run fuses in parrallel? 1

[victa1288]

I did some study regarding the possibility of using fuse -contactor scheme for 10kV motor. I have noticed that there are no large rating fuses which can suit large motor application. The max. 12kV fuse for motor protection is rated 200A. Apparently it is not good for some larger motors as shown in the TCC. The manufacturer recomend that I use fuses in parallel to increase fuse ampacity.

I am not sure it is appropriate or not? What is the disvantage of doing so?

Thank you in advance.

 

[Mike2468]

Using parallel fuses is common. Cooper Bussman permanently connects both to a mounting bracket so both are replaced at the same time. Otherwise, one fuse may clear, while the other is stressed, which would lead to additional open fuses on a regular basis.

 

[peebee]

Per NEC 240.8: "Fuses and circuit breakers shall be permitted to be connected in parallel where they are factory assembled in parallel and listed as a unit. Individual fuses, circuit breakers, or combinations thereof shall not otherwise be connected in parallel."

 

[victa1288]

Thank you for your response.

As per NEC, fuses connected in parallel should be factory assembled and listed as a unit. That means, this kind of products are called 2 barrel or 3 barrels per phase and should be listed in their catlogue?

Is my understanding correct?

Thanks.

 

[dpc]

Yep.