electrical

[ttttuunnddeerr]

can someone help me out how to check Single point ground on CT with multimeter or with megger?

 

[ScottyUK]

To prove the CT is earthed (grounded) at exactly one location? Lift the known earth connection and then megger the CT (or CT group) secondary winding to earth. If the reading is not very high then you another earth path. Reconnect the earth afterwards!

 

[buzzp]

Watch for hazardous voltages to build when you lift the ground if the CT's have current going through them during the test.

 

[FrozenE-]

buzzp brings up a good caution - but I would go one further and say do not try this with current going through the ct. CT circuits should not be disturbed while in service. Especially if you are not familiar with how to use simple test tools to perform this check. Open CT circuits are very hazardous and can start fires, damage/destroy equipment, or injure/kill you.

 

[ScottyUK]

Yes, completely agree. I'd assumed that this was a construction / commissioning activity without the circuit being energised, but very valid points.