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WorksheetsFault finding Jan 25 (challenging)
Total questions: 34
Worksheet time: 17mins
The HSE Guidance Note GS 38 gives advice and guidance on
The electricity at work act
Test equipment/probes used by electricians
Dead testing
Use of Guidance note 3
Select the first step to be taken when carrying out a safe isolation
Prove the test meter
Lock off the device
Identify the circuit to be worked on
Put the key in your pocket
Which scenario will have no implications to other personnel, customers or clients when electrical circuits are isolated to allow work to be carried out safely?
Turn the power off in a busy office
Turn the supply to a lighting circuit off in a toilet with no windows
Turn the supply of to a data room
Isolating the power supply to a metal working machine after employees have gone home for the evening
The electrician has mistakenly isolated the circuit breaker supplying the upstairs sockets.
What are the potential safety implications to the electrician
No one knows the electrician is there
The lights will be out
The electrician may receive an electric shock
He will never find the fault its the wrong circuit
What size fuse is usually fitted in test lamps
50mA
500mA
0.05A
5A
An observation recorded on an Electrical Installation Condition Report has been given a classification code of 'C1'.
What does the classification code of 'C1' signify
Improvement recommended
Doesn't comply with current regulations
Its in good condition, no issues
Urgent remedial action is required
A faulty light switch is replaced in a house.
The electrician notices the 45 amp cooker outlet is cracked and replaces it
What documentation should be completed.
2 Minor works certificates
2 Electrical installation Certificates
Electrical condition report
Energy efficiancy report
During fault diagnosis, an electrician has found a dangerous situation that could result in injury.
Why is it important for the electrician to provide the client with detailed information on the situation in a clear, courteous and accurate manner?
So the customer is aware of what components are faulty
So the client is aware of the danger and the urgency of any remedial action
So the electrician is seen to be professional
The electrician could end up making more money
The instrument used to determine the ability of a protective device such as a fuse to function after a fault is
An approved continuity tester
A PFC tester
An insulation resistance tester
An EFLI tester
A fault has been reported on a piece of equipment. To assist with fault location, why is it worthwhile checking previous maintenance records?
They will explain how the equipment works
They may include up to date circuit diagrams
They will identify how often the equipment is maintained
They may identify a similar fault or gradual deterioration.
For fault diagnosis, collection and analysis of data may involve
Contacting the council
Contacting the Health and Safety Executive
Talking to users
Contacting building control
Which dangerous gas is emitted from lead acid cells?
Helium
Nitrogen
Oxygen
Hydrogen
When carrying out insulation resistance testing, to prevent damage to equipment the tester must ensure that
All incandescent bulbs must be removed
All electronic equipment is disconnected
All motor isolators are turned off
All heating elements are turned off
A circuit breaker in a consumer unit keeps tripping. An electrician carries out an insulation resistance test between live and earth and gets a reading of 3Ω. What is the likely cause of the circuit breaker tripping?
Live conductor connected to earth
Overload
Open circuit
Circuit breaker rating too low
The neutral wire on a socket outlet has become disconnected from its termination. This fault would be detected as
A high resistance joint
An open circuit
A short circuit
Insulation resistance failure
A new 3 phase and neutral distribution board has been installed. Before powering up the boards, tests are carried out and a line to earth short circuit is found at the board. Which of these is a possible cause of the fault.
Two of the phase conductors have been reversed
A line conductor, and cpc conductor have been connected to the same point
The neutral has not been connected to earth
There is an open circuit on one of the phase conductors
An inspection schedule shows that five years ago, the insulation resistance between live conductors and the cpc of a 400V welder connection point was 120MΩ. Now the reading is 50kΩ. A possible cause is
The cpc conductor is broken
A faulty RCD
An open circuit
Cable insulation damage
A socket outlet is damaged and badly discoloured. What is the likely cause?
High resistance connection
Fault switch
Incorrect size fuse fitted
Short circuit
The setting of the overload is calibrated in
Coulombs
Amps
Bolts
Ohms
When a vacuum cleaner is plugged into a particular socket it intermittently stops working. What is the most likely cause?
A loose cable in the socket
The motor has burnt out
A broken wire in the plug
The plug contains the wrong size fuse
A faulty socket is replaced in a bedroom. Which document should be issued to the person ordering the work?
Electrical installation certificate
Minor electrical installation works certificate
Electrical installation condition report
Schedule of testing
An engineer has just completed an Electrical Installation Condition Report. What action should the engineer now take?
The engineer should keep the original report, and send a copy to the National Inspection Council
The person ordering the report should be given the original report, and the engineer should keep a duplicate copy
The owner of the installation should be given the original report, with a copy going to the Local Authority, and the person who requested the report, if this is not the owner.
The Local Authority should be sent the original report, and a copy given to the person who ordered the report.
An electrician is working in a small high street shop and explains to the owner that it is necessary to isolate the electrical supply. In order to safeguard his customers what should the owner do?
Install temporary lighting
Close the shop until power is restored
Have staff escort any customers round the shop
Only allow a limited number of customers into the shop
An electrician working on a fault machine’s control panel in a large factory finds a fuse which has blown, and there are no spares for that size.
Fit the nearest larger fuse size
Report this to the stores
Fit the nearest smaller fuse size
Report to the maintenance supervisor for advice
When fault finding, which of the following apply to customer relations?
The electrician needs to be flexible and sensitive regarding when supply can be isolated
The electrician needs to be discourteous if they encounter a customer
The electrician does not have to worry about the impact of noise
The electrician does not have to worry about any damage incurred.
If an electrician informs a client of the need to isolate the supply:
There is no need for any more control measures
There is no further health and safety obligation required
It will remind the client of the importance of turning the supply back on
The implication and timing when supply is turned off can be discussed.
Isolating a power supply includes:
Switching off secondary supplies only
Switching off primary supplies only
Discharging only stored energy
Isolating and discharging all forms of energy.
High resistance joints (terminations) are associated with:
Unsheathed cables
Loose connection
Over-tightened connection
Damaged conductor.
Discovering copper cable that has been terminated with an aluminium crimp will require the cable to be re-terminated or replaced. This is because of:
Dissimilar metal corrosion
Protective device will operate
Volt drop issues
Termination contact resistance will be low
One of the dangers of electricity in relation to testing and fault finding is that:
The supply may need to be dead
The supply may need to be live
Manufacturing may be affected
Heavy fines are possible
Following replacement of a faulty piece of equipment, completion of this particular task would include:
Full functional test
Completion of job sheet
Replace any protective devices that operated
Full set of dead tests.
Excessive volt drop means that the voltage at the supply end:
Is less than voltage at the consumer load
Is more than the voltage at the consumer load
Is the same as the voltage at the consumer load
Is double the voltage at the consumer load
Which of the following is a major consideration of making good?
Colour
Cost
Non-flammable material
Soundproof
Which gas is produced as a by product of charging particularly a lead acid battery
Calor Gas
Butane Gas
permeable gas
Hydrogen gas
