Fuses for overload protection

[juicethief]

According to Article 430, fuses can be used for overload protection of motors. So for a 1 HP, 230V, 1? motor with a SF of 1.40 and a nameplate current rating of 7.1A, overload protection would be 8.875 or 9A (7.1 * 1.25). However, if I pull a class j fuse curve it appears that the fuse would take quite some time to open (if at all according to the curve). I know a smaller size fuse would work but the risk of nuisance tripping becomes an issue. Just curious as to whether there was a time limit or range that is acceptable?


Link to TCC from Littelfuse for JTD 6 thru 12A:
http://www.littelfuse.com/data/en/Time_Curve/FCC01-JTD-003(B).V01.PDF

 

[templdl]

This is the way I look at this:
What part of 430 specifically? 430 is a big article. Is there a chart related to that? I know that the MCP provides motor short circuit protection when used as part of a combination starter and as I can recall you are also allowed to use TM MCCBs also according to 430-52. I lieu of the MCP or MCCB fuses can be used also. All are used as disconnects.
I know that breakers are not intended to be used for motor OL protection as that's the job of the OLR in a starter. There are toggle switches that are intended for manual motor control that do have a motor OL built into them.
But I?m not aware where you are allowed to use a fuse, or even a breaker for that matter, for motor OL protection unless the motor manufacturer directs you to do as such.