***Useful Information for Apprentices***

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“ General Health and Safety at Work “

Question 1.1
What do the letters CDM stand for ?
A: Control of Demolition and Management Regulations
B: Control of Dangerous Materials Regulations
C: Construction (Demolition Management) Regulations
D: Construction (Design and Management Regulations ) Answer: D )
Question 1.2
Identify one method of enforcing regulations that are
available to the Health and Safety Executive:
A: Health Notice
B: Improvement Notice
C: Obstruction Notice
D: Increasing insurance premiums
Answer: B Improvement notices require action to achieve standards which meet health and safety law :
Question 1.3
What happens if a Prohibition Notice is issued by an
Inspector of the local authority or the HSE ?
A: The work in hand can be completed, but no new work started
B: The work can continue if adequate safety precautions are put in place
C: The work that is subject to the notice must cease
D: The work can continue, provided a risk assessment is carried out,
Answer: C The work covered by a prohibition notice must cease until the identified danger is removed.
Question 1.4
Health and Safety Executive Inspector can ?
A: Only visit if they have made an appointment
B: Visit at any time
C: Only visit if accompanied by the principal contractor
D: Only visit to interview the site manager
Answer: B Inspectors have a range of powers, including the right to visit premises at any time.
Question 1.5
A Prohibition Notice means:
A: When you finish the work you must not start again
B: The work must stop immediately
C: Work is to stop for that day only
D: Work may continue until the end of the day
Answer: B The work activity covered by the prohibition notice must cease, until the identified danger is removed ,
Question 1.6
In what circumstances can an HSE Improvement Notice be issued ?
A: If there is a breach of legal requirements
B: By warrant through the police
C: Only between Monday and Friday on site
Answer: A Improvement notices require action to achieve standards which meet health and safety law .
Question 1.7
What is an “Improvement Notice”?
A: A notice issued by the site principal contractor to tidy up the site
B: A notice from the client to the principal contractor to speed up the work
C: A notice issued by a Building Control Officer to deepen foundations
D: A notice issued by an HSE/local authority Inspector to enforce compliance with health
Answer: D Improvement notices require action to achieve standards which meet health and safety law .
Question 1.8
If a Health and Safety Executive Inspector issues a“ Prohibition Notice”, this means that:
A: the Site Manager can choose whether or not to ignore the notice
B: specific work activities, highlighted on the notice, must stop
C: the HSE must supervise the work covered by the notice
D: the HSE must supervise all work from then on
Answer: B Prohibition notices are intended to Stop activities which can cause serious injury.
Question 1.9
Which one of the following items of information will you find on the Approved Health and Safety Law poster?
A: Details of emergency escape routes
B: The location of the local HSE office
C: The location of all fire extinguishers
D: The identity of the first aiders
Answer: B The poster also lists the persons with health and safety responsibilities, but not first aiders.
Question 1.10
Who is responsible for signing a Company Safety Policy ?
A: Site Manager
B: Company Safety Officer
C: Company Secretary
D: Managing Director
Answer: D The Health and Safety at Work Act requires the most senior member of management to sign the health and safety policy
statement.

