600V vs 250V Disconnect

[Dustin Foelber]

I have a residential meter bank that has a 400A disconnect protecting the 11 meters. The disconnect has gone bad and I need to replace it. Due to shortages in my area I have the option to use a 600V 3 Phase Disconnect. Is this a code violation? I can not think of any reasonable issue why not using one phase and having the disconnect rated for the additional voltage would be an issue but I am not 100% certain? Maybe fuse rating AIC of the fuses changes if you feed it with 240V volt vs 600V? Any feedback would be greatly appreciated.

 

[electrofelon]

I have a residential meter bank that has a 400A disconnect protecting the 11 meters. The disconnect has gone bad and I need to replace it. Due to shortages in my area I have the option to use a 600V 3 Phase Disconnect. Is this a code violation? I can not think of any reasonable issue why not using one phase and having the disconnect rated for the additional voltage would be an issue but I am not 100% certain? Maybe fuse rating AIC of the fuses changes if you feed it with 240V volt vs 600V? Any feedback would be greatly appreciated.

No issue, as long as AIC is ok and the fuse class doesn't change, which could possibly change series ratings.

 

[jim dungar]

No issue, as long as AIC is ok and the fuse class doesn't change, which could possibly change series ratings.

Series ratings are based on specific fuse types. It is possible 240V equipment has never been series test with 600V fuses.

 

[electrofelon]

Series ratings are based on specific fuse types. It is possible 240V equipment has never been series test with 600V fuses.

Interesting idea. So you are saying, for example, that a series rating between a 250V rk5 fuse and a downstream device would not necessarily apply when using the 600v version with all other things being equal? Can you point to a source that states this specifically?

I looked through the Eaton series rating charts and it states "fuse class". It does not differentiate between different voltage ratings.

I looked at the Siemens book, and under the "240 volt fuses" section it does have a different section for "class T" and "class T (300v)". But it does not differentiate for class R fuses, which from a logical analysis based on the class T statement, would imply either could be used for a class R.