provided with the component parts clearly labelled , The marks for these questions are divided between the diagram & the labelling .

To obtain the maximum marks for the question both the labelling & the diagram must be completed

Describe :
These questions often relate to test procedures & you are required to demonstrate your knowledge of the test process , look at the number of marks available to give you an indication of how much detail you need to go into .

Describe , in detail :
This indicates that a more detailed answer is required & again the number of marks available for the question gives an indication of the depth of the answer required

A series of short bullet pointed statements is a very effective method of providing an answer , but remember that all necessary information must be included

Direct measurement :
This indicates that a test is required & the results are not to be established by using a calculation . For example , where you are asked to describe the direct measurement of earth-fault-loop-impedance , ◄► Take heed
then a description of the test procedure is required , Describing an ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) test & then stating how to determine the value by calculation using , Zs = Ze + ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) will result in no marks being awarded for the answer .

 

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Terminology : ( When things go Pear Shape )

The simplest of mistakes will cost you . " marks "

it is important to answer questions using the correct terminology , which is the same as that used in GN-3 & BS-7671:2011:

Chief Examiner has given you a reasonable explanation . ( Why ) Always use correct titles & terminology .
Brand names should ( Not ) be used to describe items of equipment . test instruments & the like .

Chief Examiner , example
the instrument used to test for continuity is a low résistance ohmmeter . it should not be referred to using a manufactures name ( Megger ) or referred to as a continuity tester .

This is because the precise performance requirements given in BS-7671: & GN-3 must be Met . ◄◄

Some continuity testers & instruments that provide continuity features may not meet these requirements.

Your Q . ▼ Here's you reason .
Multifunction test instruments are commonly used for testing electrical installations . You need to be aware of the individual functions & ranges of these instruments , This includes such functions as insulation résistance , continuity , earth fault loop impedance & prospective fault current measurement .

The appropriate measurement scale for a particular test must be clearly stated , Also be careful to use the correct units & symbols to describe test instrument readings , ( mΩ , Ω , MΩ , A , kA , mS )

The use of the correct terminology for the component parts of an electrical system is also important .
The application of the terms used in BS-7671: is necessary as this leaves no doubt as to the part being described . typical terms , includes earthing-condutor , main-protective-bonding-conductors & circuit-protective-conductors , Terms such as ( earth wires or cross-bonding ) do not correctly identify components & the examiner is unable to award marks for such items .

Another common error is the use of incorrect titles for documents , if you refer to the " Electricity at Work Act " instead of the " Electricity at Work Regulations " or the Health & Safety at Work Regulation's instead of the " Health & Safety at Work Act " this will result in no marks being awarded. this also applies to the title of documents which are completed during the inspection & testing process & handed to the client .

 

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Section ( B )
Each paper is related to a scenario which is given in the Source Document .

The scenario gives details of an electrical installation , or part of an installation . it identifies what is to be carried out , & provides information that is to be used to answer the final three questions on the exam paper . This means that the answer to these questions should relate to the installation indentified in the scenario .

The most common error made by candidates at this point in the paper is failing to ( READ ) the scenario & apply the information given to these final three questions .

scenario , clearly states a TN-C-S system is used & a question asks for a diagram of the earth fault loop path , producing a drawing of a TN-S system will result in no marks being awarded . Etc

Common errors : when answering questions that relate to the scenario .
- not obtaining permission for isolation or for testing to proceed .
- no isolation procedure mentioned when it is appropriate
- no instrument & lead check carried out
- incorrect procedures described , such as not being able to describe the three steps in GN-3 for ring final circuit continuity
- not describing the test process in the correct sequence
- failure to consider the safety aspects necessary for the testing process
- failure to reinstate the installation safely once testing is complete

You are expected to be able to describe the procedures for carrying out activities , including the inspection & testing of installations & circuits , These descriptions should follow the format given in GN-3 .

 

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Written Examination 2395 . Q/As ( 1 )

(i) The electrical installation in a craft workshop is scheduled for a periodic inspection & test for insurance purposes .
a) State two statutory documents which apply to the inspection & testing process

A) Electricity at Work Regulations .
A) Health & Safety at Work ( etc ) Act .

