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All 3 Lights are 150 Watts . How much Current flows in the Neutral Wire .
a) 0 Amps . *
b) 1.2 amp .
c) 2.4 amps .
What does an “ Infinity “ Reading on an Ohm Meter Indicate .
a) Open Circuit . *
b) Short Circuit .
c) DC Circuit .
* Zero Indicates a Closed Circuit
* While Infinity Indicates an Open Circuit .
A Material with better Conductivity than Copper is .
a) Aluminium .
b) Silver . *
c) Steel .
a Parallel Path of Low Résistance is Commonly Referred to as .
a) Resonance Circuit .
b) Short Circuit .*
c) Open Circuit .
in a Transformer . the Oil is Primarily Used for .
a) Insulating .
b) Lubrication .
c) Cooling . *
If the Voltage to a Circuit Increases . the Current .
a) Increases . *
b) Stays the Same .
c) Decreases .
Most Electricity is Produced by .
a) Magnetism . *
b) Chemical Reaction .
c) Pressure .
In Flemings Left Hand rule . what Direction does the First Finger Point .
a) North .
b) The Direction of the Magnetic Flux . *
c) South .
A Transformer Changes a.c. to d.c.
a) True .
b) False . *
what kVA rating is Required for a Transformer that must Handle a Maximum Load Current of 8A with a Secondary Voltage of 2 kV.
a) 4 kVA
b) 8 kVA .
c) 16 kVA . * x
An Arrow drawn through the Schematic Symbol of an Inductor Indicates that the Inductor is .
a) d.c.
b) a.c.
c) Adjustable . *
Inductance is the Property of an Inductor that Produces an Opposition to any Change in Current .
a) True . *
b) False .
A Voltmeter Generally Reads .
a) Peak to Peak Voltage .
b) Average Voltage .
c) RMS Voltage . *
There are Two Groups of Test :
Dead & Live .
Dead :- Test Prior to the Installation being Energized . ( Before )
Live :- Test Following Installation being Energized . ( After )
Live Testing : is to Ensure that Once Energized . The Protective Device are Suitable for the Fault Currents Likely to Occur & will Operate Correctly in the Time Specified by the Regulation’s in the Event of a Fault
Dead Testing : is to Ensure that the Cabling has not been Damaged . & The Electrician has Not made any Mistakes .& that the Circuit(s) are Safe to Energise .
● Reference to maintained and non-maintained systems are made to ? ( Emergency lighting installations )
● The industry body that represents and negotiates on behalf of employees in the electrical contracting industry is the ? ( JIB )
● A large industrial panel feeding a large factory has several components installed to monitor voltage current and power consumption . this is known as ? ( Instrumentation )
● A component installed to detect increase in temperature is known as a ? ( Heat Detector )
● A measurement of 600mm taken off a site drawing that has a scale of 1:100 equates to ? ( 60 meters on site )
● A measurement of 20mm taken off a site drawing that has a scale of 1:20 equates to ? ( 0.4 meters on site .)
● BS-7671 is Classed as a ? ( Non statutory document )
● Which of the following is necessary for an electrician to install equipment on a construction site ? ( Drawings & Diagrams )
● When work is expected to be performed on an existing live circuit we should ? ( Safety isolate the circuit first )
● Fibre optic cabling is used in the transmission of ? ( Data )
● A tender to apply to undertake work is normally completed by the ? ( Estimator )
● The responsibility for health & safety when working in a domestic situation is ? ( The person carrying out the work )
● When considering the completion of work under live conditions . what must we do first ? ( Perform a Risk Assessment )
● What system can control heating & ventilation within a construction via a series of sensors ? ( Building management system )
● A foreman ? ( Runs the day to day operations on a construction site )
● Working in areas that have a higher than normal dust content should necessitate the need for ? ( A respirator )
● One method of ensuring that site drawings are easy to interpret is by using ? ( BS-EN 60617 symbols )
● The main purpose of a circuit diagram is to show how the installation ? ( Functions )
● The amount of electrical current that has the potential to kill is approximately ? ( 0.05A )
● Installation of a complicated piece of machinery should be completed using the working drawings and ? ( Manufacturers instructions )
● the IEE Wiring Regulations’ give advice on electrical installation but is fundamentally based on ? ( The Electricity at Work Regulations )
● The simplest method of displaying for a large installation is by a ? ( Block diagram )
After Midnight 2.02 minutes past
• A force of 20kN moves an Object a distance of 5m . the work done is ( 100kJ ) * Work Done = Force x Distance .
• MIMS cable comes with the Option of being sheathed or unsheathed . where might you use sheathed cable : ( In areas of high moisture content )
* Reduces the chances of the insulation getting damaged .
• A miniature circuit breaker conforms to what British Standard : ( BS-EN 60898 )
* European Standard .
• Which of the following from the list is the best conductor of electricity : ( Platinum )
* The most expensive too .
• An ammeter used to record current is connected in : ( Series )
* Current stays the same in Series .
• A standard circuit draws 5A and feeds a load with a résistance of 0.5Ω . what will be the total power : ( 12.5W )
* P = I Squared x R .
• Excess current flowing in a circuit that is electrically sound is known as : ( Overload Fault )
* Not a Short or Earth Fault .
• The r/ms value of a sine wave is calculated using the peak value multiplied by : ( 0.707 )
* 0.707 .
• Before being used . a ladder must be inspected by : ( Intended User ) YOU
* hopefully you before you get up there .
• An 110V transformer designed to be used on a construction site is Centre Tapped for additional protection to : ( 55V to Earth )
* Reduce voltage to Earth .
• The cables connecting together Extraneous Conductive Parts to the main Earthing Terminal are called : ( Equipotential bonding conductors )
* To maintain an equal potential .
• if Non-sheathed cables are specified on an installation they should be : ( Installed in conduit or trunking )
* Have some Mechanical protection .
• if a copper busbar is drawing a current of 300A . what will be the Physical effect on the actual busbar : ( it will expand )
* Less heat more Résistance .
• Percentage efficiency can be calculated by : (
* Output/input times 100 .
• if 3 conductors equal in length and in length and with a resistance of 1.5Ω are connected in parallel . what is the total résistance : ( 0.5Ω )
* Use the reciprocal calculation . 1/Rt = 1/R1 etc .
