[AVRnj]

Thanks for the help guys. I have to finish replacing the bearings on my spindle and I will give the 15 amp fuses a try. If I still don't have enough power, I will go up to the 25.

[AVRnj]

Finished the bearings and tried out the 15 amp fuses in the existing fuse holders.

Works great, I am now getting 5400 RPM's. I have the pots set at the KBIC125 manuals default settings. I suspect if I had the higher amp fuses, I could get more, but I am really happy with 5400 RPM. I am getting 1700 RPM on my low speed pulley, and 5400 on my high.

Thanks much for the help guys, much appreciated.

[Fastest1]

I doubt a higher rated fuse would change anything. Since the KBIC has onboard protection. I will put a solid rod in there and report back. I cant imagine the foil wouldnt have allowed max. I am getting the 5400 on the spindle. Cant remember what the motor alone gets. I have that around here somewhere.

[AVRnj]

I doubt a higher rated fuse would change anything. Since the KBIC has onboard protection. I will put a solid rod in there and report back. I cant imagine the foil wouldnt have allowed max. I am getting the 5400 on the spindle. Cant remember what the motor alone gets. I have that around here somewhere.

Yeah, I don't see how it would change anything either, as I am running it off a 15 amp breaker anyway, but I am not an electrical expert, and perhaps there is some difference in a fuse vs. a breaker that does make sense.

I think if the breaker was higher, and the fuse was higher, you could probably push more power to it and maybe get more speed/torque out of it, but I do think the breaker would have to be higher for that to work.

[SCzEngrgGroup]

Yeah, I don't see how it would change anything either, as I am running it off a 15 amp breaker anyway, but I am not an electrical expert, and perhaps there is some difference in a fuse vs. a breaker that does make sense.

I think if the breaker was higher, and the fuse was higher, you could probably push more power to it and maybe get more speed/torque out of it, but I do think the breaker would have to be higher for that to work.

That would also defeat the whole purpose of having a fuse. The fuse should be large enough that is does not blow in normal use, but small enough that is DOES blow before something on the driver goes up in smoke. If you're not blowing a fuse, using a larger one will accomplish nothing of value, and could well mean the next time you over-load the spindle, you blow up the driver, instead of simply blowing the fuse.

Regards,
Ray L.

[hoss2006]

The manufacturer of the kbic specifies a 25 amp fuse for the ac line so you have little worry of blowing anything on the board, you aren't even running as high as they recommend.
My kbmm runs 25 amp fuses and I've pushed motors hard enough to pop a 15 amp circuit breaker a few times with no ill effects to the kbmm board. I've changed to running it from a 20 amp breaker line.
Hoss

[Al_The_Man]

The KBIC and most of the KB line, rely on fitting the correct HP resistor, this is used in conjunction with the CL, current limit pot.
There were also some variations in the SCR's fitted and the maximum current is also limited by the rating of the SCR's fitted.
As to fuses and breakers, breakers are typically time delayed, and fuses can range from time delay, fast blow and rectifier fuses, rectifier fuses are fitted to solid state equipment where a fast sweep through of the fuse occurs in order to save the S.S. components.
Al..

[Fastest1]

Btw, though I stated about putting a solid rod in place of the inline fuse. I was only talking about doing a no load test to see the effects if there are any on max rpm. The on board fuse was never to be changed so protection would never have been compromised. Just not a pressing issue. Right now, 5400 is so new to me and with the additional hp of the 1100 watt motor it is able to be aggressive enough for the moment.