Question 1.11
Which one of the following must be in a company’s written Health and Safety Policy:
A: Aims and objectives of the company
B: Organisation and arrangements in force for carrying out the health and safety policy
C: Name of the Health and Safety Adviser
D: Company Director’s home address
Answer: B This requirement appears in the Health and Safety at Work Act.
Question 1.12
Employers have to produce a written Health and Safety Policy statement when:
A: A contract commences
B: They employ five people or more
C: The safety representative requests it
D: The HSE notifies them
Answer: B This is a specific requirement of the Health and Safety at Work Act.
Question 1.13
Companies employing five or more people must have a written Health and Safety Policy because:
A: The principal contractor gives them work on site
B: The HSAWA 1974 requires it
C: The Social Security Act requires it
D: The trade unions require it
Answer: B
Question 1.14
What do the letters HSC stand for ?
A: Health and Safety Contract
B: Health and Safety Consultant
C: Health and Safety Conditions
D: Health and Safety Commission Answer: D
Question 1.15
Which ONE of the following statements is correct ? The Health and Safety Executive is:
A: a prosecuting authority
B: an enforcing authority
C: a statutory provisions authority
Answer: B The Health and Safety Executive enforces health and safety legislation.
Question 1.16
The Health and Safety at Work Act requires employers to provide what for their employees?
A: Adequate rest periods
B: Payment for work done
C: A safe place of work
D: Suitable transport to work
Answer: C This is a specific requirement of Section 2 of the Health and Safety at Work Act.
Question 1.17
The Health and Safety at Work Act 1974 and any regulations made under the Act are:
A: Not compulsory, but should be complied with if convenient
B: Advisory to companies and individuals
C: Practical advice for the employer to follow
D: Legally binding Answer: D
Question 1.18
Under the Health and Safety at Work Act 1974, which of the following have a duty to work safely?
A: Employees only
B: The general public
C: Employers only
D: All people at work
Answer: D Employers, employees and the self-employed all have a duty to work safely under the Act.
Question 1.19
What is the MAXIMUM penalty that a Higher Court, can currently impose for a breach of the Health and Safety at Work Act?
A: £20,000 fine and two years imprisonment
B: £15,000 fine and three years imprisonment
C: £1,000 fine and six months imprisonment
D: Unlimited fine and two years imprisonment
Answer: D A Lower Court can impose a fine of up to £20,000 and/or up to six months imprisonment for certain offences. The potential fine in a Higher Court, however, is unlimited and the term of imprisonment can be up to 2 years.
Question 1.20
What do the letters ACoP stand for ?
A: Accepted Code of Provisions
B: Approved Condition of Practice
C: Approved Code of Practice
D: Accepted Code of Practice
Answer: C An ACOP is a code of practice approved by the Health and Safety Commission.

Question 1.21
Where should you look for Official advice on health and safety matters?
A: A set of health and safety guidelines provided by suppliers
B: The health and safety rules as laid down by the employer
C: Guidance issued by the Health and Safety Executive
D: A professionally approved guide book on regulations
Answer: C The HSE is the UK enforcing body and its guidance can be regarded as ‘official’
Question 1.22
Regulations that govern health and safety on construction sites:
A: apply only to inexperienced workers
B: do not apply during ’out of hours’ working
C: apply only to large companies
D: are mandatory ( that is, compulsory )
Answer: D The requirements of health and safety law are mandatory, and failure to follow them can lead to prosecutions.
Question 1.23
Which of the following statements is correct ?
A: The duty for health and safety falls only on the employer
B: All employees must take reasonable care, not only to protect themselves but also their colleagues
C: Employees have no responsibility for Health and Safety on site
D: Only the client is responsible for safety on site
Answer: B The responsibility for management of Health and Safety Act at Work rests with the employer
Question 1.25
Which of the following is correct for risk assessment?
A: It is a good idea but not essential
B: Only required to be done for hazardous work
C: Must always be done
D: Only required on major jobs
Answer: C There is a legal requirement for all work to be suitably risk assessed.
Question 1.26
In the context of a risk assessment, what do you understand by the term risk?
A: An unsafe act or condition
B: Something with the potential to cause injury
C: Any work activity that can be described as dangerous
D: The likelihood that harm from a particular hazard will occur
Answer: D Hazard and risk are not the same. Risk reflects the chance of being harmed by a hazard
Question 1.27
Who would you expect to carry out a risk assessment on your working site?
A: The site planning supervisor
B: A visiting HSE Inspector
C: The construction project designer
D: A competent person
Answer: D A risk assessment must be conducted by a 'competent person’.
Question 1.28
What is a HAZARD ?
A: Where an accident is likely to happen
B: An accident waiting to happen
C: Something with the potential to cause harm
D: The likelihood of something going wrong
Answer: C Examples of hazards include: a drum of acid, breeze blocks on an elevated plank; cables running across a floor.
Question 1.29
What must be done before any work begins ?
A: Emergency plan
B: Assessment of risk
C: Soil assessment
D: Geological survey
Answer: B This is a legal requirement of the Management of Health and Safety at Work Regulations.
Question 1.30
Complete the following sentence: A risk assessment
A: is a piece of paper required by law
B: prevents accidents
C: is a means of analysing what might go wrong
D: isn’t particularly useful
Answer: C Risk assessment involves a careful review of what can cause harm and the practical measures to be taken to reduce the risk of harm.

 

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Electrical installation is defined in BS 7671 as ‘an assembly of associated electrical equipment supplied from a common origin to fulfil a specific purpose and having certain co-ordinated characteristics.’ For the purposes of Building Regulations and electrical installation means fixed electrical cables or fixed electrical equipment located on the consumer’s side of the electricity supply meter.