• if the peak voltage is given as 200V . what would be the average voltage : ( 127.4V )
* remember 0.637 for the average value .
• Three resisters of value 1.0Ω . 1.2Ω & 1.8Ω are connected in series across a 24V supply . what is the total current drawn in the circuit : ( 6A )
* Ohms law & adding résistance in series .
• The SI : unit electrical pressure is the ( Volt )
* Difference in potential . also called the emf
• Losses occurred in a transformers can be the results of ( Eddy currents )
* Lost magnetic current .
• the ►►maximum operating temperature of XLPE insulated cable is ( 90°O ) Watch the Wording / Two XLPE Q) . 90°O / 70°O
* increased over PVC insulation .
• transformers usually have their windings laminated . this is done to reduce ( Eddy currents )
* The name of the current .
• The primary winding of a transformer is connected to the ( Supply )
* Primary = first side .
• A galvanometer can measure electrical current using ( Magnetic fields )
* Older style clamp on ammeters use the principle .
• Isolating transformers operate on the principle ( Mutual induction )
* Means 2 separate coils .
• if the magnetic flux in a coil is divided by the cross sectional area of the coil . the unit produced is measured in ( Teslas )
* Magnetic flux density .
• The application of the electromagnet can be clearly demonstrated in the construction of ( Relays )
* Thick of the effect of winding around a ferrous core .
• Standard voltages in the UK used for distribution to consumers are commonly ( 11kV : 400V : 230V )
* Think about domestic and industrial .
• One example of an exposed conductive part is . ( A metalclad one way switch ) it could be a 3-way / 2-way ( Metal ) Hands !!!!!
* Exposed = part of a electrical system .
• A metal gas pipe entering a building is classed as an ( Extraneous conductive part ) ◄
* Not part of a electrical system but can introduce a potential ..
• The external loop impedance of an installation is abbreviated to ( Ze )
* Earth fault loop impedance .
• Protection from fault contact can be achieved using ( ADS )
* When it happens . what should happen to the circuit .
• One example of an exposed conductive part is ( The outer casing on a single Phase Motor )
* Exposed = part of a electrical system .
• Excess current flowing in a Circuit that is electrically sound is known as ( An overload fault ) ◄◄
* Not a short circuit or earth fault then …
• One reason for using circuit breakers rather than other cartridge type fuses is ( Can be easily reset after a fault ) ◄
* How many do you need .
• An earthing system that uses a separate conductor as a return path for fault current is called ( TN-S )
IT ) TN-C-S ) TN-C ) TN-S ** )
• A single pole switch that forms part of a lighting circuit switches the ( Phase or Line Conductor )
* Single Pole . which is the important conductor .
• if a circuit supplies portable equipment outside the equipotential zone . it must also be protected by a ( RCD ) 17th Ed
* Supplementary or additional protection .
• TN-C-S systems use a PEN conductor . what does PEN stand for ( Protective earthed neutral )
* Combined Neutral & Earth
• Protection from electrical shock by direct or basic contact is afforded by ( Barriers & enclosures )
* Prevent them touching live parts .
• A high breaking cartridge fuse conforms to what British Standard ( BS-88 part 2 )
* BS-88 -
• if non-sheathed cables are specified on an installation they should be ( Installed in conduit or trunking )
* Have some mechanical protection .
3.03 / 3 hour & minutes ( Junior Mebers . ( PLEASE DO NOT send DOWNLOAD ) Amber
• a ) E = 2pΦN … 60 . ( Yes )
* Known as the emf generation formula . ( Yes )
• b ) E = ΦN … 60 x 2p .
• c) E = 2pΦN x 60 .
• d) E = N / 2p x 60 x Φ .
•• if a current of 200mA flows into a capacitor for 40mS . how much change will develop in the capacitor ( 8 mC )
* Quit .
• Made from a variety of materials . such as carbon . what inhibits the flow of current ( Resistor )
* Another work for inhibit .
• A kitchen installation contains a ring circuit with several appliances installed on it such as a dishwasher and a fridge . The RCD frequently trips . what might be possible cause . ( Nuisance tripping from earth leakage ) ◄◄
* it’s a pain in the backside .
• What is the best method of protection by a line Phase to earth fault ( RCD )
* What detects imbalances .
• Excess current that flows in a circuit which is electrical sound is known as ( Overload ) 17th Ed . p/27
* More and more and more .
• An office with a raised floor with an expectation that desks can be moved can be best supplied by a system of ( Busbar trunking ) * Plug in . plug out .
• A 30 kW 3-Phase delta connected motor has a power factor of 0.86 lagging . calculate the Line current ( 50.35A )
* Remember to take power factor into consideration .
• The best cable for supplying a remote part of an installation separated from the main building is ( XLPE/SWA )
* The strongest .
• Calculate the induced emf in a conductor with a length of 0.65m moving at right angles at a velocity of 2m/s through a magnetic field that has a flux density of 0.9 tesla . ( 1.17V )
* Hey Bill ?? .
• One method of improving the starting torque of a 3-Phase induction motor is to use ( Star/Delta starting )
* High torques start . low current run .
• A RCBO provides protection against ( Overload &/or Sort Circuit ) ◄ p/29 17th Ed . [ Earth fault current ]
* Best of both worlds ,
• How many numbers of turns are needed on a transformer if the primary windings are 1000 & the primary & secondary current are 5A & 20A respectively ( 250 turns )
* Follow the formula . Np/Ns equals VP/VS etc ….
• A cooper conductor has a resistivity of 1.78 x 10-8 Ω . Determine the résistance of 100m of 2.5mm2 ( 0.712Ω )
( Remember that . 10- Small 8 ) Resistivity times length divided by area .
• An earthing system that uses a separate conductor as a return path for any fault current is called ( TN-S )
* Separate . as in . both separate all the Time .
• Which supply system uses the neutral conductor also as an earth ( TN-C-S )
* What does PEN stand for ? .
• a circuit consisting of an inductance of 0.12H is connected to a 50Hz supply . the inductive reactance is ( 37.7Ω )
* Two times ( pi ) times frequency .
• The rotor conductors of a 3-Phase cage rotor inductance motor are constructed of solid conductors ( Shorted et each end of rings )
* Hint !! We need a current through them to create a magnetic field .
