Name: Omar Osama Mohamed

Subject: Electrical installations

About: Report of Electrical Installation

Testing
  Introduction:
Electrical installation tests are a crucial aspect of ensuring the safety,
functionality, and compliance of electrical systems in various settings,
including residential, commercial, and industrial buildings. These tests are
performed to assess the integrity of electrical installations, identify potential
issues, and confirm that the system meets the required standards and
regulations. The tests are typically conducted during the installation process,
periodic maintenance, or as part of regulatory inspections

Types of Tests

 1. Continuity Test:
The purpose of continuity measurement is to check the continuity of the protective
conductors, the main and supplementary equipotential bonds and Protective
conductors are the wires that connect the exposed metal parts of electrical
equipment to the earth terminal, providing a low-resistance path for fault currents
to flow to the ground and trip the circuit breaker or fuse. Equipotential bonding is
the connection of all the metal parts that are not part of the electrical system, such
as pipes, ducts, and structural elements, to the main earthing terminal, creating a
zone of equal potential and preventing dangerous voltage differences. The test is
carried out using a measuring instrument capable of generating a no-load voltage
of 4 to 24 V (DC or AC) with a minimal current of 200 mA. Continuity test is
covered by the EN 61557-4 standard. The measured resistance must be lower than
a threshold specified by the standard applicable to the installation tested, which is
usually 0.2 Ω. As the resistance value is low, the resistance of the measurement
leads must be compensated, particularly if very long leads are used
The method and device for performing a continuity test are as
follows:
• Attach the continuity tester or ohmmeter's test leads to the earth terminal and the
protective conductor.
• Turn on the gadget and check the resistance value on the indicator or display.
• Repeat the test on all of the installation's equipotential bonding and protective
conductors.
• Take note of the test results and contrast them with the permitted ranges.
The result: A low resistance value for each protective conductor and equipotential
bonding should be shown in the continuity test results, indicating a strong
connection and continuity. A break or a loose connection in the equipotential
bonding or protective conductor indicates a high or infinite resistance value, which
needs to be fixed or replaced.

Application: Checks wiring, switches, and other connections for breaks or

interruptions.

 2. Insulation Resistance Test:

The insulation is intended to prevent any contact with live parts and withstanding
mechanical, chemical, electrical and thermal stresses. Insulation test discloses
insulation faults caused by pollution, moisture, deterioration of insulation materials
etc. Insulation resistance measurement is covered by the IEC / EN 61557-2
standard. The power must be switched off and the installation must be
disconnected before performing this test to ensure that the test voltage will not be
applied to other equipment electrically connected to the circuit to be tested,
particularly devices sensitive to voltage surges.
-Insulation resistance should be measured between:
• Line conductors
• Line and PE conductors
• Line and Neutral conductors
• Neutral and PE conductors

The insulation resistance test is performed with a DC voltage on a dead system and
the resistance must be above the minimum limit set out in the appropriate
standards and regulations. Limit values for electrical installations acc. to IEC
60364-6. An insulation resistance test is performed by applying a high voltage
(usually 500V or 1000V) between the live conductors and the earth, and measuring
the resistance with an insulation tester or a megger.
The method and device for performing an insulation resistance test are
as follows:

 Disconnect the power supply and isolate the installation from the source.
 Connect the test leads of the insulation tester or the megger to the live
conductors and the earth terminal.
 Switch on the device and apply the test voltage for a specified duration
(usually 1 minute).
 Read the resistance value on the display or the indicator.
 Repeat the test for all the live conductors and the earth in the installation.
 Record the test results and compare them with the acceptable values.

The result: a high resistance value for each live conductor and the earth,
indicating a good quality ,If the resistance value is below the acceptable value, it
means that there is a defect ,which should be repaired or replaced.

Application: Tests insulation in cables, wires, motors, transformers, and other

electrical components.

 3. Polarity Test:
A polarity test in the context of electrical installations is a procedure to verify the
correct connection of live, neutral, and ground conductors in a circuit. Ensuring
proper polarity is essential for the safe and effective operation of electrical devices
and appliances. The polarity test is commonly performed in outlets, electrical
panels, and various electrical devices to confirm that the wiring is correctly aligned.
The primary purpose of the polarity test is to identify and confirm the correct wiring
configuration to prevent electrical hazards and ensure the proper functioning of
electrical equipment. It involves checking the alignment of live (hot), neutral, and
ground wires.
The method and device for performing a polarity test are as follows:

 A test shall be carried out in a two-wire installation to verify that all the
switches in the circuit are fitted in the same conductor throughout the
supply.
 In a three-wire or a four-wire installation, a test shall be carried out to verify
every non-linked single pole switch is fitted in a conductor labeled or marked
for connection to one of the phase conductors of the supply.
 The installation shall be connected to the supply for testing. A test lamp shall
test the terminals of all switches, one lead of that is connected to the earth.
 Connect the test leads of the test lamp or the voltage tester to the neutral
conductor and the earth terminal.
 Glowing the test lamp to its full intensity when the switch is in the "on"
position irrespective of the appliance is in position or not shall indicate that
the switch is connected to the right polarity.
 Repeat the test for all the switches, sockets, and lamps in the installation,
using the appropriate terminals.
 Record the test results and compare them with the expected values.

The result: The live, neutral, and ground conductors are correctly connected. The
electrical installation is in accordance with the wiring standards and is considered
safe and functional.

Application: Ensures proper wiring in outlets, appliances, and other electrical

devices.

 References/Resources:
 https://www.instrumart.com/assets/Fluke-basic_electrical_installation_testing.PDF

 https://www.yourelectricalguide.com/2019/10/methods-of-electrical-wiring-
testing.html

 https://www.tester.co.uk/blog/electrical/electrical-installation-safety-testing-a-guide/

 https://theconstructor.org/practical-guide/material-testing/types-tests-internal-
electrical-installations/557305/