Extra-low voltage (ELV) is defined in BS 7671 as ‘normally not exceeding 50 V ac or 120 V ripple-free dc, whether between conductors or to earth.’

Low voltage (LV) is defined in BS 7671 as ‘normally exceeding extra-low voltage but not exceeding 1000 V ac or 1500 V dc between conductors, or 600 V ac or 900 V dc between conductors and earth.’

( Dont mix them Up )

PAT: Portable Appliance Testing: In-Service Inspection and Testing of Electrical Equipment . Synopsis :-

The Electricity at Work Regulations 1989 require any electrical system to be constructed, maintained and used in such a manner as to prevent danger. This means that inspection and testing of systems, including portable appliances, is needed in order to determine if maintenance is required.

( Remember ) ↔ Sitting the 2377-200 exam
The Order of the Questions usually follows the order of the Code of Practice, so a ► Good Tip is that Usually ► Questions that you Encounter
Early on in the Exam will be ►Relating to Information . ► you will be Asked on the -&-s Test ◄

 

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Section 712 : ( Some Small Time Reading )

Photovoltaic’s ( PV ) is the Direct Conversion of Light into Electricity. Certain materials, like Silicon, naturally release Electrons when they are Exposed to Light, and these Electrons can then be harnessed to produce an Electric Current. Several thin wafers of silicon are wired together and enclosed in a rugged protective casing or panel. PV panels produce Direct Current ( DC ) Electricity, which must be Converted to Alternating Current ( AC ) Electricity to run Standard Household Appliances. An Inverter connected to the PV panels is used to Convert the DC Electricity into AC Electricity. The amount of Electricity Produced is measured in Watts ( W ). A kilowatt ( kW ) is equal to 1.000 watts. A Megawatt ( MW ) is equal to 1.000.000 Watts or 1.000 Kilowatts. The Amount of Electricity Used over a given Period of Time is Measured in kilowatt - Hours ( KWh )

712.511 / 1 : Compliance with Standards : BS-EN61215 and :- Must be ► Class 11 ◄ Construction ( on the DC side of PV power supply system ; the Type of Insulation that is Preferable Class 11 ) ( * -&-s )

712.513 / 1 Accessibility : The Selection and Erection of Equipment shall facilitate Safe Maintenance and shall Not Adversely affect Provisions made by the Manufacturer of the PV Equipment to Enable Maintenance or Service Work to be carried Out Safely ( * -&-s )

712.53 : 712.537 : 712.537.2 ) Isolation DC / AC . Locking Off AC – 1 Isolation & Switching ◄► Locking Off DC ** – 2 Isolation & Switching ► ( Padlock ) ( * -&-s )

712.537.2.2.5 : A Switch-Disconnector ◄► shall be Provided on the DC Side of the PV Convertor ►( Warning Labels Must be Placed -&-s ) ◄ ( -&-s would like to Hear : DC Side is Still Live . when power is Cut from the AC Side ) ◄ Isolation 712.537.2 ,

712.410.3.6 : Equipment on the DC. Side shall be Considered to be Energized , even when the System is Disconnected from the AC Side ( * -&-s )

712.54 : Earthing Arrangements and Protective Conductors !! Where Protective Conductors are Installed . they shall be Parallel to and in as Close Contact as Possible with DC Cables and AC Cables and Accessories . ► -&-s would like to Hear : ( Wiring Loops in PV Systems should be kept SHORT as Possible : Reduce ( Excessive Earth Fault )

17th : -&-s . 712.537.2.2.5.1 , All Junction Boxes ( PV Generator and PV array Boxes ) SHALL carry a Warning Label Indicating that PARTS inside the Boxes May Still be Live After Isolation from the PV Convertor

AC Day Light On / Off : DC Night Light Off / On

712.412 : Protective Measure ► Double or Reinforced Insulation . Protection by the Use of Class 11 or Equivalent Insulation shall Preferably be Adopted on the DC Side .

A Must to Remember ( -&-s big time ► 712.411.3.2.1.2 Where an Electrical Installation includes a PV Power Supply System without at ►Least Simple Separation ◄ between the AC Side and the DC Side , an RCD 30mA installed to Provide Fault Protection by Automatic Disconnection of Supply shall be Type B / RCD according to ( IEC 60755 Amendment 2 ( Remember to follow the Manufacturers Intrusion’s -&-s )

Where Would I Use a Junction Box PV ? Consumer Unit ↔ Metter ↔ Inverter ↔ ( AC side / DC side ) Junction Box ↔ PV Modules Wired up to 2 / or more Modules !!!