• Capacitors can be connected across the supply terminals’ of an electrical circuit to ( Reduce the supply current )
* Reduced power reduces the ……
• An eight pole motor operating on a 50Hz supply would have a Synchronous speed of ( 750 rpm ) you will get Cals . in working Sparkie ????
* Frequency divided by Pairs of poles .
• A purely capacitive circuit contains 2 capacitors in parallel of sizes 10µF & 36µF . has a supply frequency of 50Hz and a total current of 12A . what is the total power dissipated in a circuit ( 0W ) ◄
* Purely capacitive …. Think about it .
• Cables that provides a reduction in emission of toxic gases and has a higher operating temperature than PVC are known as ( LSF cables )
* Low smoke & fume .
• Speed control of a 3-Phase wound rotor induction motor can be achieved by ( Adjusting resistance across the slip rings )
* It’s dictated by current . what affects current .
• In order to improve the power factor of an inductive system ( A capacitor is connected across the supply )
* The opposite of inductance .
• The peak inverse voltage of a 10V diode is ( 20V )
* Twin peaks .
• The light loss factor is used in the calculation for illuminance . what is it for ( The total light depreciation at a given time compared to when brand new )
* Things get old . like us . they don’t work so good .
• A series a.c. circuit has a resistance of 3Ω and an inductor of 0.0127H connected across a supply frequency of 50Hz . what is the total circuit impedance ( 0.5Ω )
* Reactance & pythagorus will lead the way
• A standard iron cored transformer works on the principle of ( Mutual induction ) ( PLEASE DO NOT send DOWNLOAD )
* Affects another coil .
• Speed control of a 3-Phase induction motor can be achieved by ( Changing the voltage applied to the stator )
* What can be increase to increase or Decrease the current .
• A 90 mF capacitor is connected to a 100 Volt d.c. supply . calculate the charge stored in the capacitor ( 9 coulombs )
* Capacitance time voltage .
• A conductor 300m long is placed in and at right angles to a magnetic field with a magnetic flux density of 0.3 tesla . what is the force on the conductor if a current of 36A is passed through it ( 3.24 N )
* Hey Bill .
• A transistor can be used as ( A Switch )
* sometimes on . sometimes off .
• When starting a 400V 3-Phase cage rotor motor using a star/delta starter . the voltage across each stator Phase is ( 230 V start 400 V run ) ◄◄
* Less voltage . more current .
• The most common method of speed control on an induction motor is ( Frequency control )
* How do we calculate synchronous speed .
• A 4 pole 50Hz three phase induction motor has a 4% slip . the rotor speed will be ( 24 rev/sec )
* Work synchronous speed first then work back .
• The current produced in the rotor bars of a cage rotor motor is caused by ( Mutual induction )
* The stator affects the rotor .
• An RCD used as additional or supplementary protection on a circuit should be rated at ( 30mA )
* Touch voltage to be taken into account .
• A small heating circuit draws . 1.5kW of power and has an internal resistance of 0.38Ω . what is the total voltage drawn ( 24V )
* What are the formulas for calculating power .
• Which of the following is an acceptable method of obtaining an earth connection for a TT system ( Structural steel embedded in the ground )
* Which is the only one that cannot change .
• A circuit contains 3 capacitors in series of size . 19µF . 24µF & 32µF . what is the total capacitance in the circuit .( 8 µF )
* Capacitors add the opposite to reistors .
• Motors over the size of 0.37kW ◄◄ must have a means of ( Overload protection )
* Stop the motor running out .
• The type of motor stator which can be used on all cage motor ratings from fractional kW up to 1000 kW would be ( Soft Start )
* Not a hard start .
• A coil has self-inductance 1.5H , and the current through it changes from 0.8A to 0.4A in 0.02Sec calculate the emf . induced ( 30V )
* Change . over time . time inductance .
• A resistor and an inductor in a series circuit have a résistance of 6Ω and an inductive reactance of 8Ω respectively . what is the total impedance ( 10Ω )
* Follow Pythagorus .
• A supply system which uses the metal sheath of the cable to provide an earth connection is known as ( TN-S )
* Both separate .
• A silver band on a resistor indicates a tolerance of ( 10% ) Ps I got this when I was an Apprentice . this kind off Stuff !! : 90s
* Not as common . but still 10 star .
• A transistor can be used as ( An amplifier )
* Listen to that stereo .
• A capacitor start and run single Phase induction motor as a ( Two Phase motor ) Watch the Wording . ← ← ← ←
* Moves it out of Phase .
• In a star connected system . determine the line voltage if the Phase voltage is 660V ( 1143V )
* In star . IL = Ip .
• A four pole 50Hz three Phase induction motor is connected to a 400V supply . if the motor has 4% slip the rotor speed will be ( 1440 rpm )
* Work synchronous speed first work back from there .
• An increase in starting torque of a three Phase wound rotor induction motor can be achieved by ( Placing less résistance across the slip rings )
* More current can be achieved by .
• Protection of electrical cables in the event of a fire can be achieved by ( Installing FP200 cables )
* Fire proof .
• When a small voltage is applied to the base of a transistor . current flows between the ( Collector and the emitter )
* Collects and emits .
• When a single Phase capacitor start capacitor . run motor reaches its synchronous speed the centrifugal switch will ( Disconnect the start winding )
* What’s not needed when running .
• A streetlight contains a 2000cd light source 4m above the ground . What is the luminance directly below the lamp ( 125 lux )
* I/d -2 ( small 2 )
• A capacitor of capacitive Reactance 5Ω . an inductor of 8Ω inductive Reactance and a Resistor of 4Ω are connected in series to a 230V 50Hz supply . the total impedance of the circuit will be ( 5Ω )
* Pythagorus with a twist .
• A device consisting of 2 conductive plates separated from each other by a dielectric is known as a ( Capacitor )
* Two plates . think of the symbol .
• The star rotor windings of a 3-Phase wound rotor induction motor are connected in series to a bank of external resistors ( Slip rings & brushes )
* Think a.c. and how you connect power to a moving machine .
• A medium sized factory has a three-Phase load of 50 kVA & 30 kVAr Calculate the total kW ( 40 kW )
* Think & thank Pythagorus .
