different tests to be performed on any new or old wiring installation.

1. Inspection And Testing
of Wiring Installation
By Abhisek Bhandari

2. Inspection and Testing of Wiring Installation:
❖ After completing the new wiring or extending the old wiring, it should be inspected
and tested as per IE rules before connecting it to the supply. This test is being done
by using meggar of 500V.
❖ The following tests should be carried out on domestic wiring installation:
► Continuity Test/ Open Circuit Test
► Insulation Resistance Test between conductors
► Resistance Test between conductor and Earth
► Earth Continuity test
► Polarity Test

3. 1.) Continuity Test/ Open Circuit Test:

4. ► By performing this test, it is being checked whether any conductor of wire
is broken or not or is separated from any terminal or not. short circuit
between any wires is also being checked.
► Steps to perform this test:
1.Main MCB/switch is kept OFF. All fuses are being removed.
2. All lamps are kept in all holders, all switches are kept OFF, three pin
socket is shorted with small piece of wire. Regulators are kept in ON
position. All MCBs of distribution board/ sub circuits are kept ON.
3. E & L terminals of Megger are connected to outgoing terminals of
Main MCB.
4. Megger is being operated at rated speed and after that On the all
switches one by one and take the readings. If Megger shows Zero
Reading at ON position and Infinite Reading at OFF position then
continuity of wires is said to be OK. if in both positions if shows
Infinite reading then wire is said to be open and if it shows zero
reading in both positions the wire is said to be short circuited.
5. after performing this test, shorten links should be taken off.

5. 2.) Insulation Resistance Test between conductors:

6. ► By performing this test, Insulation quality of conducting wires is being
checked. Further it is also being checked whether any conductors are
shorten due to any reason or not.
► Steps to perform this test:
1.Main MCB/switch is kept OFF. all fuses are being removed.
2. All lamps and loads are removed from holders and sockets
respectively. all switches are kept ON. Regulators are kept in ON
position. All MCBs of distribution board/ sub circuits are kept ON.
3. E & L terminals of Megger are connected to outgoing terminals of
Main MCB.
4. Megger reading should not be less than 1 MΩ. According to I.E. rules
Insulation Resistance =

7. 3.)Resistance Test between conductor and Earth:

8. ► By performing this test, it is being checked whether Insulation of
conducting wire is broken or not or conducting wire is separated from any
terminal and whether it came in contact with metal parts or not.
► Steps to perform this test:
1. Main MCB/switch is kept OFF. all fuses are being removed.
2. All lamps are kept in all holders, all switches are kept ON, three pin
socket is shorted with small piece of wire. Regulators are kept in ON
position. All MCBs of distribution board/ sub circuits are kept ON.
3. Outgoing terminals of Main MCB are being shorted with wire and it is
connected with L terminal of Megger and E terminal of Megger is
connected to Earth.
4. Megger reading should not be less than 1 MΩ. According to I.E. rules
Insulation Resistance =
 after performing this test, shorten links should be taken off.

9. 4.) Earth Continuity test:

10. ► By doing this test, the continuity of Earthing Electrode is being checked
and also it is being checked that all metal parts are earthed or not.
► Steps to perform this test:
1. Megger’s E terminal is connected to earth and L terminal is connected
with Earth terminal of all sockets simultaneously. If Megger shows
Zero Reading then earth continuity is said to be OK.
2. Megger’s E terminal is connected to earth and L terminal is connected
all metal parts simultaneously. If Megger shows Zero Reading then
earth continuity is said to be OK. otherwise Earthing is not Ok.

11. 5.) Polarity Test:

12. ► According to I.E. rule, switch should be always kept in Phase wire. Which
is being checked by this test.
► Steps to perform this test:
1. Main MCB/switch is kept OFF. all fuses are being removed.
2. All switches are kept OFF.
3. Phase wire of the outgoing Terminal of Main switch/MCB is connected
with one terminal of Megger. Other Terminal of Megger is being
lengthen by wire and it is being checked at all switches’ incoming
terminal. and then by operating Megger at rated speed, reading is
taken.
4. if Megger shows Zero Reading then Polarity of the switch is said to be
OK. Otherwise connection should have to be interchanged.

13. THANK YOU