The Risks : The particular risks associated with solar photovoltaic systems are :-

► PV systems cannot be switched off. Modules produce electricity when exposed to daylight. Hence, unlike most other electrical installation work, the installation of a PV system typically involves working on a live system. Regulation 14 of the Electricity at Work Regulations gives requirements that must be
made to ensure live terminals are either not accessible or cannot be readily touched during installation and maintenance. Such terminals will be live at all times during daylight hours. It is important that anyone opening an enclosure is aware of this.

► An electrician who has come to work on the electrical installation needs to be aware that there is a second source of energy which will also need to be isolated.

PV : RCD 30mA ( can Go Upto 300mA installed to Provide Fault Protection by Automatic Disconnection of Supply. for Bigger Ones .

 

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Electrical Safety Tests Using a Tester : ( Pat. Testing some Small Reading ) this will give you an Insight !!

Power ON / OFF press Until a Bleep is Heard the left hand and Right hand Buttons Marked Class 1 and Class 2 :
Warning : !!! Do Not Touch the Equipment being Tested while the Test is being Carried Out !!! -&-s

Q / Does the Equipment have a 3-Core Mains Lead ( Class1 ) or :- Q / 2-Core Mains Lead ( Class 11 ) ► Class1 ( Earthed ) Equipment , with 3-Core Mains Lead , ► 3 core cord set should be tested as a class 1 appliance : ◄ !!! ► 2 core cord set should be tested as a class 2 appliance : ◄
* Testing a Class 1 Appliance : ► if the Appliance Passes a Visual Inspection Proceed with the Electrical Tests : ◄ ► Connect the Earth Probe to an Exposed Metal Part on the Appliance : ► if the Appliance Under Test has an ON / OFF Switch , Make Sure it is in the On Position : ◄ Q / is the Fuse Correctly Rated for the Equipment ? ◄ -&-s
Q / If the Measured Value is Outside Acceptable Limits a Cross is Placed Next to the Earth Cont !
► a Fail is Indicated and the Test Sequence is Halted : ( This Equipment has Failed the Earth Test ) Red Label

Q / If the Measured Value is within Acceptable Limits a Tick is Placed Next the Earth Cont !
► The Equipment has Passed Earth Test ) Green Label :◄

* The Unit will Proceed with the Insulation Test :
Note : Q / The Power Switch on the Appliance Under Test Must be in the On Position to Perform an Insulation Test , ◄◄
► If the Insulation Résistance is Greater than the Acceptable Limit a Tick is Placed Next to the Insulation Enunciator and Pass
The Equipment has Passed the Insulation Test ,

* Testing a Mains Lead
Plug the Mains Lead Under Test into the IEC Socket and the Front Panel Mains Socket on the , Tester :
► You will now Test the Continuity of the Protective Earth
► If the Measured Value is Outside Acceptable Limits a Cross is Placed Next to the Earth Cont ! Enunciator ,
a Fail is Indicated and the Test Sequence is Halted ,

► if the Measured Value is within Acceptable Limits a Tick is Placed Next to Earth Cont ! Enunciator

* The Unit will Proceed with the Insulation Test ,
► if the Insulation Résistance is Lower than the Acceptable Limit a Cross is Placed next to the Insulation Enunciator and the Test Sequence is Halted : A ) ►The Cord has Failed the Test :

► if the Insulation Résistance is Greater than the Acceptable Limit a Tick is Placed Next to the Insulation enunciator
► The Cord has Passed the Test :

► The Unit will Proceed with the Wiring Test , Checking the Live & Neutral Conductors’ for ( Short or Open-Circuits or Reversed Connections )
► If the Wiring is Correct a Tick is Placed Next to the Cord enunciator and a Pass is Indicated for the Sequence

Testing a Class 11 Appliance : ► Check that the Outer Casing of the Appliance is Complete and Undamaged ◄◄ ( Inspect the Flex and Plug ) ◄◄ Note !! all Class 11 Appliances Must have a Double Square Insulation Sticker On : -&-s
* If the Appliance Passes a Visual Inspection Proceed with Electrical Tests : ► Connect the Earth Probe to the Appliance , there should be No Exposed Metal Parts , ► if the Appliance Under Test has an ON / OFF Switch , make Sure it is in the On Position ► Press the Class 2 Test Key . ► You will now Test Insulation Résistance Note !! The Power Switch On the Appliance Under Test must be in the On Position to Perform an Insulation Test . if No Appliance is Detected { will Display Following .. Operating Instructions }