• In a capacitor start motor . the start and run windings are ( 90° out of Phase )
* Not quite 3 Phase degrees out .
• A short circuit is a ( Fault of negligible impedance between Line & neutral conductors )
* Virtually no résistance between them .
• A capacitor of 95µF is connected in parallel with a 20Ω pure resistor . the group is connected to a 230V . 50Hz supply . calculate the power dissipated in the circuit ( 2.64 kW )
* PURE resistor part should give it away .
• Simple D.C. rectification can be achieved by placing what into an A.C. circuit ( Diode )
* Lets through in one direction only )
• A conductor 500mm long is paced in and at right angles to a magnetic field with a magnetic flux density of 0.25 tesla . what is the current required in the conductor to create a force of 15N on the conductor ( 120A )
* Hey Bill .
Learning Curve
Part 1 : Scope . Object & Fundamental Characteristics
• An electric shock due to inadequate basic protection can be caused by
* Think about the definition of basic protection .
- The circuit protective conductor being touched under energisation .
- Touching the casing of a Class 11 portable drill .
- A person touching conduit under fault conditions .
- Brushing a Phase /Line conductor with your hand . ●
• IEE Regulations BS-7671 applies for
* What areas below do the Regulations cover .
- Electrical equipment on aircraft .
- Traction equipment .
- Fire alarms fed from a safety source .
- Construction sites . ● 110.1 Regs .
• Who is responsible for specifying the First periodic inspection on an installation .
* Who knows everything about an installation before the Other .
- The architect .
- The person responsible for the design . ●
- The electrical installer .
- The person ordering the work .
• An electric shock due to inadequate fault protection can be caused by
* Think about definition of fault protection .
- Accidental touching of a Phase/Line conductor .
- SELV terminals .
- Touching conduit under fault conditions . ●
- Class 11 equipment .
• An example of an exposed conductive part may be .
* exposed parts form part of an electrical system .
- Incoming lead water supply .
- Metalclad socket outlet cover ●
- An aluminium ceiling grid .
- A copper gas pipe .
• A single pole switch shall be connected in the
* If there’s only one pole . which is the most important .
- Earthing conductor only .
- Neutral conductor only .
- Across the neutral & Line conductor .
- Line conductor only . ●
• Class 11 equipment relies on basic insulation &
* Class 11 is also known as ►► Double Insulated .
- A circuit protective conductor .
- Supplementary insulation . ● Regs. p/21 . Read up .
- Bonded metal mechanical protection .
- Earthed equipotential bonding .
Remember : Class 11 equipment would provide . Basic & Fault Protection !!!!!!!!!!
• What is the maximum operating current for an RCD which may supply portable equipment used outdoors .
* Think about acceptable & common rated RCD.
- 20mA ) – 100mA ) – 10mA ) - 30mA ● )
• When designing an installation in licensed premises .
* There may be other factors to take into account .
- Additional statutory controls must be complied with ● 115.1.
- Drinking alcohol should be taken into account
- Consultation with the landlord should proceed the design proceed .
- Allowance should be made for future refurbishment .
• Basic protection protects .
* Against the most basic form of shock .
- Persons or livestock in contact with extraneous metalwork under fault conditions .
- Persons or livestock dismantling an item of electrical equipment .
- An unqualified person being allowed to work on electricity .
- Person or livestock touching a live conductor . ●
• A fireman’s emergency switch should be located .
* Think how the switch will be operated .
- 2.75m from the ground with the switches off position at the bottom .
- 2.75m from the ground with the switches off position at the Top . ● 537.6.4. (ii)
- 2m from the ground with the switches off position at the Top .
- 2m from the ground with the switches off position at the bottom .
• The electrical installation shall be designed for .
* Look in part 1 .
- The protection of persons & livestock .
- The protection of persons .
- The protection of persons . livestock & property .
- The functioning of an electrical installation & protection of persons . livestock & property . ● 131.1
( All the Words ) electrical installation : Safety persons : livestock & property : )
• When equipment is not covered by a known standard , the designer must confirm the same degree of safety as afforded by .
* A national fall back many items conform to .
- European Standards .
- Cenelec Standards .
- British Standards . ●
- IEC Standards .
After Midnight . 2.05 minutes
• Which of the following is not classed as a legal document ( BS-7671 )
* perhaps the one we use most often .
• The correct British Standard identification number for a 6A type B miniature circuit breaker is ( BS-EN 60898 )
* The most common written on test sheets .
• The term reasonably practicable means ( Weighing a risk against the trouble . time & money needed to control it ) ◄ -&-s
* Should do everything we can . ◄◄◄
• BS-7671 Requirements for electrical installations sets out to protect ( Persons . property & livestock )
* Every Man . Woman . Cow & where they live . etc ….
• BS-7671 Guidance Note 3 covers ( Inspection & testing )
* A very useful one to have in the van .
• What other British Standard covers . earthing & lighting protection ( BS-6651 )
* you either know it or you don’t .
• The term system means !!!
* The start . middle & end .
- Any conductor in a system which is intended to carry electric current in normal conditions , or to be energised in normal conditions .
- Anything used . intended to be used or installed for use . to generate . provide . transmit . transform . control or use electrical energy .
- A conductor of electrical energy .
- An electrical system in which all the electrical equipment is . or may be . electrical connected to a common source . ●
• Which one of the following is covered by additional special regulations not in BS-7671 ( Storage of petroleum ) !! The big Bang Theory “
* The most dangerous .
• Which part of the Electricity of Work Regulations covers competency ( part 16 )
* What sort of hint , it’s part 16 .
• The Electricity at Work Regulations states with regards to working on live conductors ( Should be avoided in all circumstances’ unless otherwise unavoidable )
* We shouldn’t and we know it . but sometimes .
• BS-7671 is divided into how many parts ( 7 parts )
* 7 main parts .
• Which part of the Electricity at Work Regulations covers Earthing ( part 8 )
* What sort of hint . it’s part 8
• if an item of equipment conforms to BS-EN standards it means ( it conforms to European standards )
* EN is short for .
• What other British Standard covers Fire detection & Fire alarm systems ( BS-5839 )
• Which one of the following is covered by additional special regulations ( lightning protection )
* BS-6651 covers the installation as well .
