Hello everyone,

I have a project where a 208V, 3 phase, 400 amp busway is being fed by a 400 amp fusible disconnect on the secondary side of a 150 KVA transformer. I'm working on the power systems study for this project and I am trying to find a fuse that will allow fast fault clearing and also provide a little bit of time delay for the downstream equipment on the busway (I know this is kind of a contradiction because fast fault clearing and time delay are two separate things). Currently they have chosen 400A TR Class RK5 time delay fuses and this does not allow mitigation of high arc flash hazard on the busway. The available fault current range from 6000 amps at the beginning of the bus duct to 3000 amps at the end. Just want to know if anyone has a good fuse type that they know of for reducing arc flash energy.

Best Regards

I have a project where a 208V, 3 phase, 400 amp busway is being fed by a 400 amp fusible disconnect on the secondary side of a 150 KVA transformer. I'm working on the power systems study for this project and I am trying to find a fuse that will allow fast fault clearing and also provide a little bit of time delay for the downstream equipment on the busway (I know this is kind of a contradiction because fast fault clearing and time delay are two separate things). Currently they have chosen 400A TR Class RK5 time delay fuses and this does not allow mitigation of high arc flash hazard on the busway. The available fault current range from 6000 amps at the beginning of the bus duct to 3000 amps at the end. Just want to know if anyone has a good fuse type that they know of for reducing arc flash energy.

Best Regards

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