 

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Q ) If Any Inspection or Test is Not Satisfactory , or you are Doubtful of the Results . ► Take the Equipment Out of Use Immediately ◄► ( Label the Equipment to Show the Reason for Failure )
► -&-s : - “ ID – No “ Means of Identifying the Appliance , Q ) Why Use “ ID Number ! A ) ►Using the ID Number you Avoid Confusing One Item with Another
► H&S – Yellow/Black , Safety Sign !! Caution , Risk of Electrical Shock , Indicates Instructions Must be Followed to Avoid Danger to Person : ► H&S - Yellow /Black , Safety Sign !! Caution , Risk of Danger , the Operating Instructions must be Adhered to in Order to Avoid Danger :
► If the Mains Socket-Wiring is Correct the Display will Show ( L/N at Tick ) ( L/E at Tick ) ( N/E at Tick ) Pass ► if The ( Live & Neutral in the Socket Wiring are Reversed or there is a Fault with the Protective Earth Connection this is Indicated by the Display ( L/N at Tick ) ( L/E . X ) ( N/E . X ) Fail ←←← FaultsIf there is a Fault with the Neutral Connection this is Indicated by the Display , ( L/N . X ) ( L/E at Tick ) ( N/E . X ) Fail ←←← Faults
* Testing an Extension Lead : ►Visually Inspect the Mains Cord and Plug for Signs of Damage : ►Check that the Correct Fuse is Fitted : ►if the Cord Passes a Visual Inspection Proceed with the Electrical Tests :
► 2.5mm2 extension leads are too large for standard 13A plugs, although they may be used with BS EN 60309 industrial plugs. Extension leads exceeding the above lengths should be fitted with a 30mA RCD manufactured to BS 7071.

 

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Remember : ( H&S – CSCS ) British Standard / European Standard / Signs ←← -&-s this will come Up

Q: What Safe Procedure Signs Should I Use ?
A: Safe procedure signs should be situated as to indicate exit routes. At least one sign should be visible from any place within the building.

Q: What are the differences between British Standard ◄ and European Standard ◄ style safe-procedure signs ?
A: British-Standard style signs have symbols and text ; European-standard styles have just ►symbols.◄ It is advised not to Mix the Two Styles .
To avoid confusion, it is advisable to have "final exit" signs at external exit points. These should have a running man symbol and text, but no arrow.

 

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H & S / CSCS :
Q ) Why is it Important to Report all Accidents ?
1 ) It Might Stop them Happening Again : ( A )
2) Some Type of Accident have to be Reported to the Heath & Safety Executive : ( A )
3 ) Details have to be Entered in the Accident Book : ( A )

( A ) 4 ) All of the Other Answers ◄ ◄ ◄ -&-s ( 4 / Q in one Answers
PS : They May come Up Like This

 

