fuses 80 vs 100 percent rated

[mshields]

Are ALL fuses 100% rated. and in any event, are Gould Tri-onic TR200R 100% rated?

Thanks,

Mike

 

[jim dungar]

Are ALL fuses 100% rated. and in any event, are Gould Tri-onic TR200R 100% rated?

Yes fuses are 100% rated, however no fused switch <800A is.
The effect of UL98 Listing is that enclosed fuses are limited to 80% loading just like enclosed circuit breakers.

 

[templdl]

Are ALL fuses 100% rated. and in any event, are Gould Tri-onic TR200R 100% rated?

Thanks,

Mike

Should you be attempting to compare a 100% breaker to a fuse equivalent with a breaker you must sdtasrt with a breaker that is listed for 100% application. After which you must comply with there installation requirements to achieve the 100% rating.
Basically you have to start with the required enclosure. Then you must use 90degC tasted cable but applied at 75degC. The 90degC cable ampacity is based upon 100%continuoud +100% noncontinuos instead of 125%+100%. Which is where a posible cost savings begins, the opportunity to use a smaller cable. The breaker is sized to protect the cable and as such there is a remote chance to downsize a breaker frame. The cable is where the money is saved when there are longer rus but 100% fated breakers are more expensive too.
With this in mind how would a 100% rasted fuse if available be applied. With a 100% rated breaker it starts with 90degC cable sized 100+100.

 

[mshields]

thank you

thank you

very enlightening

 

[templdl]

very enlightening

The intersting thing is that the 80% actually comes from sizing the cable based upon 125% of the continuous load! Then you select the OCPD based upon the cable size which interesting enough ends up to be no more than 80% of the continuous load.