Verification and Testing Flashcards
Be able to describe each step briefly enough. (22 cards)
What chapter in the regulations covers verification and testing?
Chapter 6.
What are the 3 verification steps in order?
Inspection.
Testing.
Certification.
Give a brief description of inspection?
Requires no equipment and is done by a person with top notch knowledge of the regs.
There are two types of testings done. What are they?
Pre-connection and post-connection testing.
What are the 5 steps in pre-connection testing that we have covered for the exam?
Continuity of conductors, insulation resistance, detection of erroneous connections, polarity and voltage drop.
What are the 3 methods of testing continuity? Which of the 3 is most preferred and why?
Methods A1, A2 and B.
A1 is most preferred because it has the short circuit bridge at the DB while the person simply checks each socket.
What are we looking for in terms of continuity?
For a very small impedance/resistance reading, often below 0.5.
What conductors do we check for continuity and how?
Short circuit and check E and L conductors. Then do the same thing for E and N conductors.
How could a continuity test fail?
If there is a loose connection or a cut somewhere in the wire.
What conductors do we check for insulation resistance and how?
Test between both live conductors and earth and then only between the live conductors.
What should we maintain for a successful insulation resistance test?
Close all the switches and remove all the loads from the circuits.
What are we looking for in terms of insulation resistance?
A large value in ohms, normally mega ohms.
What are we looking for in terms of erroneous connections?
They check the integrity of protection devices, making sure L, N and E paths are properly connected and that the insulation between them is intact.
How do we connect the bridge to check for erroneous connections and what value are we looking for?
By connecting them L to L. We’re looking mega ohms.
What should be maintained so that the test for EC is successful?
Turn off all MCBs except the one you want to test. The same is done when testing each MCB.
Why are polarity tests done?
To verify that live and neutral conductors are correctly connected, preventing potential shocks and damage to appliances.
What else are we looking for in terms of polarity?
That the incoming supply point (power) is correct.
What is necessary for the voltage drop test?
That the measured value matches the calculated value and is within maximum percentage range.
What are the 2 post-connection tests that we are studying?
To confirm the effectiveness of automatic disconnection of supply and the effectiveness of additional protection.
What are we looking for in terms of the effectiveness of automatic disconnection of supply?
That the earth fault loop impedence is very low so that the protection devices can spot it real quick.
What are we looking for in terms of the effectiveness of additional protection?Also, what additional protection are we talking about?
RCDs is the main focus.
This test verifies the operation of RCDs once power is supplied to the distribution board.
From whom can you purchase test record sheets?
Safe Electric.
