Tripping bcz of Earth Leakage Relay

I suppose this is an ac 3 phase motor? right? at 15KW or more, correct me if I'm wrong, ac motor goes 3 phase.

1) Conduct insulation test of motor windings (L1, L2, L3) including earth what were the readings MegaOhms? See NEMA standards. You should get more than 76MegaOhms resistance to ground per line as per the NEMA standard.

2) Like wise, do an insulation test with the wires running from feeder to motor and earth leakage as well, what were the readings.

I suspect, you said you run only 2 wires for this, right? Must be lacking one, no wonder your ELR trip off. Is this be even possible?

OP said "two cables". This doesn't necessarily mean "two conductors".

It has become evident that there must be a shortage of qualified electricians in the world.

I say that because of the astronomical number of people who come here and ask the forum to fix their electrical problems for them. Usually without providing any meaningful information.

And of course expecting to get their problems explained to them and solved for free.

Either it's a shortage of electricians or an excess of cheap-ased people who want others to work for them for free.

I'll go with # 2.

Hire a qualified electrician!!!!!!!!!

Is it tripping during starting or after how long,did you measure starting current,time,vd etc

What kind of starter is used,is it VFD,if so contact VFD specialists.

Mohsin Hamid,

You haven't come back with details to the queries of other posters. Let us know if you have solved the problem and details thereof.

In case you haven't, here is my penny's worth: Hope the ELR is connected to CBCT.

* Please check the power cables are centered properly. You mentioned there are two cables (3-core cable each, hopefully). Both have to be reasonably centered in the CBCT window reasonably.

* Presuming the cables are armoured type. If true, is the armour brought back through the CBCT window? This is important and has been responsible for many a spurious trip.

* The pickup setting of ELR - make sure the setting is at least 6A. Too sensitive setting can cause spurious trip during motor start

Look forward to hearing from you.

Now changed the setting of ELR higher. Before it was 2 Amps. Now it runs good. How to calculate the ELR setting. I had heared ELR setting shld be as low as possible. Since the leakage will be very minimum why current setting shld be made to 5 Amps..??

Have you made any effort to learn, "How to calculate the ELR setting"?

Where have you looked for the answer, so far?

Or do you just want us to do that for you too?