• BS-7671 The IEE wiring regulations covers al of the following except one that has additional regulations ( lightning protection )
* BS-6651 covers this type of installation .
• Which of the following is classified as a legal document ( the Electricity at Work Regulations )
* The big electrical document issued by the Government .
• Which part of the Electricity at Work Regulations covers the installation & protection of conductors ( )
* Part 7 .
• Emergency lighting is covered by BS-7671 and what other BS regulation ( )
* BS 5266 .
s/20
After Midnight . 2.05 minutes (2)
• The regulations define Extra Low Voltage as ( 50V a.c. )
* Not quite that low but still .
• Guidance on the correct selection . use & inspection & testing of electrical installations can be found in ( BS-7671 )
* Part 6 .
• The statutory regulations that cover people working on electrical installations are ( the Electricity at Work Regulations )
* To much .
• The term absolute means ( Must be met regardless of cost )
* Absolutely absolutely .
• BS-7671 IEE Wiring Regulations apply to ( Electrical contracting )
* What do we do every day .
• The BS number for standard 13A socket outlet system is ( BS 1363 )
* Not the breakers or plug top fuses .
• Additional information when working with large motors can be taken from ( Manufacturers data charts )
* Some produce a lot of additional useful information .
• The correct table showing maximum fixing & clipping distance can be found ( The O/S/G.)
• A wiring diagram shows ( The actual connection of conductors )
* how things connect together perhaps .
• When preparing a quotation for an installation . the best item to use are ( Layout drawings and take off sheets )
* What and where .
• One method of ensuring that site drawings are easy to interpret to interpret by all parties is by using ( BS-EN 60617 symbols )
* The defacto symbols standards .
• The progress of an installation can be best monitored by ( Work & time sheets )
* What’s happened and when .
• When items are delivered to site . they should be checked against the ( Delivery note )
* Obvious one . clues in the question .
• Progress on a large electrical installation can be best organised by ( Bar chart )
* One to the next to the next ……. Pint !!
• An exploded view diagram from manufacturers shows ( Complex components split apart )
* if it’s hard to understand .
• Symbols used in electrical installation design can conform to ( BS-EN 60617 )
* The European Standard .
• When preparing to begin an installation . a list of materials will be drawn from the ( Drawings & specification )
* Count and check .
• On completion and handover of an installation . the client should receive ( An operations manual )
* So that the installation can be used .
• Which of the following information is not provided on a layout drawing ( Cost of the installation )
* Where . what . how big but not .
• In situ measurements can be taken ( By measuring quantities on site )
* In situ means in Place .
• Complex electrical systems may be better understood by referring to ( Manufacturers manuals )
* They may contain useful extra information .
• Day work is ( Additional work carried out outside of the main contract )
* Extra .
• Which of the following is necessary for an electrician to install equipment on a construction site ( Drawings & diagrams )
* Where and what do we install .
• What documents lays out in detail the requirements of an electrical installation before it starts ( Specification )
* Big written document with loads of information .
• At the end of a working week . an electrical operative should complete a ( Time Sheet )
* Allows costs to be forwarded to a job .
How’s about Big thanks You.s Amber.
After Midnight . 2.05 minutes (3)
• An RCD installed as additional protection for socket outlets should be rated at ( 30mA )
* Touched voltage applies here .
• Large armoured cables are most suitably installed in ( Ladder racking installations )
* Big special type of tray .
• The interior of a bathtub is classified as ( Zone O )
* Nothing )
• An earthing system called TN-C-S is also known as ( A PME system )
* More than one Earthing point .
• Contactors are commonly used on ( Motor control circuits )
* Think of direct online starter .
• Socket outlets on a construction site not protected by SELV should have additional protection via a ( RCD )
* How do we add protection to a circuit that is already protected by an MCB .
• Simple control of a central heating system be achieved by using a ( Thermostat )
* A lot of houses have these for their systems .
• Main factors that would influence the choice of wiring systems are ( Ambient temperature and Mechanical damage )
* Environment and external influences .
• A simple wall mounted room thermostat operates by using a ( Bi – metallic strip )
* A piece of metal that bends when it gets warm
• if the calculated voltage drop at the load was unacceptable . what is one action you can take ( )
* Less résistance .
* Increase live conductor sizes . ••••
* Increase the voltage at the supply .
* Increase earthing conductor size .
* Decrease CPC size .
• Underfloor pressure pads are commonly used in ( Security systems ) “ “Not underfloor Heating “ ”
* When people step in places they should,t be .
• One advantage of proprietary cables such as FP200 compared to MIMS is ( Quicker to install )
* No better protection but no specialism required .
• If an electrical circuit supplies equipment outside the Equipotential Zone a ( RCD must protect the circuit )
* Think of what protects us outside the Equipotential Zone .
• Which earthing system can use the outer sheath as an incoming earth ( TN-S )
* Both separate .
• Magnetic door contacts placed at the top or bottom of door frames are used in ( Security systems )
* When a door is opened that should,t be .
• A 4mm2 conductor has a design current of 20A and a length of 20 meter. If the voltage drop is 11mV/A/m what is the voltage drop at the terminals’ ( 4.4V )
* Remember the formula mV/A/m x Ib x I divided by 1000 .
• A radial circuit is protected by a 30A semi enclosed fuse . what is the tabulated current carrying capacity of the cable supplying the circuit assuming no other correction factors apply ( 41.4A )
* Remember . it’s protected by a BS-3036 fuse .
• PVC conduit should be avoided outdoors because ( UV rays can damage the construction )
* The sun is very damaging .
• In a high moisture environment . what would be the preferred choice of wiring system ( PVC/PVC cable in trunking )
* Remember . conducting & corrosion .
• A component designed to operate an item of electrical equipment under normal conditions is known as ( A switch )
* We use one every day .
• Installations that require minimal disturbance of building fabric are best installed in ( Bare MIMS cable )
* some jobs specify this . especially rewires of old properties .
• The purpose of a protective device at the origin of the circuit . ( Protects the circuit conductors and cable ) ◄
* Doesn’t necessarily protect us .
• What supply system uses the neutral conductor as an Earth ( TN-C-S )
* PEN or PME .
• A lighting circuit is controlled by two 2-Ways and Intermediate switches . this is known as ( Functional switching ) ◄
* Everyday type of switching .
