Fused Switch

[mstrlucky74]

Have to replace fuses in a 1600a fused switch in a 3 phase switchboard. There are 3 phase conductors, 1 neutral and 1 ground. I would only require 3 fuses just for the phase conductors, correct? Just making sure...lol..:dunce:

BTW I'm replacing 1200a fuses with 1600a....Could there be an issue with the fuse holder/slots since they are bigger fuses?

 

[Jraef]

Have to replace fuses in a 1600a fused switch in a 3 phase switchboard. There are 3 phase conductors, 1 neutral and 1 ground. I would only require 3 fuses just for the phase conductors, correct? Just making sure...lol..:dunce:

BTW I'm replacing 1200a fuses with 1600a....Could there be an issue with the fuse holder/slots since they are bigger fuses?

You can never fuse grounded cunductors, unless you have a system by which all other associated ungrounded conductors will open if a grounded conductor fuse clears. If properly equipped with blown fuse indicators and a trip coil, a "Pringle Switch" (aka Bolted Pressure Switch) can accomplish that and at 1200-1600A, you are in the size range where that is used. But suffice to say this is extremely rare. You will only encounter 3 fuses on the phase conductors in all likelihood.

As to the fuse size, maybe, maybe not. Fuse holders and switches come in specific size ranges, two of which are 1200A and 1600A. If you happen to have a 1600A switch into which someone installed 1200A fuses, then you should be fine (other than the conductor size issues). But because these are very expensive, it's more likely someone bought just what they needed so you will find a 1200A switch, which means you will be prevented from putting in anything larger than 1200A fuses.

Ah, just noticed you said it IS a 1600A switch, so you should be fine.

 

[mstrlucky74]

You can never fuse grounded cunductors, unless you have a system by which all other associated ungrounded conductors will open if a grounded conductor fuse clears. If properly equipped with blown fuse indicators and a trip coil, a "Pringle Switch" (aka Bolted Pressure Switch) can accomplish that and at 1200-1600A, you are in the size range where that is used. But suffice to say this is extremely rare. You will only encounter 3 fuses on the phase conductors in all likelihood.

As to the fuse size, maybe, maybe not. Fuse holders and switches come in specific size ranges, two of which are 1200A and 1600A. If you happen to have a 1600A switch into which someone installed 1200A fuses, then you should be fine (other than the conductor size issues). But because these are very expensive, it's more likely someone bought just what they needed so you will find a 1200A switch, which means you will be prevented from putting in anything larger than 1200A fuses.

Ah, just noticed you said it IS a 1600A switch, so you should be fine.

Thanks....BTW 1600A fuses for this switch about $300 each

 

[Besoeker]

Thanks....BTW 1600A fuses for this switch about $300 each

Sounds about right. Have you checked Cooper Bussmann or their distributors?

 

[mstrlucky74]

Sounds about right. Have you checked Cooper Bussmann or their distributors?

Not yet.