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* The maximum voltage drop allowed for a lighting circuit in a consumer[FONT=Times+New+Roman1252]’s installation, supplied by a public L.V system is[/FONT]
3% (App 12)
6%
10%
5%
* The maximum Zs for a BS EN 60898 32A B Type circuit breaker protecting a domestic ring circuit is
1.44[FONT=Times+New+Roman+Bold1253]Ω ( Table 41.3 )[/FONT]
1.5[FONT=Times+New+Roman+Bold1253]Ω [/FONT]1.2[FONT=Times+New+Roman+Bold1253]Ω[/FONT]
0.72[FONT=Times+New+Roman+Bold1253]Ω[/FONT]
* Automatic disconnection of supply is used as a method of protection for :-
Indirect contact
Basic protection
Fault protection ( Definitions )
Direct contact
* BS EN 60898 circuit breaker can be used for :-
Isolation
Emergency switching
Functional switching
All of the above ( Table 53.2 ) p/117
* Devices for protection against the risk of fire include :-
RCDs not exceeding 500mA
RCDs not exceeding 300mA ( 532.1 ) p/113
Time delay RCDs
Type B circuit breakers
* The following sources for safety services are recognised
Storage batteries
Primary cells
Generator sets independent of the normal supply
All of the above ( 351.1 ) p/41
24. The minimum insulation value when testing a FELV system is
( Table 61 )[FONT=Times+New+Roman-1-1]≥ 0.5M[FONT=Times+New+Roman1253]Ω ( test Voltage 250v – dc )[/FONT][/FONT]
[FONT=Times+New+Roman-1-1]≥ 0.75M[FONT=Times+New+Roman1253]Ω [/FONT][/FONT]
[FONT=Times+New+Roman-1-1]≥ 1M[FONT=Times+New+Roman1253]Ω[/FONT][/FONT]
[FONT=Times+New+Roman-1-1]≥ 0.25M[FONT=Times+New+Roman1253]Ω[/FONT][/FONT]
25. The maximum measured value for a BS EN 60898 16A B Type circuit breaker is
2.3[FONT=Times+New+Roman+Bold1253]Ω [/FONT]2.87[FONT=Times+New+Roman1253]Ω (41.3 & App 14 )[/FONT]
1.44[FONT=Times+New+Roman1253]Ω[/FONT]
2.19[FONT=Times+New+Roman1253]Ω[/FONT]
26. The maximum Zs to ensure 30mA RCD operation is
1667[FONT=Times+New+Roman1253]Ω ( Table 41.5 ) p/50 ( R ≤ 50V ÷ 30mA = 1667Ω )[/FONT]
500[FONT=Times+New+Roman1253]Ω[/FONT]
167[FONT=Times+New+Roman1253]Ω [/FONT]300[FONT=Times+New+Roman1253]Ω[/FONT]

Remember when your Testing RCBOs / Remove the White Tail ( Earth )

 

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CSCS : Q ) Which of these is the most Accurate way to Locate Buried Services ?
A ) Trial Holes ◄ a Must
* Cable Plans
* Architects Drawings
* Survey Drawings
Q ) if you Need to dig Near Underground Services , you should Use ?
A ) a Spade or Shovel ◄ a Must
* a Jack Hammer
* an Excavator
* a Pick and Fork
Q ) if you Need to Work in a Confined Space . One Duty of the “ Top-Man !!!! is to ?
A ) Start the Rescue Plan if Needed ◄ a Must
Q ) You are Using some Equipment . it has Just been given a PROHIBITION NOTICE . What does this Mean ?
A ) You Must NOT Use it Till it is Made SAFE !!!! ◄ a Must
Q ) The whole Site has been ISSUED with a PROHIBITION NOTICE . What does this Mean ?
A ) You must STOP Work ◄ a Must
Q ) After watching you Work , an Heath & Safety Executive Inspector Issues an IMPROVEMENT NOTICE . What does this Mean ?
A ) You are NOT Working in a SAFE WAY . ◄ a Must
Q ) a PERMIT to Work Allows ?
A ) Certain JOBS to be Carried OUT Under Controlled Conditions ◄ a Must

 

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Some old Notes
1) The balancing of single-phase loads connected across three-phase-supply systems is to :
A) Reduce the overall cable size ,
2) The purpose of the National Grid is to :
A) Transmit electricity from power stations to substations .
3) The reason for transmitting voltages at high levels is to : A) Decrease Current levels .
4) Electrical energy is transmitted over long distances by means of the National “ Super Grid “ system at a nominal voltage of : A) 400kV .
5) The common supply voltages for public “ Distribution “ in Britain are : A) 230V : 400V : 11kV :
6) The Neutral conductor of four-wire three-phase and Neutral system carries the : A) Out off balance current :
7) The relationship between Line-Current ( IL ) and phase current ( IP ) in a Three-Phase Star- connected system is given by the formula : A) ( IL =IP )
8) A Star connected system has a Line voltage of 500V, what is the Phase Voltage : A) 289V
9) The relationship between Line current ( IL ) and Phase current ( IP ) in a Three-Phase Delta connected system is given by the formula :
A) ( IL = √3 x IP )
10) A Delta connected system has a Line voltage of 500V, what is the Phase Voltage : A) 500V
11) The point at which the Neutral and Earth are connected at the supply Authorities transformer is called the : A) Star-Point .
12) Each set of windings in a three-phase power generator are set apart by : A) 120° .
13) The earth neutral of Authorities supply must be fitted at the Intake position with a : A) Solid Link .
14) The electrical energy generated by power stations is transferred to the Grid by means of : A) Transformers .
15) A typical insulator for an Overhead line Distribution system is : A) Glass .
16) Power in three-phase circuits can be calculated from which of the following formula : A) P = √3 VL IL cosØ .
17) A balanced Star-connected three-phase load is fed from a 400V, 50Hz supply . The line current is 40A, Calculate the power consumed : A) 27.7kW .
18) The nominal voltage at which heavy industry in UK takes energy from the supply companies is : A) 33kV .
19) The TT System of earthing is usually used in : A) Rural Areas .
20) When measuring the line voltage in a three-phase four-wire supply system the voltmeter should be connected :
A) Between any Two-Phase conductor’s :
21) – PME ( Protective Multiple Earthing ) is mainly associated with which of the following Earthing Systems : A) TN-C-S .
22) What protective device would normally be installed with a TT System to Offer extra protection : A) Residual Current Device .
23) A supply system which uses the sheath of a SWA cable to provide an Earth connection is : A) TN-S .
24) Three-Phase step down transformers are used in Transmission and Distribution systems to step-down from 11,000V to 400 / 230V . The form of connection on Primary and Secondary windings respectively are : A) Delta / Star .
26) The greatest source of air pollution from coal-fired power station chimneys is : A) Carbon Dioxide .
27) Electrical supply are sometimes connected in the form of a Ring because : A) This system gives better supply security than more common Radial systems .
28) in TT Earthing system the connection to Earth is Achieved by connecting to : A Metal Rod drive into the Ground .
29) Electricity is generated at an alternating frequency and time period of : 50Hz , 20mS .
30 ) Which of the following methods of generating electricity uses a fossil fuel : A) Gas Fired ,