• An Edison screw lampholder should have its centre pin connected to the ( Line conductor )
* it’s the part that makes it Glow .
• An increase in the ambient temperature will result in ( Decrease in the current carrying capacity of a conductor )
* The higher the heat . the lower the current capacity .
• The installation of fibre optics and Cat 5e cables requires ( Specialist knowledge & Training )
* Do you know what you are doing .
• A 1.5mm2 conductor has a design current of 4A and a length of 10 meters . if the voltage drop is 29mV/A/m what is the voltage drop at the terminals ( 1.16V )
* Remember the formula mV/A/m x Ib x I divided by 1000 .
• The IEE regulations advise that construction site should be tested ( Every three months )
* Quite frequently .
• Three fluorescent fittings rated at 60W each will draw how much current ( 1.4A )
* Don’t forget the discharge part of things .
• When installing PVC conduit in areas of fluctuating temperatures ( Expansion joints should be used )
* What happens when things get hot and cold .
• Maintained emergency lighting ( is switched as a normal part of a circuit and lights in the event of power failure ) ◄
* Those little Red LED fittings you see dotted about .
• A 10kW shower in a normal domestic situation will draw how much current ( 43.5A )
* The good old power formula .
• Isolators are designed to operate under ( No load conditions ) ◄
* Not when they are on .
• An earth fault current will flow in a installation when ( A line conductor comes into contact with an exposed conductive part )
* The earth fault loop path
• The type of control system used in conjunction with heating & ventilation systems is known as ( Environmental control )
* it’s all around us .
Assessment of general characteristics’ " Lerning curve "
• Fault protection protects against ( Electric shock under fault free conditions )
* Not necessarily in contact with an electrical system .
● ( Fault Protection : p/24 ) Protection against electric shock under single-fault conditions :::::::::::::: 17th Ed .
• Current carrying capacity is defined as ( The maximum amount of current carried by a conductor under specified conditions )
* The amount of current .
• A neutral can be defined as a ( Live conductor ) ◄◄
* is it protective ? . is it a live .
• An example of a Band 1 circuit might be ( A telephone cable installed in a domestic property )
* is it protective ? is it a Line ? ( With Telephone Line !! does not Mean Line/Live conductor as in Power 230V ) p/31
• A circuit protective conductor is ( A protective conductor providing a connection between exposed parts and the main earth terminal )
* CPC is commonly called earth but what part of earth .
• SELV denotes an extra low voltage system that is ( Electrically separated from the general mass of earth )
* What does the S stand for .
• A bonding conductor is ( A protective conductor providing Equipotential bonding )
* Connects to the services ………….. Etc.
• A final circuit is defined as the wiring between the ( Distribution board 2391 / 2392-10 . Consumer Unit and current using equipment )
* Final as in …. Last bit.
• An earth conductor is ( A protective conductor connecting the main earthing terminal of an installation to an earth electrode or other mean of earthing .
* The main baby .
• A double insulated hand held electric drilling machine is known as ( Class 11 equipment )
* Think about where you see the symbol .
• An example of a Band 11 circuit might be ( take you best shot ?? Ring ) p/31
* is it protective ? is it a Line ?
• The following are all reasons for dividing a circuit except ( Allow for future expansion within the electrical installation )
* One requires more than just room in an installation .
• Which of the following is considered an external influence according to part 5 ( Ambient temperature )
* Usual influence .
• Every installation shall be divided into circuits to ( Reduce electromagnetic interference )
* Stop the influence within circuits .
• Which of the following forms part of the assessment of general characteristics ( Maintainability )
* Look in part 3 .
• Any overcurrent protective device installed at the Origin of a circuit must have a breaking capacity of ( Equivalent or more to the prospective short circuit current ) ◄◄
* What causes the maximum current to flow under fault conditions .
• Correct coordination between conductors and overcurrent protection device is achieved when ( In is not less than Ib ) ◄◄
* Do you want the breaker to trip when full load is applied .
• Which of the following forms part of the assessment of general characteristics ( External influences )
* Look at pat 3 .
• When classifying an area for external influences . the code given to an are that had a high ambient temperature would be ( AA )
* Appendix 5 .
• it is recommended when calculating the demand for discharge lamps a multiplying factor should be applied . what is the factor ( 1.8 ) ◄◄
* it takes into account starting currents .
• An overload current could arise when ( Excessive mechanical load is applied to an electric motor .)
* Overload occurs in normally healthy circuits .
• Installation should be arranged so as to avoid danger in the event of a fault . and to facilitate safe operation . inspection . testing & maintenance . one method of complying with this is to ( Divide the installation into Band of circuits )
• Which of the following is not considered an external influence according to part 5 ( Machinery & Plant )
* An external influence not from human origin .
• Which of the following does not fall under compatibility ( Unbalanced loads ) (iii)
* Look up 331 .
After Midnight . 2.05 minutes (4)
• MIMS cable clipped direct to the structure of the building is most effectively fixed using ( P clips )
* All round clips for integrity .
• When installing metal trunking system ( Earth continuity tags must be used )
* Don’t forget that metal conduits to .
• The prevention of electric shock on a construction site can be most effectively reduced by ( Using a battery tool )
* Totally separated from electric source .
• Minimum bending radii for conduit is necessary to ( Ease drawing in reduce stress on conductors )
* So it doesn’t squeeze the cables at one point
• The most accurate method of installing very short vertical SWA cable runs is using a ( Plumb bob )
* Simple old fashioned device .
• Forming 90° bends in steel conduit can be more accurately achieved by using ( A bending machine )
* Present tool .
• The first test to be carried out on a completed lighting circuit is ( Continuity CPC )
* The most important one .
• The most accurate method of installing long horizontal conduit runs is using a ( Laser level )
* Set it up and follow the dots .
• Lengths of SWA installed in a large warehouse can be best fixed using ( Girder clips )
* A large warehouse is unlikely to have a ceiling .
• During the installation stage , conduit should be deburred with a ( Reamer )
* Sometimes also called deburrer .
• When using the R1 + R2 method for determining continuity of CPC . we can commonly also perform the ( Polarity )
* Does it work correctly .
