Rock Quarries and Harmonics

[aelectricalman]

I want to get your take on where Quarries stand as a likely cuprit to have harmonics concerns.

I am going to provide a harmonics study of a rock quarry prior to installation of PFC equipment. Prior to this study I am just thinking about the large 300 hp motors and the many small 10 hp motors with drives and conveyors. (Mine type quarry). Do you normally see harmonics concerns that push you to install reactors on your caps. Do they normally exceed 3-4% Vthd in this environment?

Thanks for any insight.

 

[Besoeker]

I want to get your take on where Quarries stand as a likely cuprit to have harmonics concerns.

I am going to provide a harmonics study of a rock quarry prior to installation of PFC equipment. Prior to this study I am just thinking about the large 300 hp motors and the many small 10 hp motors with drives and conveyors. (Mine type quarry). Do you normally see harmonics concerns that push you to install reactors on your caps. Do they normally exceed 3-4% Vthd in this environment?

Thanks for any insight.

If they are variable speed drives, there will be quite a high harmonic current content. This will inevitably result on harmonic voltage distortion. How much will depend on how stiff your supply is.
If you can, you should also run a test with no drives running to background harmonic levels.

I put reactors on all PFC caps as a matter of practice. I've seen what can happen to the capacitors without them to take the risk of not doing so.

 

[robbietan]

I want to get your take on where Quarries stand as a likely cuprit to have harmonics concerns.

I am going to provide a harmonics study of a rock quarry prior to installation of PFC equipment. Prior to this study I am just thinking about the large 300 hp motors and the many small 10 hp motors with drives and conveyors. (Mine type quarry). Do you normally see harmonics concerns that push you to install reactors on your caps. Do they normally exceed 3-4% Vthd in this environment?

Thanks for any insight.

just in luck, I have just finished monitoring on a rock quarry here. not much VFDs here, however.

VTHD maxed at 4.5% in the 2 week monitoring