Installation Tests

After an electric installation is done, it must be tested for faults, to ensure the safety of users and electrical appliances. Megger or insulation resistance tester can be used for these tests.

Insulation test

To make sure there are no short circuits and the circuit is properly insulated.

Procedure

1. Turn off all main circuit breaker, RCCBs
2. Turn on all MCBs and switches
3. Unplug all appliances
4. Set Function to $500\,\text{V}$ on the Megger. A higher voltage is used so that even minor insulation weaknesses can be noticed.
5. Connect one probe to the earth bus bar
6. Connect other probe to the live of the load
7. Test the circuit

If the reading is higher than $1\,\text{M}\Omega$, test is passed. $$

Continuity test

To check if current passes through 2 points of the circuit continuously. Can be checked for all 3 wires (live, neutral and earth).

Procedure

1. Turn off main switches, MCBs, RCCBs - to disconnect the installation
2. Unplug all appliances
3. Turn on all switches
   Optional when testing earth wire
4. Set Functino to $\Omega$ on the Megger
5. Connect one probe to the appropriate bus bar
6. Connect other probe to the appropriate endpoint of the socket
7. Test the circuit

If the reading is less than $10\,\Omega$, test is passed. $$