 

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Refrigeration & Air Conditioning ( RAAC ) / CSSC

Q) If you find a coloured wire sticking out of an electrical plug , which is the correct action to take ?
A) Mark the item as defective and follow your company procedure for defective items .

Q) Extension leads in use on a site should be ? : A) Located so as to prevent a tripping hazard ,

Q) what should you do if you need additional temporary wiring for your power tools whilst working on site ?
A) Stop work until an authorized supply has been installed ,

Q) When planning a lifting operation the sequence of operations to enable a lift to be carried out safely should be confirmed in ? :
A) A method statement :

Q) The safe working load ( SWL ) of lifting equipment is ? : A) The absolute maximum safe working load :

Q) Before using a ladder you must make sure that ? : A) it is secured to prevent it from moving sideways or sliding outwards ;

Q) When positioning and erecting a stepladder , which of the following is essential for its safe use ?
A) The restraint mechanism is spread to its full extent .

Q) Generally , how may working platforms should be in use at any one time on a mobile tower ? A) One ,

Q) What is the recommended maximum height for a free-standing mobile tower ? A) in accordance with the manufacturer’s recommendations

 

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Q) What is the first thing you should do after getting on the platform of a mobile tower ? A) close the access hatch to prevent falls of personnel, tools or equipment .
Q) What should be done before a mobile tower is moved ? A) All people and equipment must be removed from the platform .
Q) What must be done first before any roof work is carried out ? A) A risk assessment must be carried out .
Q) What is edge protection designed to do ? A) Prevent the fall of people and materials .
Q) Where should Liquefied Petroleum Gas ( LPG ) cylinders be positioned when supplying an appliance in a site cabin ? A) Outside the cabin .
Q) if you are working where welding is being carried out , what should be provided to protect you from “ Welding Flash “ . A) Screens
Q) how should you position the exhaust of an engine-driven generator which has to be run inside a building ? A) position the exhaust outside the building .
Q) how should cylinders containing Liquefied Petroleum Gas ( LPG ) be stored on site ? A) in a locked external compound at least 3 metres from any oxygen cylinders .
Q) when working in a riser, how should access be controlled ? A) By a permit to work system .
Q) which of the following electrical equipment does not require portable appliance testing ? A) Battery-powered rechargeable drill .
Q) what must be clearly marked on all lifting equipment ? A) the safe working load .
Q) what is the first thing you should do after getting on to the platform of a correctly erected mobile tower ? A) Close the access hatch to prevent falls of personnel, tools or equipment .
Q) when assembling a mobile tower what major overhead hazard must you be aware of ? A) Suspended electric cables .
Q) when a new piece of plant has been installed but has not been commissioned, how should it be left ? A) with all valves and switches “ locked off “
Q) who is permitted to work with refrigerant gases ? A) A competent, trained person .
Q) what is the colour of an acetylene cylinder ? A) maroon .

