Sahithyan's S1 -- Electrical Fundamentals
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
- Turn off all main circuit breaker, RCCBs
- Turn on all MCBs and switches
- Unplug all appliances
- Set the appropriate scale on the tester
- Connect one probe to the earth bus bar
- Connect other probe to the live of the load
- Use
in the Megger. A higher voltage is used so that even minor insulation weaknesses can be noticed. - Test the circuit
If the reading is higher than
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
- Turn off main switches, MCBs, RCCBs - to disconnect the installation
- Unplug all appliances
- Turn on all switches (optional when testing earth wire)
- Set appropriate scale on the tester
- Connect one probe to the appropriate bus bar
- Connect other probe to the appropriate endpoint of the socket
- Use
in the Megger - Test the circuit
If the reading is less than