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firemanowl
Here are questions 11 - 20, I have also found the long answer section with answers so will post shortly. I apologise if there are any mistakes but feel free to offer any corrections.
11 State the meaning of:
a) IP 2X
b) IP 4X
c) IP XXB (3 marks)
a) protection against a sphere of 12.5mm diameter by 80mm length.
b) Protection against a wire o1mm diameter (Standard Test Wire)
c) Protection against a ‘Standard Test Finger’ only.
12 State THREE areas within a construction site which are NOT subject to Part 7 of BS 7671:2008. (3 marks)
i) toilets
ii) mess rooms
iii) site offices.
13 List FOUR items of information that are required to be indicated on diagrams, charts etc., for use by the inspecting engineer. (3 marks)
i) type and composition of circuits
ii) method of protection against electric shock
iii) any circuit vulnerable to a particular test
iv) the identification and location of any device performing the functions of protection, isolation and switching.
14 State SIX methods of Fault Protection. (3 marks)i) Automatic Disconnection of Supply (ADS)
ii) Double or Reinforced Insulation (Class II)
iii) Non-Conducting Location
iv) Earth-Free Equipotential Bonding
v) Electrical Separation
vi) Extra Low Voltage (SEVV or PELV)
15 State:
a) the instrument used for a ‘dead’ polarity test
b) an instrument that may be used for a ‘live; polarity test
c) why certain E14 & E27 Edison screw lampholders do not require to be checked for polarity. (3 marks)
a) Low Resistance D.C. Ohmmeter
b) GS.38 Voltage Indicator testing between Live and Earth
c) Certain E14 & E27 lampholders have a non-metallic ‘screw’ insert. Contact with the lamp itself is made in the base of the fitting therefore not creating a risk of electric shock to a person inserting the lamp who may be touching the metal screw of the lamp.
16 State the units of measurement that are displayed on the following test instruments:
a) low resistance ohmmeter
b) insulation resistance tester
c) prospective fault current tester. (3 marks)
a) Ohms (Ω)
b) Mega Ohms (MΩ)
c) Kilo Amps (kA)
17 A continuity test between P and N is conducted on a ring final circuit comprising 2.5 mm[SUP]2[/SUP]/1.5mm[SUP]2 [/SUP]thermoplastic (pvc/pvc) cable. Readings at two socket outlets close to each other indicate an increased value to that of all the other sockets. State:
a) the instrument used for the test
b) TWO possible reasons for the increased readings. (3 marks)
a) A Low Resistance D.C. Ohmmeter.
b) i) The socket is a spur from another socket.
ii) There is a unacceptable bridge or interconnection in the ring final circuit.
18 Identify the type of circuit that would require the following applied voltages when conducting an insulation resistance test
a) 250 V dc
b) 500 V dc
c) 1000 V dc (3 marks)
a) An Extra-Low Voltage circuit (SELV or PELV).
b) Low Voltage up to 500 volts.
c) Circuit above 500 volts.
19 BS 7671:2008 requires that the ‘live’ polarity is verified before installation circuits are energised. State:
a) Why the live polarity test is needed
b) at what part of the installation the test would normally be made
c) ONE method of carrying out the test. (3 marks)
a) To confirm that the Supply Authority’s Polarity is indeed correct.
b) At the Origin.
c) Using a GS 38 approved Voltage Indicator and testing between the incoming Line and Earth conductors.
20 State three methods of ascertaining the value of prospective short circuit current at the origin of a TN-C-S system.
(3 marks)
Measurement, Enquiry or Calculation.
11 State the meaning of:
a) IP 2X
b) IP 4X
c) IP XXB (3 marks)
a) protection against a sphere of 12.5mm diameter by 80mm length.
b) Protection against a wire o1mm diameter (Standard Test Wire)
c) Protection against a ‘Standard Test Finger’ only.
12 State THREE areas within a construction site which are NOT subject to Part 7 of BS 7671:2008. (3 marks)
i) toilets
ii) mess rooms
iii) site offices.
13 List FOUR items of information that are required to be indicated on diagrams, charts etc., for use by the inspecting engineer. (3 marks)
i) type and composition of circuits
ii) method of protection against electric shock
iii) any circuit vulnerable to a particular test
iv) the identification and location of any device performing the functions of protection, isolation and switching.
14 State SIX methods of Fault Protection. (3 marks)i) Automatic Disconnection of Supply (ADS)
ii) Double or Reinforced Insulation (Class II)
iii) Non-Conducting Location
iv) Earth-Free Equipotential Bonding
v) Electrical Separation
vi) Extra Low Voltage (SEVV or PELV)
15 State:
a) the instrument used for a ‘dead’ polarity test
b) an instrument that may be used for a ‘live; polarity test
c) why certain E14 & E27 Edison screw lampholders do not require to be checked for polarity. (3 marks)
a) Low Resistance D.C. Ohmmeter
b) GS.38 Voltage Indicator testing between Live and Earth
c) Certain E14 & E27 lampholders have a non-metallic ‘screw’ insert. Contact with the lamp itself is made in the base of the fitting therefore not creating a risk of electric shock to a person inserting the lamp who may be touching the metal screw of the lamp.
16 State the units of measurement that are displayed on the following test instruments:
a) low resistance ohmmeter
b) insulation resistance tester
c) prospective fault current tester. (3 marks)
a) Ohms (Ω)
b) Mega Ohms (MΩ)
c) Kilo Amps (kA)
17 A continuity test between P and N is conducted on a ring final circuit comprising 2.5 mm[SUP]2[/SUP]/1.5mm[SUP]2 [/SUP]thermoplastic (pvc/pvc) cable. Readings at two socket outlets close to each other indicate an increased value to that of all the other sockets. State:
a) the instrument used for the test
b) TWO possible reasons for the increased readings. (3 marks)
a) A Low Resistance D.C. Ohmmeter.
b) i) The socket is a spur from another socket.
ii) There is a unacceptable bridge or interconnection in the ring final circuit.
18 Identify the type of circuit that would require the following applied voltages when conducting an insulation resistance test
a) 250 V dc
b) 500 V dc
c) 1000 V dc (3 marks)
a) An Extra-Low Voltage circuit (SELV or PELV).
b) Low Voltage up to 500 volts.
c) Circuit above 500 volts.
19 BS 7671:2008 requires that the ‘live’ polarity is verified before installation circuits are energised. State:
a) Why the live polarity test is needed
b) at what part of the installation the test would normally be made
c) ONE method of carrying out the test. (3 marks)
a) To confirm that the Supply Authority’s Polarity is indeed correct.
b) At the Origin.
c) Using a GS 38 approved Voltage Indicator and testing between the incoming Line and Earth conductors.
20 State three methods of ascertaining the value of prospective short circuit current at the origin of a TN-C-S system.
(3 marks)
Measurement, Enquiry or Calculation.