• The most suitable fixing device for conduit to be embedded into the structure is ( Crampets )
* Cheap but effective method .
• A lighting circuit has had it’s continuity of CPC tested using the wander lead method . how is this ( R2 )
* Like the star wars Robert . but without the D2 but …………
• After completion of work on a construction site . you should ( Leave the site clean & tidy & store materials & tools in a safe . secure place )
* Safe & secure .
• The most common fixing method for clipping SWA direct is ( Cleats )
* Like clips for armoured .
• Before and during the carrying out of an insulation résistance test . it is necessary to ( Just some off )
- Operate any two way & intermediate switches in lighting circuits .
- Remove lamps from lighting circuits .
* A few things to remember .
• When manufacturing a 90° bend in steel trunking . the most effective tools for making the trunking are a ( Tri square with set 45° angle & scribe )
* A 90° bend is fabricated by splitting the angle in two .
• After performing a lamp change on an installation what should you do with the old lamps ( Return them to a suitable disposal facility )
* Ready for moving on .
• Any left over waste materials on a construction site must ( Be stored in suitable containers of site )
* Ready for moving in .
• Space factors are recommended by BS-7671 to ( Allow dissipation of conductor heat )
* A lot of cables can generate a lot of .
• When fixing large switchgear to concrete walls . the most effective devices are ( Masonry bolts )
* The big bolts .
• The most common fixing method for surface fixing to plasterboard is ( Spiral fixings )
* Windy fixings make their own hole .
• The most common fixing method for conduit systems are ( Spacer bar saddles )
* Standard saddles .
• Why is it necessary to perform a continuity of CPC test on a completed circuit before all the other tests ( Each subsequent test relies on the integrity of the CPC ) ◄◄
* What are the next tests . will they work properly .
• An insulation résistance test is necessary to ( Confirm the integrity of the insulation )
* Check the résistance of the insulation perhaps .
• The most effective tool for removing burrs within trunking is ( A file / Deburrer )
* A good old fashioned tool used for metal .
• Before beginning work on an electrical circuit ( It should be isolated and locked off ) ◄◄
* Safety first always .
• If a hole is to be made in the building fabric to allow trunking to pass through ( Suitable arrangements should be made to prevent the spread of Fire ) ◄◄
* Don’t let it spread .
• Any portable equipment used on a construction site should ( Be checked before & after use for damage )
* Safety first always .
• A fuse protecting the plug top . must conforms to ( BS-1362 )
* The only plug top one there is .
• Conduit runs should have boxes installed regularly to ( Enable easier drawing in of cables )
* Don’t drag them through too far .
• The most accurate tool to mark steel trunking for cutting is ( A Scribe )
* Get the most thinnest line to follow you’ll be aright .
• When installing electrical equipment in the basement of an industrial installation . what should we take into account .( Rodent damage )
* What can cause a lot of damage .
• Steel conduit used for lighting runs is to be connected to trunking for the longer runs . what is the best method of terminating the conduit into the trunking ( Brass bush & coupler )
* Typical method .
• A stop button is used to protect a motor circuit . what is important about this type of circuit ( It must be impossible to re energise unintentionally )
* Reset the button . what don’t we want to happen .
• Distance saddles might be used in area ( of high condensation )
* They move the conduit further off the wall .
201-2
• Which of the following would not involve electrotechnical activities ( Automotive wiring companies )
* They are specifically left out of the regs :
• Reference to maintained and non-maintained systems are made ( Emergency lighting installations )
* Some come on normally . others in mains failure .
• What system can control heating and ventilation a construction via a series of sensors . ( Building management system )
* Looks after the whole ………
• A tender to apply to undertake work is normally completed by the ( Estimator )
• A component installed to detect increases in temperature is known as a ( Heat detector )
* Remember there are 2 distinct types .
• Category 6E cabling used in transmission of ( Data )
* Transmits signals .
• A standard ring final socket outlet system is known as a ( Power installation )
* Transmits electricity for general use .
• The jointing of high voltage cables is usually used in ( Distribution networks )
* Moving electricity from one building to another .
• High voltage cable jointing is usually carried out by ( Regional electricity companies )
* Supply companies .
• The industry body that represents employers in electrical contracting is the ( ECA )
* Electrical contracting ……….
• A foreman ( Runs the day to day operations on a construction site )
* Should be making sure you do your job correctly .
• Fibre optic cabling is used in transmission of ( Data )
* Transmits signals via light .
• A system installed to detect the presence of unwanted personnel is known as a ( Security installation )
* Sometimes called burglar alarms .
• The industry body that represents and negotiates on behalf of employees in the electrical contracting industry is the ( JIB )
* Sort out your wages rates .
• A series of pumps and machinery are to be linked together to perform various duties towards the same outcome . this would be known as a ( Control system )
* Everything is ---------- by a single system .
• An estimator is responsible for ( Pricing a potential installation )
* Estimating how much .
• A large industrial panel feeding a large factory has several components installed to monitor voltage . current & power consumption . this is known as . ( Instrumentation )
* Items used to measure thing are called ………..
• A system installed to detect flames or smoke is known as a ( Fire alarm installation )
* easy one here .
• A contracts manager ( Oversees an installation build from start to finish )
* Quite high up in the chain .
• A high voltage supply is normally installed by ( The regional supply authority . )
* Transmission * distribution .
Inspection & Testing – 6
• A polarity test is conducted to verify that ( Every fuse and single pole device is connected in the line conductor only )
* Things work and are protected
• When installing 3-Phase equipment . what additional test should be carried out ( Phase sequence test )
* Maybe the motor spins the wrong way .
• A legible chart . diagram or table relating to the installation should provide information relating to ( The identification of circuit protection )
* Can easily locate the …… in event of fault . maintenance etc .
• An earth fault loop impedance test performed on a ring final circuit will record ( The résistance of the line conductor . protective conductor & external loop impedance )
* Kit . bang . Kaboodle .
• The minimum value of insulation résistance test performed on a PELV installation is ( 0.5MΩ )
* Look up part 6 . SELV –PELV : 250V d.c. ≥ 0.5MΩ . Table 61 .
• An electrical installation certificate must indicate responsibility for the installations ( Design . construction . inspection & testing )
* Start . middle & end perhaps .