Comments .
Abbreviations such as EWR & HSWA are acceptable . candidates must correctly identify whether these are an Act or Regulations in order to achieve the marks .

1 b) State three non-statutory documents which the inspector may need to refer to relating specifically to inspection & testing

BS-7671:
On - Site Guide
Guidance Note

Comments
GS-38 is an acceptable alternative so any three from these four are acceptable . Abbreviations such as OSG. & GN-3 are also acceptable answers . As the question asks for three items , the examiner will only mark the first three responses .

1 c) State who the inspector will consult to establish the extent & limitations of the periodic inspection & test
A) The client
A) The insurance company
Comments The person ordering the work or the person requesting the work are acceptable alternatives to the client . note Read the question carefully , the main question stem specifies that the work is for insurance purposes.

The response must relate to the insurance company & so other interested third parties or any other specific third party such as licensing authority etc will not receive a mark .

1 d ) Explain why the sequence of testing for the periodic inspection may be diffident to that given in BS-7671: for initial verification
A ) The installation has been inspected & tested & placed in service . Periodic inspection verifies the current condition or the safety of the installation 7 not the confirmation of the safety of the installation before placing in service

Comments
The candidate needs to explain the purpose of periodic inspection & how this differs from initial verification in order to obtain the marks, Examiners will consider the description used & whether this explains the reason for there being no sequence for the periodic tests . Answers such as inconvenience & because the installation is energised are not acceptable as these do not affect the sequence of testing but relate to the extent & limitations agreed with the client .

Tip . Many candidates confuse the sequence of tests with the sampling of the installation , sampling does not relate to the sequence , BS-7671: gives a required sequence of tests to be carried out at initial verification , All these tests could be carried out at periodic inspection but not necessarily in the same sequence . The answer needs to clarify why this is the case .

Chief Examiner had a field day with this ONE .

1 e ) State the first action to be taken by the inspector should an exposed live part be identified on a socket outlet circuit during the inspection
A ) Make a recommendation to the responsible person that the circuit is isolated until a repair can be carried out .

Comments
A ) Alternative answers include ;
inform client & obtain permission to isolate until repair can be carried out
Or
Isolate with the clients permission until a repair can be carried out .

Notes :
Isolate the supply & record the results , & similar answers are not acceptable as the inspector is required to inform 7 recommend the isolation . Not to carry out the isolation without first seeking agreement from the Client / User .

Guidance Note 3 , in the general requirements section , identifies the action to be " recommend the immediate isolation of the defective part "
The person ordering the work should be informed , in writing , of this recommendation without delay ,

 

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2 a ) A periodic inspection is to be taken in a hotel fitness room .
i) State three checks that need to be carried out to avoid damage to equipment before an insulation résistance test is conducted .

Comments :
Alternative answers include ; ensure no connection between live conductors & earth or link out controls .

As the question asks for three items , the examiner will only mark the first three responses .

2 a) ii) State the test voltages to be applied for the insulation résistance test

A) 500V
2 a) iii ) State the effects on the value of insulation résistance produced by cable length .

A ) As length increases resistance decreases

Comments :
An alternative answer includes as length decreases résistance increases .
Alternative terms such as higher or lower are acceptable

2 b) Insulation résistance tests between live conductors & earth on the individual circuits produced the following results , 200MΩ , 200MΩ , 150MΩ , 50MΩ , 25MΩ , 100MΩ , 2MΩ .

Calculate the expected overall value of insulation résistance if the installation was tested with ( with all the circuit connected )

Show all calculations .
A)

1/Rt = 1/R1 + 1/R2 + 1/R3 + 1/R4 + 1/R5 + 1/R6 + 1/R7

1/RT = 1/200 + 1/200 + 1/150 + 1/50 + 1/25 + 1/100 + 1/2

1/RT = 0.005 + 0.005 + 0.007 + 0.02 + 0.04 + 0.01 + 0.5

1/RT = 0.587

RT = 1.7MΩ

Comments :
Either the formula or the figures are acceptable for the first line . The correct units must be included in the final answer to obtain the marks .

Tip : it is important to show all the calculations' used to arrive at the answer as should an error be made the marks lost will relate just to the error whereas providing just the answer or omitting some calculation stages together with obtaining the wrong answer will result in all the marks being lost .

