Pregunta 1
Pregunta
What does Cg relate to in cable calculations?
Respuesta
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Grouping factor
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Ambient temperature
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Insulation factor
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Burred depth factors
Pregunta 2
Pregunta 3
Pregunta
When calculating maximum Zs for a circuit design what is the 1.2 multiplier used to account for?
Respuesta
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Increase in conductor temperature
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Human error in measurement
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Decrease in earth fault current
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Parallel paths
Pregunta 4
Pregunta
What is the maximum permissible voltage drop for lighting in a final circuit?
Pregunta 5
Pregunta
What is the formula for voltage drop?
Pregunta 6
Pregunta
What does In stand for?
Pregunta 7
Pregunta
If an RCD is to be for additional protection, how many tests should be carried out on it?
Pregunta 8
Pregunta
What is the rated current for an RCD that is to be used as additional protection?
Pregunta 9
Pregunta
What does maintenance factor in lighting design relate to?
Pregunta 10
Pregunta
Which out of the following relate to utilisation factor?
Respuesta
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Reflectance values of the ceiling, wall and floor
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How often people are using a room
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How often the lights are left on when people have left
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The floor area of the room being lit
Pregunta 11
Pregunta
A room is to be illuminated to 350 lux. The maintenance factor is 0.85, utilisation factor is 0.8 and the room measures 6m by 8m. Calculate the number of fittings required if each fitting is 100W and has an efficacy of 70 lumens/watt.
Pregunta 12
Pregunta
What maintenance should be carried out on a motor to ensure correct working:
Respuesta
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Continuity of windings
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Insulation resistance of the windings
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Insulation resistance between the windings and the case
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Changing of bearings
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Cleaning of luminaires in room
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Varnishing of shaft
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Monthly rotation of end plates
Pregunta 13
Pregunta
What types of earthing rely on the distributor's earthing arrangement?
Pregunta 14
Pregunta
How may PFC be obtained?
Pregunta 15
Pregunta
What earthing system has a combined earth and neutral conductor back to the transformer?
Pregunta 16
Pregunta
What is the maximum permitted voltage drop for a final power circuit?
Pregunta 17
Pregunta
A fault of negligible impedance between a live conductor and earth is known as?
Pregunta 18
Pregunta
How can earth fault loop impedance relate to the disconnection time of a circuit breaker?
Respuesta
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Zs relates to fault current
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Zs relates to RCD operating time
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Zs relates to nominal voltage
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Zs relates to full load current of the circuit
Pregunta 19
Pregunta
It is acceptable to run single core cables on metal tray
Pregunta 20
Pregunta
It is acceptable to run single core cables in metal trunking
Pregunta 21
Pregunta
What is the most suitable containment method for an outside motor to be connected to the electrical supply?
Respuesta
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SWA
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Metal conduit
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Metal trunking
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Cable basket
Pregunta 22
Pregunta
What does Ci relate to in cable calculations?
Respuesta
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Thermal insulation
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Above ordinary current
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Initial load current
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Installation
Pregunta 23
Pregunta
An installation with a nominal voltage of 230V has an external loop impedance of 0.2Ω and an external line to neutral voltage of 0.18Ω. What would the PFC be recorded on the test certificate?
Pregunta 24
Pregunta
When measuring PSSC the earth should be removed from the installation.
Pregunta 25
Pregunta
When measuring PEFC your terminals will be connected between line, neutral and the earth bar.
Pregunta 26
Pregunta
Single phase circuit is run in trunking with 3 other circuits. The ambient temperature for the room is 35° . The design current is 33A and the protective device an MCB to BS 60898. What is the minimum size 70° single-core thermoplastic cable that can be used taking into account current carrying capacity only?
Pregunta 27
Pregunta
There are 7 x 10mm², 5 x 6mm², 4 x 25mm² and 8 x 2.5mm² single phase circuits to be installed in trunking. Calculate the size required if all cables are PVC BS 6004 cables.
Respuesta
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50mm x 50mm
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75mm x 50mm
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75mm x 75mm
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100 x 75mm
Pregunta 28
Pregunta
A 5m run of conduit with 2 bends in it is to accommodate 2 ring final circuits of 2.5mm². Calculate the minimum size conduit to be used.
Pregunta 29
Pregunta
Electrocution doesn't always result in death
Pregunta 30
Pregunta
Which of the following should be included in a risk assessment
Respuesta
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Details of the hazard/risk
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Control measures to be applied
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Applicable standards to the risk assessment
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The evaluation of the risks
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Dates of review
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Company financial information
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Serial numbers of PPE equipment
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Time sheets
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The address of all contributors to the risk assessment
Pregunta 31
Pregunta
A store room must be illuminated to 200 lux. The size of the room is 9m x 10m, the room is kept fairly clean (M.F of 0.9) and due to god colour management and space ratios the U.F is 0.9. Calculate how many light fittings are to be used if each fitting contains 2 lamps of 2000 lumens each.