Loud CTs 3

[Palletjack]

Just how loud should 75kV CTs be when they are shunted?
I have some that are humming pretty good when shunted, then quiet down to nothing when they are unshunted and are attached to the 751A.[pre][/pre]

 

[waross]

Strange. there should be the same current whether shunted or connected to an instrument.
Is it possible that you may have bad connections on the shunts?

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[RRaghunath]

Agree with Bill.
You better do proper shunting, seems some loose connection (while shunting).

 

[scottf]

Agree on the above.

Assuming by shunting you mean shorting the secondary windings.

If the CT is making noise when the secondary is shorted and does not make noise when connected to a burden, then there is likely something wrong with your shorting and you may have actually placed in open circuit or very high burden on the secondary. Depending on how long this condition lasted, you could have damaged the CT.

The noise likely comes from the core being saturated, which can create a lot of heat and ultimately damage the secondary and/or primary insulation.

 

[Mbrooke]

@Scottf- star given- great explanation