 

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2330 – level 3 Unit 1 . 301 / paper 3 :- some old papers

1) the power in a three-phase circuit can be calculated using which one of the following formulae :-
►P = √3VL x IL cosθ.
P = VL x IL sinθ.
P = VL x √IL cosθ.
P = √3VL x IL sinθ.
2) the difference between the synchronous speed and rotor speed in a three-phase induction motor is called the :-
a) offset. B) drag. ►C) slip. D) phase angle.
3) When someone has received an electric shock is the first action would be to :-
a) apply resuscitation.
b) locate the isolator.
►c) raise the alarm, call for help or get someone to go for help.
d) check for moisture.
4) Thyristors conduct when a trigger voltage is applied to the :-
a) drain. ► b) gate. c) base. d) junction.
5) with a TN-C-S three-phase and neutral supply an isolator must :-
► a) break all phases.
b) break all phases and neutral.
c) break the neutral only.
d) break the phase, neutral and earth conductors.
6) Semi-conductor diodes :-
► a) allow current to flow in one direction only.
b) let current through when triggered.
c) amplify current and voltage.
d) are bi-directional.
7) the total impedance of capacitors, inductors and resistors in series can be calculated using :-
► a) Z = √ [ R2 + ( XL - XC )2 ].
b) Z = √ [ R2 + XL2 - XC2 ] .
c) Z = R2 + ( XC2-XL2 ).
d) Z = √ [R2 - XL2 ].

 

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RCD - Principles of operation

An RCD is designed to operate and isolate the circuit from the supply when there is an imbalance in the phase and neutral currents above a certain value. Any imbalance must either be the result of current leakage from the phase or from the neutral conductors to earth as, in normal operation, all current should be returned via the neutral conductor. As the earth impedance is unlikely to be zero, any ‘earthed’ metalwork would rise in potential, which would lead to a risk of shock.

► The basic construction of an RCD consists of three windings on a transformer core:

► When there is an imbalance in the phase and neutral currents the magnetic flux in the core will cause a current to flow in the third winding. As the current in this third winding increases, the magnetic trip will operate and disconnect the supply from the equipment. The trip current is arranged to be that at which the desired RCD characteristic is achieved.

► The RCD will trip at a much lower current than that required to break a conventional fuse or to trip a miniature circuit breaker. ◄◄

► If a person touches the phase conductor on the load side of the RCD this will also imbalance the supply, by creating a leakage path to earth, and trip the RCD.

► A Built-In ‘ Test’ Button can be Used to Place a Load between the Output Phase Conductor and the Input Neutral Conductor, Creating an Imbalance in the Windings - this Imbalance Causes the RCD to Trip. However, the ‘ Test’ Button Only Demonstrates that the Trip Mechanism Works, Confirming Nothing Else about its Specific Operational Characteristics.

 

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H&S Legislation

The Electricity at Work Regulations 1989 specifically deal with electrical “systems” in Regulation 4:
(1) All systems shall at all times be of such construction as to prevent, so far as is reasonably practicable, danger.
(2) As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as is reasonably practicable, such danger.
(4) Any equipment provided under these Regulations for the purpose of protecting persons at work on or near electrical equipment shall be suitable for the use for which it is provided, be maintained in a condition suitable for that use, and be properly used.

 

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► where an RCD is Used to Supply ►Band(S) ◄ Equipment, the Individual Items must be Tested for Earth Continuity to Any Metal Chassis as the RCD ◄◄ is Only the Secondary Protection Reducing the Severity◄◄◄

►For portable units the “ test “ button should be operated before every use at a new site to ensure that it is functioning , any device failing to trip must be removed from service ( and destroyed/disposed of ) immediately

Maintenance and Testing of RCDs
all RCDs are suitably maintained, and where appropriate, tested by a competent person

► an RCD is Used wherever Transportable or Trolley-Mounted Equipment is being Used which are Identified as having Added Risks Due to their Frequent Movement

► an RCD is used whenever long cables and extension leads are being used where it is unlikely that the required ►fuse disconnection time would be met◄

► all Workshop Areas are Fitted with RCDs which are Rated at 30mA / 40mS or better

Use of RCDs
RCDs MUST be Used in Conjunction with an Overload Protection Device such as an MCB. ◄◄

► If this Disconnection Time Cannot be Achieved by Fusing Alone then an RCD Must be Used. ◄◄