2 b ) ii) State , given reasons , whether the insulation résistance for the installation complies with BS-7671:
A ) 1.7MΩ ≥ than minimum 1MΩ & so it complies .

Comments :
Candidates need to explain the reason for their answer so simply " yes " would only receive 1 mark .

The response to Part (ii) of this question is dependent on the answer to the candidates response to Part (i) if the candidate has an incorrect answer in (i) this will not affect the marks awarded in (ii) The examiner will mark (ii) based upon the answer given by the candidate in (i)

 

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2394 : Inspection & Testing : Q/As . your turn , your call .

A test of continuity of the ring final circuit supplying the stages area socket-outlets is to be carried out .

i) State the test instrument to be used for the test .
ii) State ONE check to be made on the test instrument before carrying out the test other than calibration
iii) State the action to be taken with the test leads before the test is carried out . Remember this one .

 

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Inspection & Testing : Q/As .

C&Gs has put you on the Spot Here . You have to deal with it .

Q ) Describe how the continuity of ring final circuit test is to be carried out on Circuit 9 once the circuit has been safely isolated & secured ( 9 mark )
Q) State whether the earthing conductor is either connected or disconnected when carrying out tests to establish the prospective fault current .
Q ) Describe how a test is carried out to determine the prospective fault current at the origin of the installation by direct measurement ( 10 mark )
Q ) Explain how the inspector confirms that the installation complies with the requirements for prospective fault current protection

 

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Q ) Describe how the continuity of ring final circuit test is to be carried out on Circuit 9 once the circuit has been safely isolated & secured
A) Connected .
Comments .
As the Q asks whether the earthing conductor is connected or disconnected a single word answer is all that is necessary .

Q) State whether the earthing conductor is either connected or disconnected when carrying out tests to establish the prospective fault current
A)
- Secure the area around distribution board
- Access incoming live terminals
- Using a PFC tester ( or EFLI tester set to kA )
- Confirm test leads comply with GS-38
- Connect to incoming supply side Line and Earth
- Measure PSCC
- Record highest result as the PFC
- Reinstate the D/B .. Distribution board

Comments
in this case there have been no previous questions relating to the preparation such as type of instrument etc . and so this information needs to be included in the answer .

Failure to identify that the test leads must comply with GS-38 will lose seveal marks , it is vital to remember that the earthing and all protective bonding conductors are connected whilst this test is carried out .

 

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Mistake sorry about that . Windows 8 ▲▲▲▲ Discard Q/As .......................... ▲▲▲▲ Start again


Q ) Describe how a test is carried out to determine the prospective fault current at the origin of the installation by direct measurement

A)
- Secure the area around distribution board
- Access incoming live terminals
- Using a PFC tester ( or EFLI tester set to kA )
- Confirm test leads comply with GS-38
- Connect to incoming supply side Line and Earth
- Measure PSCC
- Record highest result as the PFC
- Reinstate the D/B .. Distribution board

Comments
in this case there have been no previous questions relating to the preparation such as type of instrument etc . and so this information needs to be included in the answer .

Failure to identify that the test leads must comply with GS-38 will lose several marks , it is vital to remember that the earthing and all protective bonding conductors are connected whilst this test is carried out .

 

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Q) State whether the earthing conductor is either connected or disconnected when carrying out tests to establish the prospective fault current .

A) Connected

Comments
As the Q asks whether the earthing conductor is connected or disconnected a single word answer is all that is necessary .

 

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GN-3 . P/54 . Instrument , Use the prospective fault current range of a suitable earth fault loop impedance tester for this test . 4.5 final paragraph

Using a PFC tester ( or EFLI tester set to kA )

GN-3 . Earth Fault Loop Impedance testers ; BS-EN-61557-3 .. Younger members

2394 : Q to A , These instrument operate by circulating a current from the Line-conductor into the protective earth . This will raise the potential of the protective earth system .

Q ) To minimise electric shock hazard from the potential of the protective conductor , the test duration should be within safe limits ????
PS , what is your safe limits .. C&Gs

4.5 Earth fault loop impedance
A) This means that the instrument should cut off the test current after 40mS .. refer to