• A polarity test should be carried out ( Before the installation is energised )
* Pre or post is the question . or maybe dead or live ?
• The minimum value of insulation résistance test performed on 230V a.c. installation is ( part 6 )
* Look up part 6 . Table 61 . 500V d.c. ≥ 0.1MΩ .
• A minor works certificate should be issued where ( An alteration not requiring an additional circuit needed . )
* Small works .
• An insulation résistance test performed on a PELV installation should be capable of producing a test voltage ( 250V d.c. )
* Part 6 .
• An electrical installation certificate should be signed by ( A competent person )
* Know what you’re doing do we Sis .
• An insulation résistance test is conducted to verify that ( There is no breakdown of the conductor insulation )
* Pretty obvious .
• Before conducting an insulation résistance test you should ( Ensure that all voltage sensitive devices are taken are disconnected )
* Think about the voltage you are putting through .
• A periodic inspection report would be carried out on ( An existing property ) this Q) would be asked by -&-s 2392-10 .
* Over a period of time .
• Four of the tests on a completed installation required by BS-7671 are ( 2 . 3 . 1 . 4 )
1) Insulation résistance .
2) Continuity of protective conductors’ .
3) Continuity of ring final circuits .
4) Polarity .
Which of the following shows the correct sequence of these tests .
* Think about the sequence and what needs to come first .
• An insulation résistance test performed on a 50V a.c. SELV installation should be capable of ( 250Vd.c. )
* Look up part 6 .
• The frequency of a periodic inspection report on an older installation depends upon ( The type . use & operation of the installation )
* A rarely used building or a frequently used.
• The minimum value of insulation résistance test performed on a SELV installation is ( 0.5MΩ )
* Look up part 6 .
• Which one of the following items is included in the checklist during the initial verification of an ( Presence of diagrams & instructions )
* Something to help find your way around .
• Before conducting an insulation résistance test you should ( Ensure that all lamps are removed )
* What might confuse the readings .
• No alteration . temporary or permanent . shall be made to an existing installation unless the ( The existing equipment is adequate for an additional load )
• A test of continuity at each socket outlet of a ring final circuit is carried out to ensure that ( That the Ring is not Interconnected )
* What are the associated dangers .
Unit 2 :
Inspection & Testing & Commissioning .
1) List three widely used types of : ( it’s the Meaning of the Word -&-s always get’s you On )
a) Wiring system .
b) Wring enclosure .
Solution :- ( any 3 )
a) Micc cable .
PVC/SWA cable .
XLPE/SWA cable .
PVC twin & earth cable .
Fire retardant cable .
b) PVC trunking . ( any 3 )
Steel trunking .
PVC conduit .
Steel conduit .
Ducting .
2) When making an Area Safe to Work in :
a) List three Procedures to be taken before commencing work .
b) Describe the permit to work procedure .
Solution :-
a) Use barriers & tapes to cordon off an area .
Place warning signs in appropriate positions .
Isolate equipment from the supply .
b) The permit to work is a formal procedure in the form of written authorisation used to control work in potentially hazardous areas .
3) When carrying out large contracts .
a) List three parties likely to be concerned .
b) State the purpose of a site record .
Solution :-
a) Client .
Contractor .
Supplier .
Consultant .
Sub-contractor . ( any 3 )
b) Provides a continuous . updated record of all activities on site .
4) Describe the use of the following in monitoring the progress of a contract .
a) a Bar chart .
b) a Site diary .
c) Variation orders .
Solution :-
a) To display progress of different parts of a contract graphically .
b) A daily record of events on site .
c) Variation orders are requests for extra work or change to a contract and must be given in writing . the issue of variation orders may affect the main contract progress .
5) With reference to the application and use of residual current devices ( RCD )
a) list three situations where RCD protection is required .
b) State the primary function of an RCD .
c) Describe the term nuisance tripping . **
Solution :-
a) For sockets installed on TT earthing systems . For sockets outlets likely to supply portable equipment used out doors .
where satisfactory values of ( Zs ) cannot be achieved .
b) To limit the severity of electric shock .
c) When tripping occurs due to small leakage currents that do not constitute a real fault . **
Learning Curve Only
Q ) Which is the preferred method of Protection on the D.C. side of a Photovoltaic Power Supply . ?????? ( PV ) 17th Ed .
1) Class 11 or Equivalent Insulation. ( Take your best Shot )
2) Placing Out of Reach .
3) Non-conducting location .
4) Earth free local Equipotential Bonding .
( p/200 – 712.412. )
17th Ed . Protection by the Use of Class 11 or Equivalent Insulation shall preferably be Adopted on the ( D.C.) Side .
PS. This is the Only Book that gives you the Answer’s to your Qs .
This is Just to make you aware of the Q/As that -&-s will as you one day . Amber. ( what is a Motor/Caravan – Touring/Caravan ) it’s the Wording .
p/209 - PS . Electrical Installations in Caravans & Motor Caravans .
Q) The Maximum Interval between Periodic Inspection of a Touring Caravan is ??????
At this time your Scratching your Head . !! ( Fig . 721 – p/211 – Bottom of / Periodic Inspection
Preferably not less than Once Every Three Years . & Annually if the Caravan is Used Frequently ………… etc .
Q ) Regional Electricity Companies are Reluctant to Provide which of the Following to Construction Sites .??
a ) PME Supply . 704.411.3.1.
p/181 : A TN-C-S system shall Not be Used for the Supply to Construction Sites . Except for the Supply to a Fixed Building of the Construction Sites .
( PME : Protective Multiple Earthing )
1) The ( ESQCR ) Prohibit the use of a TN-C-S system for the Supply to a Caravan or Similar Construction .
2) Not Allowed in Certain Location’s i.e. Petrol Station’s .
b) TT Earthing System .
c) Single Phase Supply .
d) Three Phase Supply .
( PME ) Important to Ensure that the Neutral is Kept at Earth Potential by Earthing it at Many Points Along it’s Length / Hence “ Multiple Earthing “
An RCD that is Installed for Protection Against the Risk of Fire must be ?? -&-s
p/113 – 532.1 .
* The RCD shall be Installed at the Origin of the Circuit to be Protected .
Origin of an Installation . p/27
* The Position at which Electrical Energy is Delivered to an Electrical Installation .
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