2391 Exam Questions !

[Zenn]

Zenn you have approached this forum in the correct manner. Well done sir.

When you post up these questions please have a go at answering them and let us correct you when your wrong. We are happy to help but we are not here to do your homework.

Zenn you've got our attention so don't waist it.

I am really happy to hear this man, I'm off from work next week for 10 days just for this exam lol. Ill try to answer them tomorrow when i got back from my work.

 

[sam80]

I'm doing the test the same day mate. Why did you say it your last time ??
Thanks Sam

 

[Zenn]

because they changed it to 2394 and 2395 and also I have failed twice before. do you want to go through the exam paper that I have posted and check our answers ? I can post section A as well on here.

 

[Zenn]

December 2011

Section (A)

1. The inspection of an electrical installation is being undertaken as part of the initial verification. state three conditions which must be verified, as far as is reasonably practical, during this inspection.

Answer :From Chapter 61 (Red Book)
611.2 The inspection shall be made to verify that the installed electrical equipment is:
i) in compliance with Section 511 (this may be ascertained by mark or by certification furnished by the installer or by the manufacturer), and
ii) correctly selected and erected in accordance with the regulations, and
iii) not visibly damaged or defective so as to impair safety.
_________________________________________________________________________________________________
2) State:

a) one statutory document
b) two non-statutory publications
to which the inspector may refer whilst carrying out an inspection and test of an electrical installation.

Answer:
a) Three main Statutory documents are:
The Health and safety at Work Act 1974 (HASWA)
The Electricity at Work Regulations 1989 (EAWR)
The Building Regulations Part P 2000

b) BS 7671:2008 Requirements for Electrical Installations
Guidance Note GS38 on Test Equipment
On-Site-Guide
Guidance Note 1-7
Code of Practice for in-Service testing of portable appliances.
_____________________________________________________________________________________________
3. State
a) two supply parameters which can only be obtained by enquiry to the Distribution Network Operator(DNO)
b) one supply parameter which may be obtained from either the DNO or measured by the inspector.

Answer:
a) any of this below:
The maximum Prospective short-circuit current at the supply terminals
The maximum earth loop impedance of the earth fault path outside the installation (Ze)
The type and rating of the distributors protective device or devices nearest to the supply terminals
The type of earthing system applicable to the connection
The number of phases of the supply
The frequency of the supply and the extent of the permitted variations
The voltage of the supply and the extent of the permitted variations.

b) I'm thinking of : The Earth fault loop impedance or The prospective short-circuit current.
________________________________________________________________________________________________
4. State the purpose of an initial verification process as identified in guidance note 3.

Answer :
To ensure equipment and accessories are to relevant BS or BSEN standards.
To prove compliance with BS 7671.
To ensure that the installation is not damaged so as to impair safety.
________________________________________________________________________________________________
5. State the three considerations which must be made when work is to be undertaken on or near live electrical equipment.

Answer: Correct me on this one
from EWR :
No person shall be engaged in any work activity on or so near a live conductor(other than one suitable covered with an insulating material so as to prevent danger) that danger may arise unless:
a) it is unreasonable in all circumstances for the system to be dead,
b) it is reasonable in all circumstances for the person to be at work on or near it whiles it is live; and
c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.

for live working to take place, each of the terms listed above must be complied with. In effect, a clear risk assessment must be made regarding the safety of any live working.
_______________________________________________________________________________________________________________
6. State for each of the following which instrument will have been used when the measured result is
a: 28 (ms)
b) 2.5 (kA)
c) 120 (ohm)Answer:
a) RCD tester
b) Prospective fault current tester
c)Earth electrode resistance tester
______________________________________________________________________________________________________________
7. List, in the correct sequence, the first three tests to be carried out on a newly installed ring final circuit.

Answer:
i) Continuity of ring final circuit conductors
ii) insulation resistance
iii) Polarity
______________________________________________________________________________________________________________
8. The resistance of a length of single conductor is 0.8 (ohm). Calculate the resistance of this conductor in ohm when the
a) length is doubled
b) length and csa are both halved
c) csa is doubled

Answer:
a) Double
b) same
c) half
_____________________________________________________________________________________________________________

 

[cossie400]

6
C- low resistance ohm meter?

7
I- continuity of cpc
ii- continuity of ring final circuit conductors
iii- insulation resistance

8
the question asks for the answer in ohms.....

 

[lauriehurman]

Beware!
I'm not an expert and I only have 2392 but I can spot a trap when I see one

The resistance figure you are given is for 20degs. You need to convert this to 70degs to take account of the 10amps.

Laurie




Easy marks this one! work out voltage drop Vd= IxLxOhms/1000 (remember resistance is in milli ohms)

Check this as a percentage of the supply voltage power 5% lights 3 % if under that no problem .

Read more: http://www.electriciansforums.net/i.../64856-2391-exam-questions.html#ixzz28C8O33Mp[/QUOTE]

 

[Zorro]

In reality you should read the OSG page 89-107, GN3 and BS7671 part 6 and appendix 6 for the model forms also the IET 2391 exam success book all the answers are within these books.

 

[loop3]

Zenn, I don't want to put you down mate, you're obviously an intelligent guy who wants change and opportunities like most of us. A word of advice, a good mate makes a good spark, a good spark makes a good tester/ designer, a... makes a good engineer. If you jump the gun, you'll have holes in your knowledge and experience. Make sure you cover it on site as well as reading the regs. There's no quick fix. Gifted you may be, but money can't buy experience. Good luck!

 

[Zorro]

Definition of competent in BS7671 A person who possesses sufficient technical knowledge, relevant practical skills and experience for the nature of the electrical work undertaken no mention of qualifications at all. I agree with loop3 totally start off as a mate/improver and get all of the above.

 

[Zenn]

Zenn, I don't want to put you down mate, you're obviously an intelligent guy who wants change and opportunities like most of us. A word of advice, a good mate makes a good spark, a good spark makes a good tester/ designer, a... makes a good engineer. If you jump the gun, you'll have holes in your knowledge and experience. Make sure you cover it on site as well as reading the regs. There's no quick fix. Gifted you may be, but money can't buy experience. Good luck!

so what is your suggestion mate? how can I find a job as an electrician?